Case Reports in Pathology The latest articles from Hindawi Publishing Corporation © 2016 , Hindawi Publishing Corporation . All rights reserved. Primary Neuroendocrine Carcinoma of the Breast: Histopathological Criteria, Prognostic Factors, and Review of the Literature Thu, 20 Oct 2016 13:05:48 +0000 We present here a case of a 42-year-old woman diagnosed with primary neuroendocrine carcinoma of the breast (NECB). We discuss the importance of histological criteria for primary neuroendocrine mammary carcinoma, established by WHO in 2003 and 2012. After an overview of different cases of primary neuroendocrine carcinoma of the breast published in the literature, we present information about differential diagnosis, prognostic factors, and surgical and adjuvant treatment. Prognosis of NECB is not different from that of other invasive breast carcinomas and the most important prognostic factor is tumor grade (G). There is no standard treatment and patients should be treated similarly to patients with invasive ductal carcinoma, NOS (not otherwise specified), whose choice of therapy depends on tumor’s size, degree of differentiation, clinical stage, and hormonal status. Lena Marinova, Doroteya Malinova, and Snezhinka Vicheva Copyright © 2016 Lena Marinova et al. All rights reserved. Adenomatous Polyps in Adolescent Girl and Boy: A Report of Two Cases Wed, 19 Oct 2016 11:17:13 +0000 A polyp is defined as a mass of the mucosal surface that protrudes into the lumen of the gastrointestinal tract. Neoplastic epithelial polyps are classified histologically as either benign adenoma or malignant carcinoma. The colonic polyps that most commonly present in children occur sporadically and individually and are of the juvenile type; they are most frequently associated with painless rectal hemorrhage (which is the most common symptom). Adenomatous polyps are similar to other nontumoral polyps, and it is very rare for children to have symptoms other than rectal bleeding. This report describes two rare cases of polyps in pediatric patients. An 11-year-old girl presented with tubulovillous adenoma and a 13-year-old boy with tubular adenoma; both patients complained of rectal hemorrhage as well as anemia and abdominal pain. Epithelial adenoma is a tumor that is rarely found in adults or children. Colonoscopic perforation and biopsy are mandatory for establishing a definitive diagnosis and avoiding medical mismanagement. Laleh Vahedi Larijani, Maryam Ghasemi, and Hassan Karami Copyright © 2016 Laleh Vahedi Larijani et al. All rights reserved. An Unusual Case of Paraganglioma of the Broad Ligament Presenting as Cystic Mass Thu, 13 Oct 2016 13:58:53 +0000 In clinical practice, broad ligament (BL) tumors are seldom encountered. Paraganglioma of the BL is exceedingly rare entity. Here we present an unusual case of broad ligament paraganglioma, presenting as a cystic mass, in a 50-year-old postmenopausal female. A high degree of suspicion along with detailed immunohistopathological work-up is needed for arriving at an accurate diagnosis. Siddhi Gaurish Sinai Khandeparkar, Maithili Mandar Kulkarni, Vandana Gaopande, Avinash Joshi, and Pushpalata Naphade Copyright © 2016 Siddhi Gaurish Sinai Khandeparkar et al. All rights reserved. Disseminated Cerebrospinal Embryonal Tumor in the Adult Thu, 13 Oct 2016 08:34:58 +0000 Introduction. According to the 2016 World Health Organization classification of Tumors of the Central Nervous System, the term Primitive Neuroectodermal Tumor has been replaced by the term Embryonal Tumor (ET). We present a case of disseminated cerebrospinal ET presenting in an adult patient. Illustrative Case. A 49-year-old male presenting with low back pain, dysuria, and hypoesthesia of the lower extremities referred to our emergency department. Brain and whole spine contrast-enhanced MRI documented a diffusively disseminated heterogeneous neoplasm with intradural extra- and intramedullary involvement of the cervicothoracic tract and cauda equina. A primary biopsy of the lumbosacral localization was performed through L5 bilateral laminectomy. Histologic diagnosis was Embryonal Tumor Not Otherwise Specified. The patient underwent chemotherapy with postoperative adjuvant alternating Vincristine-Doxorubicin-Ifosfamide (VAI) and Ifosfamide-Etoposide (IE). Discussion. Spinal ETs are exceedingly rare especially when presenting in the adult patient. Neurosurgical and oncologic management is still unclear. When feasible, surgical removal should always be performed to obtain a histologic diagnosis. Postoperative adjuvant therapy might entail both chemo- and radiotherapy; however a consensus on this matter is still lacking. Alessandro Caporlingua, Daniele Armocida, Federico Caporlingua, Gennaro Lapadula, Grazia Maria Elefante, Manila Antonelli, and Maurizio Salvati Copyright © 2016 Alessandro Caporlingua et al. All rights reserved. Ovarian Carcinosarcoma and Its Association with Mature Cystic Teratoma and Primary Tubal Carcinoma Tue, 11 Oct 2016 09:19:56 +0000 Introduction. Carcinosarcoma is an uncommon form of ovarian cancers, classified as being part of the group of mixed epithelial and mesenchymal tumors. The occurrence of carcinosarcoma in association with a mature cystic teratoma and synchronous tubal carcinoma is very rare. Case Report. A 69-year-old woman presented with a pelvic mass. An abdominal computerized tomographic scan detected a 15 cm right pelvic mass which was suggestive of malignant transformation of a dermoid cyst. Intraoperative, bilateral ovarian masses (left 10 cm and right 12 cm) with diffuse peritoneal metastatic nodules were identified. Histologically, the left ovarian mass was composed of 2 components including carcinosarcoma and mature cystic teratoma, whereas the right ovarian mass represented a mature cystic teratoma with serosal surface involvement of high-grade serous adenocarcinoma. The left fallopian tube was macroscopically unremarkable but contained a 5.0 mm focus of high-grade serous adenocarcinoma in the distal part, with adjacent serous tubal intraepithelial carcinoma. Conclusion. As the fallopian tube has recently been proposed to be an origin for a majority of pelvic or ovarian high-grade serous adenocarcinomas, tubal carcinoma may be the origin for ovarian carcinosarcomas through an epithelial-mesenchymal transition. The coexistence of ovarian carcinosarcoma and teratoma in the present case should represent a collision tumor. Sunida Rewsuwan, Nopporn Satabongkoch, Prapaporn Suprasert, and Surapan Khunamornpong Copyright © 2016 Sunida Rewsuwan et al. All rights reserved. Hepatoid Adenocarcinoma of the Urachus Mon, 10 Oct 2016 10:27:36 +0000 Hepatoid adenocarcinoma of the urachus is a rare condition. We present the case of a 51-year-old female who developed abdominal pain and hematuria. Pelvic magnetic resonance imaging (MRI) reported an urachal mass with invasion to the bladder that was resected by partial cystectomy. On light microscopy the tumor resembled liver architecture, with polygonal atypical cells in nest formation and trabecular structures. Immunochemistry was positive for alfa-fetoprotein (AFP) and serum AFP was elevated. Hepatoid adenocarcinomas have been reported in multiple organs, being most commonly found in the stomach and the ovaries. Bladder compromise has been rarely described in the literature, and it has been associated with poor prognosis, low remission rates, and early metastasis. Daniel Fernando Gallego, Carlos Muñoz, Carlos Andrés Jimenez, and Edwin Carrascal Copyright © 2016 Daniel Fernando Gallego et al. All rights reserved. Histiocytic Sarcoma in a Kidney Transplant Patient: A Case Report and Review of the Literature Mon, 03 Oct 2016 09:33:20 +0000 Objective. Histiocytic sarcoma (HS) is an aggressive neoplasm with only limited number of reported series of cases and rare case reports of occurrence as a posttransplant neoplastic disorder. The etiology and pathogenesis of the disease is unknown and the optimal treatment is still under investigation. We describe an unusual case of HS in a patient with a remote history of kidney transplant. Method and Results. A 54-year-old male with a remote history of renal transplantation under maintenance immunosuppression presented with features of sepsis. CT abdomen revealed multiple heterogeneous masses in bilateral native kidneys and liver and enlarged abdominal and retroperitoneal lymph nodes. Viral serology work-up was negative. Needle core biopsy revealed a highly undifferentiated neoplasm comprised of highly atypical large cells with eosinophilic to vacuolated cytoplasm and hemophagocytosis. Extended panel of immunohistochemistry proved histiocytic lineage for the tumor cells. The patient expired 2 weeks following the diagnosis. Conclusion. Our case along with three previously published case reports raised the possibility of HS as a treatment-related neoplasm or a posttransplantation neoplastic disorder in solid organ transplant recipients. Maressa Pollen, Siraj El Jamal, Jack Lewin, and Varsha Manucha Copyright © 2016 Maressa Pollen et al. All rights reserved. Metastatic Papillary Thyroid Carcinoma with Multifocal Synchronous Transformation to Anaplastic Thyroid Carcinoma Wed, 28 Sep 2016 11:52:52 +0000 Papillary thyroid carcinoma is a common malignancy to affect the thyroid and is typified by a nonaggressive nature and low rates of mortality. In contrast, anaplastic thyroid carcinoma is the most aggressive thyroid malignancy with a mortality rate of nearly 90% and survival typically of only six months after the diagnosis is made. The transformation of papillary thyroid carcinoma to anaplastic thyroid carcinoma is well documented in the literature but is uncommon and in most instances is reported as a case report or small series only. Transformation of papillary thyroid carcinoma to anaplastic thyroid carcinoma usually takes place in the thyroid itself or in the adjacent lymph nodes. Only on rare occasions does a transformation occur in a papillary thyroid carcinoma metastasis outside of these locations. In the present case report and subsequent discussion we highlight an unusual case of PTC with transformation to anaplastic thyroid carcinoma, which is shown to involve numerous locations to include near total lung parenchyma obliteration. We also discuss the differential diagnostic challenges when faced with a thyroid malignancy that is negative for thyroglobulin. Mark Benedict and Jose Costa Copyright © 2016 Mark Benedict and Jose Costa. All rights reserved. Unusual Case of a Proptosed Eye: Isolated Right Maxillary Neurofibroma Wed, 28 Sep 2016 10:12:05 +0000 Neurofibroma is a slow growing benign tumour of the peripheral nerve sheath which is frequently associated with neurofibromatosis type 1 (Prakash et al., 2014). Isolated solitary occurrence of neurofibroma in the maxillary sinus is rare with only 29 reported cases in the literature. We present a rare case of a 70-year-old gentleman who was referred to ENT with a right maxillary sinus neurofibroma with extension into the right inferior orbit. He has significant proptosis, ptosis, and limitation in abduction of the right eye. He has a complicated past history of multiple neurofibromas which were completely excised. Craniofacial MRI shows a large mass filling the right maxillary antrum extending anteriorly into subcutaneous tissue towards nasal ala and posterolaterally into inferior temporal fossa and superiorly into orbit and cavernous sinus involvement. Biopsy of the right maxillary mass revealed cellular spindle cell tumour with wavy collagen bundles within myxoid stroma which is consistent with a neurofibroma. Patient’s case was discussed in the skull-base MDT and he has been referred to a specialist center for surgical removal of the neurofibroma with reconstructive surgery. Despite the rarity of this disease, otorhinolaryngologist should consider a possibility of neurofibroma of the paranasal sinuses. Darren Yap, Hannah Fox, and Julia Addams-Williams Copyright © 2016 Darren Yap et al. All rights reserved. Incidentally Detected Kaposi Sarcoma of Adrenal Gland with Anaplastic Features in an HIV Negative Patient Mon, 26 Sep 2016 13:40:11 +0000 Kaposi sarcoma (KS), a vascular tumor caused by infection with human herpesvirus 8 (HHV8), is a systemic disease that can present with cutaneous lesions with or without visceral involvement. Very few cases of KS, most of which were associated with AIDS, have been reported in the adrenal gland. Anaplastic transformation of KS is a rare clinical presentation known as an aggressive disease with local recurrence and metastatic potential. We report here a 47-year-old HIV negative male presented with extra-adrenal symptoms and had an incidentally detected anaplastic adrenal KS exhibited aggressive clinical course. To the best of our knowledge, this is the first case of anaplastic primary adrenal KS without mucocutaneous involvement but subsequently developed other side adrenal metastases in an HIV negative patient. Zeliha Esin Celik, Murat Celik, Erdem Sen, Hakan Cebeci, Ozlem Ata, and Cagdas Yavas Copyright © 2016 Zeliha Esin Celik et al. All rights reserved. Metastatic Gastrointestinal Adenocarcinoma with Osteoblastic Activity: A Case Report of Esophageal and Colonic Primaries Thu, 22 Sep 2016 13:34:42 +0000 Adenocarcinoma with osteoblastic metastases is classically seen in prostate, breast, and lung primaries. Less common primary sites include thyroid, kidney, and stomach. We present two cases of primary gastrointestinal adenocarcinoma with metastatic osteoblastic activity from two previously unreported sites. The first case represents an esophageal adenocarcinoma arising in a background of intestinal metaplasia that metastasized with osteoblastic activity to the deltoid muscle. The second case demonstrates a Stage IV sigmoid colon adenocarcinoma with osteoblastic metastases to the liver and lymph nodes. The findings indicate that metastases from various gastrointestinal primary adenocarcinomas can have prominent bone formation. Brett Matthew Lowenthal, Ahmed S. Shabaik, and Mark A. Valasek Copyright © 2016 Brett Matthew Lowenthal et al. All rights reserved. Idiopathic Transverse Myelitis Mimicking an Intramedullary Spinal Cord Tumor Thu, 08 Sep 2016 18:10:02 +0000 The differential diagnoses for spinal cord lesions include spinal tumors and inflammatory processes. The distinction between these pathologies can be difficult if solely based on imaging. We report for the first time to our knowledge a case of idiopathic transverse myelitis (ITM) mimicking a discrete cervical spinal lesion in a 66-year-old man who presented with gait instability and neck pain. The patient’s symptoms failed to resolve after an initial course of steroid therapy. Surgical biopsy confirmed the diagnosis of ITM. Subsequent treatment with dexamethasone resulted in complete resolution of the symptoms as well as the intramedullary enhancement. ITM is most common in the cervical and thoracic spine, spanning 3-4 spinal segments. It usually occupies more than 50% of the cross-sectional area of the spinal cord and tends to be central, uniform, and symmetric. It exhibits patchy and peripheral contrast enhancement. These criteria are useful guidelines that help distinguish ITM from neoplastic spinal lesions. A decision to perform biopsy must take into consideration the patient’s clinical symptoms, the rate of progression of neurological deficits, and the imaging characteristics of the lesion. Surgical biopsy for questionable lesions should be reserved for patients with progressive neurological deficits refractory to empirical medical therapy. Andrew A. Fanous, Nathan P. Olszewski, Lindsay J. Lipinski, Jingxin Qiu, and Andrew J. Fabiano Copyright © 2016 Andrew A. Fanous et al. All rights reserved. Solitary Fibrous Tumor of the Sigmoid Colon Masquerading as an Adnexal Neoplasm Thu, 08 Sep 2016 09:27:21 +0000 Solitary fibrous tumor is a rare, benign spindle cell neoplasm that was first described in the thoracic pleura. This tumor is now known to occur at many extrapleural sites. There are established criteria for the diagnosis of malignant solitary fibrous tumor including ≥4 mitotic figures per 10 high-power fields, increased cellularity, cytologic atypia, infiltrative margins, and/or necrosis. Although all solitary fibrous tumors have the potential to recur or metastasize, those with malignant histologic features tend to behave more aggressively. We report a case of solitary fibrous tumor, with malignant histologic features, in a 21-year-old woman which arose from the serosal surface of the sigmoid colon. Laura Bratton, Rabih Salloum, Wenqing Cao, and Aaron R. Huber Copyright © 2016 Laura Bratton et al. All rights reserved. Lobular Carcinoma of the Breast Metastatic to the Spleen and Accessory Spleen: Report of a Case Thu, 08 Sep 2016 08:15:59 +0000 Despite the fact that accessory spleen (also known as supernumerary spleen, splenunculus, or splenule) can be found in 10–30% of patients undergoing autopsies, metastatic disease occurring in this organ has been barely reported. A case of lobular breast carcinoma metastatic to the spleen and accessory spleen found incidentally at therapeutic splenectomy for severe anemia and thrombocytopenia is described. On microscopic examination both organs revealed severe fibrocongestive changes and extramedullary hematopoiesis with no obvious carcinomatous involvement. Cytokeratin 7, estrogen receptors, and GATA3 immunohistochemistry disclosed the presence of numerous metastatic breast carcinoma cells infiltrating the splenic parenchyma. This case demonstrates that metastatic carcinoma can be encountered, although rarely, in accessory spleens and that cytokeratin stain should be performed in sections of spleens and/or accessory spleens excised from cancer patients in which the presence of malignant epithelial cells is not recognized on routine sections. Gabriel M. Groisman Copyright © 2016 Gabriel M. Groisman. All rights reserved. Cystic and Papillary Neoplasm at the Hepatic Hilum Possibly Originating in the Peribiliary Glands Wed, 31 Aug 2016 16:18:53 +0000 Cystic neoplasms of the liver are divided into two types: mucinous cystic neoplasm and cystic intraductal papillary neoplasm of the bile duct. We herein report two cases of cystic and papillary neoplasm of the liver which differed from the abovementioned types. Case  1. A 70-year-old man. Radiologically, a cystic tumor measuring 20 mm in diameter was found at the hepatic hilum. Right hepatectomy was performed under a diagnosis of intrahepatic cholangiocarcinoma (iCCA) based on the imaging findings. Case  2. A 70-year-old man. Radiologically, a cystic tumor measuring 60 mm in diameter was found at the hepatic hilum. Under a diagnosis of iCCA, left hepatic trisectionectomy was performed. In both cases, endoscopic retrograde cholangiography did not demonstrate communication between the cystic tumor and adjacent bile ducts. Pathologically, these two tumors were cystic neoplasms located at the hepatic hilum and were morphologically characterized by an intracystic papillary neoplasm composed of diffuse high-grade dysplasia and associated with an invasive carcinoma. Ovarian-like stroma was not found in the capsule of these tumors. Interestingly, there were peribiliary glands near these tumors, and MUC6 was expressed in these papillary neoplasms as well as in the peribiliary glands. These neoplasms might have arisen from the peribiliary glands. Takashi Miyata, Katsuhiko Uesaka, and Yasuni Nakanuma Copyright © 2016 Takashi Miyata et al. All rights reserved. Postpartum Granulomatous Hypophysitis: A Case Study, Review of the Literature, and Discussion of Pathogenesis Wed, 24 Aug 2016 18:05:23 +0000 Hypophysitis is a rare inflammatory condition of the pituitary gland that has three main histologic subtypes: lymphocytic hypophysitis (LH), granulomatous hypophysitis (GH), and xanthomatous hypophysitis (XH). Among these, LH is the most common and is strongly associated with the postpartum state, while XH is the least common. Many hypophysitis cases have been reported in the literature but only a few cases of postpartum GH have been discussed. Here, we describe a case of GH in a 24-year-old female presenting eleven days postpartum. We also review the current literature on postpartum GH and discuss the possible alterations in the immune environment during and after pregnancy that could explain this phenomenon. With more cases of GH being reported, the commonalities of female predominance, postpartum time of presentation, and occasional spontaneous resolution between LH and GH lend support to the theory that these two diseases likely represent spectrums of a single immunologic disorder. Upasana Joneja, D. Craig Hooper, James J. Evans, and Mark T. Curtis Copyright © 2016 Upasana Joneja et al. All rights reserved. Unicystic Ameloblastoma with Mural Proliferation Managed by Conservative Treatment Wed, 17 Aug 2016 09:08:43 +0000 Unicystic ameloblastoma is a distinguishable entity of ameloblastomas, characterized by slow growth and being relatively locally aggressive. Three histological types are recognized according to the degree of ameloblastomatous epithelial extension, namely, luminal, intraluminal, and mural types. This classification has a direct bearing on their biological behavior, treatment, and prognosis. However, there is difficulty in determining the most appropriate form of treatment for unicystic ameloblastoma. We present a case of unicystic ameloblastoma that occurred in the right posterior mandible of 19-year-old girl, which was enucleated and did not recur after 12-month follow-up. Natália Galvão Garcia, Denise Tostes Oliveira, and Moacyr Tadeu Vicente Rodrigues Copyright © 2016 Natália Galvão Garcia et al. All rights reserved. Rare Leiomyoma of the Tunica Dartos: A Case Report with Clinical Relevance for Malignant Transformation and HLRCC Wed, 27 Jul 2016 07:00:51 +0000 Background. Genital leiomyomas fall under the broader category of cutaneous leiomyomas, which are rare smooth muscle neoplasms accounting for 5% of all leiomyomas. Genital leiomyomas arising from the dartos muscle are exceedingly rare with fewer than 30 cases reported in the literature. They are typically benign and adequately treated with simple surgical excision; however, previously reported cases of malignant transformation and a possible link to the hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome warrant closer follow-up. Case Presentation. We report a case of a 47-year-old male refugee from Rwanda found to have a mobile, pea-sized, mildly painful scrotal lesion near the left penoscrotal junction and 1.5 cm indeterminate vascular mass in the right kidney. Surgical excision of the scrotal nodule was performed and the diagnosis of a dartoic leiomyoma was rendered. The presence of moderate nuclear atypia, rare mitotic activity, and close surgical margins prompted a wide reexcision. We report the surgical approach, pathologic findings, and clinical follow-up related to this scrotal lesion. Conclusion. Scrotal leiomyomas demonstrate a high rate of recurrence and pose a risk for malignant transformation. They may also indicate an underlying autosomal dominant syndrome associated with increased risk for development of an aggressive form of renal cell carcinoma. When discovered, management should include surgical excision, screening for syndromic features, and routine follow-up. Robert C. Bell, Evan T. Austin, Stacy J. Arnold, Frank C. Lin, Jonathan R. Walker, and Brandon T. Larsen Copyright © 2016 Robert C. Bell et al. All rights reserved. Intraventricular Neurilemmoma (Schwannoma): Shall GFAP Immunostaining Be Regarded as a Histogenetical Tag or as a Mere Histomimetical Trait? Thu, 30 Jun 2016 12:33:16 +0000 Neurilemmomas are benign neoplasms presumedly derived from Schwann cells which rarely originate within the central nervous system. Moreover, their intraventricular location has been seldom noticed with less than 30 cases reported worldwide. Here, we add another case study to the record as well as the fifth one in Latin American population. A 16-year-old boy without significant past clinical data debuted with headache and progressive left eye blindness during six months. Neuroimaging scans showed a bulky, multiloculated, intraventricular tumour emerging from the posterior horn of the left lateral ventricle. Microscopically, the lesion put on view the classical schwannian histology: spindle cells arranged in both compact and loosely textured areas. Verocay bodies were not present but vessel hyalinisation, pericellular reticulin, and senescent atypia were observed. The immunoperoxidase reactions were also consistent with neurilemmal differentiation; however, glial fibrillary acidic protein expression was widespread and unexpectedly seen. Traditionally conceived as “nerve sheath tumours” the dual immunophenotype herein demonstrated points to a different histogenetical pathway other than sheer Schwann cell derivation. As previously advised by some authors, neoplastic transformation from a multipotent stem cell may explain the occasional finding of these tumours in unconventional intracranial compartments. Miguel Fdo. Salazar, Martha Lilia Tena Suck, Daniel Rembao Bojórquez, and Citlaltepetl Salinas Lara Copyright © 2016 Miguel Fdo. Salazar et al. All rights reserved. Intrabiliary Hepatic Metastasis of Colorectal Carcinoma Mimicking Primary Cholangiocarcinoma: A Case Report and Review of the Literature Sun, 26 Jun 2016 10:04:59 +0000 Intrabiliary metastasis from colorectal carcinoma (CRC) growing within or invading bile ducts is not a very common pattern. However, accurate diagnosis of metastatic lesions is very important for selection of adjuvant therapy and prognosis. We report a case of 71-year-old male who developed painless jaundice due to hepatobiliary obstruction. MRI demonstrated 1.4 cm intraductal mass at hepatic hilum with severe intrahepatic ductal dilation, consistent with cholangiocarcinoma. ERCP (endoscopic retrograde cholangiopancreatography) showed intraductal segmental biliary stricture. Biopsy from the lesion showed adenocarcinoma favoring primary cholangiocarcinoma due to the papillary morphology and location of the mass. His past history was significant for rectosigmoid carcinoma (pT1N0) ten years ago and liver resection for metastatic CRC four years ago. He subsequently underwent central hepatectomy with resection of common bile duct. Grossly, there was a 1.2 cm intraductal mass at the bifurcation of bile ducts with multiple nodules in liver parenchyma. Microscopic examination revealed intraductal carcinoma with papillary architecture colonizing bile duct epithelium with resultant dilation and tortuosity. Occasional liver parenchymal nodules show classical metastatic pattern resembling CRC. Because of two distinct morphologic patterns and patient’s past history, immunostains were performed. CK7 stained uninvolved bile duct epithelium with no staining in intrabiliary metastatic growth. CK20 and CDX2 were positive, thus confirming intrabiliary growth as metastatic growth from CRC. In summary, findings from our case indicate that intrabiliary growth of metastatic CRC can easily be overlooked with major duct involvement. Pathologic evaluation with use of immunohistochemical stains is very important to achieve correct diagnosis. Yimin Dong, Hitendra Patel, and Charmi Patel Copyright © 2016 Yimin Dong et al. All rights reserved. A Biphasic Pleural Tumor with Features of an Epithelioid and Small Cell Mesothelioma: Morphologic and Molecular Findings Wed, 15 Jun 2016 09:32:59 +0000 Malignant mesotheliomas are generally classified into epithelioid, sarcomatoid, desmoplastic, and biphasic types with rare reports of a small cell form. These small cell variants display some morphologic overlap with desmoplastic small round cell tumors (DSRCTs) which generally occur within the abdominal cavity of young males and are defined by a characteristic t(11;22)(p13;q12) translocation. However, there are rare reports of DSRCTs lacking this translocation. We present a 78-year-old man with a pleura-based biphasic neoplasm with features of both epithelioid mesothelioma and a small cell blastema-like neoplasm. The epithelioid portion showed IHC reactivity for pan cytokeratin, CK5/6, D2-40, and calretinin and the small cell portion marked with CD99, pan cytokeratin, WT1, FLI1, S100, CD200, MyoD1, and CD15. Fluorescence in situ hybridization testing for the t(11;22)(p13;q12) translocation disclosed loss of the EWSR1 gene in 94% of tumor cell nuclei, but there was no evidence of the classic translocation. Array based-comparative genomic hybridization (a-CGH) confirmed the tumor had numerous chromosome copy number losses, including 11p15.5-p11.12 and 22q12.1-q13.33, with loss of the EWSR1 and WT1 gene regions. Herein, we report novel complex CGH findings in a biphasic tumor and review the molecular genetic alterations in both mesothelioma and DSRCTs. Sarah Hackman, Richard D. Hammer, and Lester Layfield Copyright © 2016 Sarah Hackman et al. All rights reserved. Spinal Intradural, Extramedullary Ependymoma with Astrocytoma Component: A Case Report and Review of the Literature Sun, 29 May 2016 13:39:16 +0000 Ependymomas are common spinal lesions, with the vast majority arising in an intramedullary location. Several cases have been described in the literature of ependymomas in an intradural, extramedullary location. The authors present a case of a 56-year-old female who presented with several weeks of lower back pain and weakness. MRI revealed an intradural, extramedullary enhancing mass at L1-L2. The mass was successfully resected surgically. Pathologic evaluation revealed a low grade glioma with components of both ependymoma and pilocytic astrocytoma with MUTYH G382D mutation. Extramedullary ependymomas are very rare tumors. To the authors’ knowledge, this is the first case of ependymoma/astrocytoma collision tumors described in an extramedullary location. Gene M. Weinstein, Knarik Arkun, James Kryzanski, Michael Lanfranchi, Gaurav K. Gupta, and Harprit Bedi Copyright © 2016 Gene M. Weinstein et al. All rights reserved. Cellular Blue Nevus Diagnosed following Excision of Melanoma: A Challenge in Diagnosis Thu, 26 May 2016 07:51:12 +0000 A case of a 41-year-old woman with a history of nodular melanoma (NM), associated with an indurated dome-shaped blue-black nodule with a diameter of 1.2 cm in the gluteal region, is presented. Clinical diagnosis of the lesion, present from birth, was blue nevus. Recently, the nodule has been showing a mild enlargement and thus complete resection was performed. Histological analysis revealed a pigmented lesion with an expansive pattern of extension into the dermis and the subcutaneous adipose tissue. The lesion displayed an alveolar pattern as well as a pigmented dendritic cell pattern. The histology was consistent with cellular blue nevus (CBN); however, the history of NM which was excised one year earlier, as well as the clinical information about the slow growing lesion, included a differential diagnosis of CBN, borderline melanocytic tumor, and malignant blue nevus. Additional immunohistochemical (HMB-45, p16, and Ki-67) and molecular (BRAF V600E mutation) analyses were performed on both lesions: the CBN-like and the previously excised NM. Along with lesion history and histological analyses, p16 staining and BRAF were useful diagnostic tools for confirming the benign nature of CBN in this case. Nives Jonjić, Andrea Dekanić, Nedeljka Glavan, Larisa Prpić-Massari, and Blaženka Grahovac Copyright © 2016 Nives Jonjić et al. All rights reserved. Short-Spindled Cell Haemangioblastoma with CD34 Expression: New Histopathological Variant or Just a Stochastic Cytological Singularity? Wed, 25 May 2016 11:11:54 +0000 Haemangioblastomas are neoplasms of uncertain histogenesis with cellular and reticular variants advocated in current lore. Herein we describe an intriguing cerebellar specimen with unusual traits including spindle cell morphology and CD34 positivity. A thirty-nine-year old man had an infratentorial tumour discovered incidentally and resected three times. In all the instances, histopathological diagnosis was haemangioblastoma; nonetheless, he had neither physical stigmata nor family history of von Hippel-Lindau disease. By histology, the lesion was composed of areas of conventional stromal cells admixed with territories populated by short-spindled cells packed in lobules, sometimes giving the appearance of gomitoli. Immunoperoxidase-coupled reactions confirmed the expression of inhibin A, neuron-specific enolase (NSE), PS100, and CD57 but also revealed focal immunolabeling for CD34, CD99, and FXIIIa. This case highlights the potential phenotypical diversity that can be found within these neoplasms. Rather than uncertain histogenesis, it may in fact reflect multiple lines of differentiation—histomimesis—prone to adopt unusual morpho- and immunophenotypes in a subset of haemangioblastomas. Miguel Fdo. Salazar, Paola Andrea Escalante Abril, María Verónica Velasco Vales, Celene Martínez Ruiz, Erick Gómez Apo, and Laura G. Chávez Macías Copyright © 2016 Miguel Fdo. Salazar et al. All rights reserved. A Rare Case of Ovarian Filariasis in Abidjan Mon, 23 May 2016 13:44:38 +0000 Ovarian filariasis is an exceptional disease and displays a major diagnostic problem even in endemic areas. We reported the case of a 19-year-old patient who had ovarian cyst which was revealed by chronic pelvic pain. The histological examination of oophorectomy specimen led to the Wuchereria bancrofti filariasis of the ovary. The anatomopathologic examination is required for the diagnosis of this disease. Doukouré Brahima, Abouna Alain Didier, Dou Gonat Serge Pacôme, Aman Nguiessan Alphonse, Koffi Abdoul, and Diomandé Mohenou Isidore Jean-Marie Copyright © 2016 Doukouré Brahima et al. All rights reserved. Diffuse Neuroendocrine Cell Hyperplasia: Report of Two Cases Tue, 17 May 2016 06:44:44 +0000 Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is a rare pulmonary disorder characterised by a proliferation of neuroendocrine cells within the lung. It is believed that a minority of the patients with DIPNECH can develop carcinoid tumors. Here, we report two new cases of DIPNECH with coexisting carcinoid tumors. Cevriye Cansız Ersöz, Ayten Kayı Cangır, and Serpil Dizbay Sak Copyright © 2016 Cevriye Cansız Ersöz et al. All rights reserved. An Unusual Case of Extranodal Diffuse Large B-Cell Lymphoma Infiltrating Skeletal Muscle: A Case Report and Review of the Literature Tue, 10 May 2016 06:15:57 +0000 Diffuse large B-cell lymphoma is extranodal in approximately 40% of cases, arising in nearly any organ system. DLBCL involvement of soft tissue and in particular skeletal muscle is extremely rare, comprising less than 1% of all extranodal non-Hodgkin lymphomas (NHL). We report a case of a 79-year-old man that presented with a DLBCL of the left triceps. In particular, we describe an unusual histologic appearance of pseudoglandular structures, resembling adenocarcinoma. We performed a review of lymphoma cases involving skeletal muscle diagnosed at our institution over the past 15 years as well as thorough PubMed review of the literature. We discuss the features of lymphoma involving skeletal muscle as it pertains to clinical characteristics, histologic subtype, tumor localization, diagnostic studies, therapy, and outcome. Finally, we highlight the diagnostic difficulties that can present in these rare and often challenging cases. Joseph Hatem and Agata M. Bogusz Copyright © 2016 Joseph Hatem and Agata M. Bogusz. All rights reserved. Posterior Mediastinal Adenomatoid Tumor: A Case Report and Review of the Literature Sun, 08 May 2016 14:17:54 +0000 Adenomatoid tumor is an uncommon benign neoplasm of mesothelial differentiation that distinctively arises in and around the genital organs. In rare instances, it has been described in extragenital locations. There have been only two reports documenting its occurrence in the anterior mediastinum, and no reports documenting its occurrence in the posterior mediastinum. We report the first case of posterior mediastinal adenomatoid tumor. A 37-year-old Caucasian woman presented with symptoms of bronchitis. Imaging studies identified a 2.0 cm posterior mediastinal mass abutting the T9 vertebral body, clinically and radiologically most consistent with schwannoma. Histologic sections revealed a lesion composed of epithelioid cells arranged in cords and luminal profiles embedded in a fibrotic to loose stroma and surrounded by a fibrous pseudocapsule. Lesional cells showed vacuolated eosinophilic cytoplasm and peripherally displaced nuclei with prominent nucleoli. There was focal cytologic atypia but no mitotic figures or necrosis was identified. The lesional cells expressed cytokeratin, calretinin, and nuclear WT1 but were negative for PAX8, TTF1, p53, chromogranin, CD31, and CD34, and Ki67 showed <2% proliferation rate, diagnostic of adenomatoid tumor. Three years after resection, the patient is in good health without tumor recurrence. Thus, our encounter effectively expands the differential diagnosis of posterior mediastinal neoplastic entities. Vishwas Parekh, Thomas Winokur, Robert J. Cerfolio, and Todd M. Stevens Copyright © 2016 Vishwas Parekh et al. All rights reserved. Paragonimus kellicotti: A Lung Infection in Our Own Backyard Sun, 24 Apr 2016 11:23:08 +0000 Paragonimiasis is an infection caused by the lung fluke of the genus Paragonimus. Within the United States, paragonimiasis has been commonly diagnosed in Southeast Asian immigrants infected with the Asian lung fluke Paragonimus westermani. Infections from the North American lung fluke, Paragonimus kellicotti, have been rare, although more infections have been seen in people in the Midwestern United States. A 29-year-old male with a history of pleomorphic xanthoastrocytoma presented with hemoptysis. A CT scan showed a mass in the left upper lung lobe. A biopsy showed eosinophils and parasite eggs, some with a recognizable operculum. Further investigation revealed that he takes canoe trips on rivers within Missouri and would eat crayfish caught from these rivers. A blood sample was confirmed positive for Paragonimiasis serologically at the Center for Disease Control. Paragonimus kellicotti is found in rivers within the Mississippi basin. Infection occurs by consuming uncooked or undercooked crawfish. Microscopic identification of parasite eggs has been the gold standard. Serologic tests have been developed to aid in the diagnosis. Patients typically present with fever and hemoptysis. Common CT findings include pleural effusion, a mass, and lymphadenopathy. Awareness of P. kellicotti is important to guide appropriate diagnostic testing and ensuring proper treatment. Eric Johannesen and Van Nguyen Copyright © 2016 Eric Johannesen and Van Nguyen. All rights reserved. From the Gut to the Liver: Another Organ to Watch in FAP Patients Thu, 24 Mar 2016 11:13:07 +0000 We report a rare association of hepatocellular carcinoma with familial adenomatous polyposis in a young patient and its clinical significance. A 28-year-old female with a past medical history of familial adenomatous polyposis (FAP) and subsequent colonic adenocarcinoma underwent total colectomy. She later presented with intermittent right upper quadrant pain and nausea of four months’ duration. MRI of the abdomen revealed multiple liver lesions, the largest 8.5 cm in diameter, with radiologic features suggestive of hepatocellular carcinoma. A CT-guided liver biopsy demonstrated well-differentiated HCC which was confirmed by immunohistochemistry. In patients with a history of FAP, a heightened awareness of the possibility of concurrent or subsequent HCC is warranted. Spencer Paulson, Charmi Patel, and Hitendra Patel Copyright © 2016 Spencer Paulson et al. All rights reserved.