Table of Contents Author Guidelines Submit a Manuscript
Case Reports in Obstetrics and Gynecology
Volume 2015, Article ID 687183, 3 pages
Case Report

Multicystic Benign Mesothelioma Complicating Pregnancy

Department of Obstetrics and Gynaecology, Jessop Wing, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield S10 2SF, UK

Received 30 May 2015; Accepted 28 July 2015

Academic Editor: Maria Grazia Porpora

Copyright © 2015 V. A. Tamhankar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Multicystic benign mesothelioma (MBM) is a rare peritoneal pathology typically affecting women in reproductive age. Though MBM is considered benign, these lesions are prone to recurrence and their growth could be modulated by the presence of oestrogen receptors. Acute presentation of MBM is still very rare in pregnancy and management options are not established. We describe a case of MBM presenting in early pregnancy with acute pain. This was successfully treated with surgical resection. Pregnancy continued uneventfully to term and no evidence of recurrent MBM was found at Caesarean section.

1. Introduction

Multicystic benign mesothelioma (MBM) is a rare pathology typically presenting as cystic lesions in the peritoneal cavity [14]. These cysts originate from the peritoneal mesothelium. The disease predominantly occurs in women in their reproductive age but rare cases have been described in men [3, 5, 6]. The aetiology of the disease is ill-understood. Some consider it to be a reactive process secondary to previous surgical trauma or inflammation causing peritoneal inclusion cysts [4, 7]. Others have considered a neoplastic aetiology particularly with the associated risk of recurrence after resection [1, 3, 811]. Sawh et al. have shown that a proportion of MBM are oestrogen receptor carriers and hence their growth and progress may be dependent on hormonal influence [2]. Such hormone sensitivity of MBM has been targeted as a therapeutic option with some success [12, 13].

MBM remains a poorly understood condition with less than 150 reported cases. Most of the data comes from isolated case reports and short case series. Though this condition predominantly affects women in reproductive age, not a lot is known about its course and management in pregnancy. On review of literature, we found only five reported cases of MBM complicating pregnancy [1317]. In four of them, MBM was found as an asymptomatic or incidental diagnosis and the fifth case was treated with termination of pregnancy and tamoxifen.

We present a case of MBM who presented with acute pain in early pregnancy and was treated successfully with surgical resection.

2. Case Report

A 23-year-old nulliparous woman presented at seven weeks of gestation with right iliac fossa pain. She had previous history of appendicectomy but no other known comorbidities except for obesity. Inflammatory blood markers were normal. An ultrasound scan confirmed a viable intrauterine pregnancy, a normal left ovary, and a 6.4 cm × 4 cm multiloculated cystic mass in the pelvis (Figure 1). The right ovary was not visualised separately. The differential diagnoses of a cystic right ovarian mass or MBM were considered. As the initial acute symptoms settled with analgesia, a decision was made to continue expectant treatment in the first trimester. The patient however returned six weeks later with increasing pain. Examination revealed localised peritonitis with tenderness and guarding in the right iliac fossa. A repeat ultrasound scan revealed an increased size of the existing multicystic mass (13 cm × 7 cm). Due to increasing pain, presence of peritoneal signs in the right iliac fossa, and uncertain nature of this cystic mass a decision was made to surgically remove this mass. An exploratory laparotomy was performed at 14 weeks of gestation. The multicystic mass was seen adherent to the pelvic peritoneum and was free from both ovaries, which were normal. There was no evidence of any other inflammatory bowel pathology, pelvic haemoserous fluid, or rupture of the cystic lesion. The lesion was excised (Figure 2) and histology confirmed the diagnosis of MBM. No antibiotics were given postoperatively. The patient recovered from the procedure and continued with the pregnancy uneventfully. She eventually underwent an emergency Caesarean section at term due to failure to progress in labour. At delivery there was no recurrence of the previously noted peritoneal cysts.

Figure 1: Ultrasound scan image of pelvic multicystic mass.
Figure 2: Excised multiloculated cyst with translucent fluid and peritoneal connections.

3. Discussion

MBM is a rare pathology and difficult to diagnose preoperatively. Ultrasound scan, magnetic resonance imaging, and computerised tomography have been used to identify multicystic lesions without adjacent organ invasion or lymphadenopathy. Histological confirmation depends on finding thin walled cysts lined by simple cuboidal or flattened epithelial cells which stain positive for calretinin, a marker of mesothelial origin [2].

MBM is commonly found as an incidental diagnosis or presents with chronic dull pain or mass. Finding MBM cysts in the pelvis along with an intrauterine pregnancy on ultrasound scan does pose a clinical difficulty. It is impossible to predict if the MBM lesions will progress and grow rapidly during pregnancy or will become symptomatic. If the patient presents with acute pain and peritonitis like in our case the decision of surgical resection is easy to make. Though surgical intervention during pregnancy carries some added risk of miscarriage, our patient made a good recovery and completed a full term pregnancy.

The diagnosis of MBM during pregnancy has been reported in five individual patients so far. In three patients, these cysts have been found incidentally at the time of full term Caesarean sections [14, 15, 17]. These patients remained asymptomatic and the pregnancies proceeded uneventfully. van Bijsterveldt et al. describe pregnancy in a patient who had long-standing MBM, previously confirmed on partial resection [16]. This patient had two separate pregnancies, both uneventful and full term, with no change in the MBM on MRI scan. This patient later required further surgical excision, four years after the second delivery, which reconfirmed the diagnosis of MBM. Data from these four patients and their five pregnancies suggest that MBM usually remains asymptomatic and is an incidental diagnosis during pregnancy. Hence an expectant treatment should be offered.

The fifth case report described a patient presenting with acute pain at five weeks of intrauterine gestation and ultrasound diagnosis of pelvic MBM [13]. This was treated with laparotomy and excision. Histology confirmed the diagnosis of MBM with positive oestrogen receptors. The pelvic MBM recurred and was confirmed 6 weeks after initial resection on ultrasound scan. This patient was then offered termination of pregnancy and treated with tamoxifen. MBM remained stable while on tamoxifen treatment.

Study by Sawh et al. has shown that, though uncommon, MBM can be oestrogen receptor positive [2]. In their study only two of the fourteen patients tested positive for oestrogen receptors. We did not study the oestrogen receptors on the resected histology specimen in our patient. Oestrogen receptor positivity will have an impact on the growth and recurrence risk of such MBM in the hyperoestrogenic state of pregnancy as shown by Jerbi et al. [13]. Recurrence rate after MBM resection remains high between 40 and 50% [2, 6, 7, 11, 18]. Clearly in appropriately selected cases tamoxifen does have a therapeutic role [12, 13].

Our above review demonstrates that asymptomatic MBM can be treated expectantly during pregnancy. However it needs to be differentiated from the malignant pelvic cystic tumours. Contrast enhanced and diffusion weighted magnetic resonance imaging has been shown to be useful in predicting the malignant nature of such cystic lesions [19, 20]. Such imaging would be mandatory if a conservative approach is chosen.

Our case is distinct and adds to existing literature as we have demonstrated successful surgical treatment of symptomatic MBM whilst preserving pregnancy. In their review, van Ruth et al. conclude that completeness of resection predicts recurrence risk [21]. We do believe that macroscopic and microscopic completeness of resection reduces the risk of recurrence and hence recommend surgical treatment in appropriately selected cases.

Conflict of Interests

The author declares that there is no conflict of interests.


  1. R. Mennemeyer and M. Smith, “Multicystic, peritoneal mesothelioma: a report with electron microscopy of a case mimicking intra-abdominal cystic hygroma (lymphangioma),” Cancer, vol. 44, no. 2, pp. 692–698, 1979. View at Google Scholar · View at Scopus
  2. R. N. Sawh, A. Malpica, M. T. Deavers, J. Liu, and E. G. Silva, “Benign cystic mesothelioma of the peritoneum: a clinicopathologic study of 17 cases and immunohistochemical analysis of estrogen and progesterone receptor status,” Human Pathology, vol. 34, no. 4, pp. 369–374, 2003. View at Publisher · View at Google Scholar · View at Scopus
  3. S. W. Weiss and F. A. Tavassoli, “Multicystic mesothelioma. An analysis of pathologic findings and biologic behavior in 37 cases,” The American Journal of Surgical Pathology, vol. 12, no. 10, pp. 737–746, 1988. View at Publisher · View at Google Scholar · View at Scopus
  4. K. Sethna, F. Mohamed, P. Marchettini, D. Elias, and P. H. Sugarbaker, “Peritoneal cystic mesothelioma: a case series,” Tumori, vol. 89, no. 1, pp. 31–35, 2003. View at Google Scholar · View at Scopus
  5. J. H. Moore Jr., C. P. Crum, J. G. Chandler, and P. S. Feldman, “Benign cystic mesothelioma,” Cancer, vol. 45, no. 9, pp. 2395–2399, 1980. View at Publisher · View at Google Scholar · View at Scopus
  6. H. A. Carpenter, J. R. Lancaster, and R. A. Lee, “Multilocular cysts of the peritoneum,” Mayo Clinic Proceedings, vol. 57, no. 10, pp. 634–638, 1982. View at Google Scholar · View at Scopus
  7. M. J. Ross, W. R. Welch, and R. E. Scully, “Multiocular peritoneal inclusion cysts (so-called cystic mesotheliomas),” Cancer, vol. 64, no. 6, pp. 1336–1346, 1989. View at Google Scholar · View at Scopus
  8. L. Scucchi, P. Mingazzini, D. Di Stefano, M. Falchi, A. Camilli, and A. Vecchione, “Two cases of ‘Multicystic peritoneal mesothelioma’: description and critical review of the literature,” Anticancer Research, vol. 14, no. 2B, pp. 715–720, 1994. View at Google Scholar · View at Scopus
  9. P. Cusatelli, G. Altavilla, and M. Marchetti, “Benign cystic mesothelioma of peritoneum: a case report,” European Journal of Gynaecological Oncology, vol. 18, no. 2, pp. 124–126, 1997. View at Google Scholar · View at Scopus
  10. S. González-Moreno, H. Yan, K. W. Alcorn, and P. H. Sugarbaker, “Malignant transformation of ‘Benign’ cystic mesothelioma of the peritoneum,” Journal of Surgical Oncology, vol. 79, no. 4, pp. 243–251, 2002. View at Publisher · View at Google Scholar · View at Scopus
  11. Y. Katsube, K. Mukai, and S. G. Silverberg, “Cystic mesothelioma of the peritoneum. A report of five cases and review of the literature,” Cancer, vol. 50, no. 8, pp. 1615–1622, 1982. View at Publisher · View at Google Scholar · View at Scopus
  12. G. S. Letterie and J. L. Yon, “The antiestrogen tamoxifen in the treatment of recurrent benign cystic mesothelioma,” Gynecologic Oncology, vol. 70, no. 1, pp. 131–133, 1998. View at Publisher · View at Google Scholar · View at Scopus
  13. M. Jerbi, S. Hidar, S. Ziadi, and H. Khairi, “Benign multicystic peritoneal mesothelioma,” International Journal of Gynecology and Obstetrics, vol. 93, no. 3, pp. 267–268, 2006. View at Publisher · View at Google Scholar · View at Scopus
  14. S. Nayak, R. C. Parate, and S. Bobhate, “Multilocular peritoneal inclusion cyst—a case report,” Indian Journal of Pathology and Microbiology, vol. 48, no. 2, pp. 247–249, 2005. View at Google Scholar · View at Scopus
  15. O. Akbayir, A. Gedikbasi, A. Akyol, C. Numanoglu, N. Koroglu, and A. Gulkilik, “Benign cystic mesothelioma: a case series with one case complicated by pregnancy,” Journal of Obstetrics and Gynaecology Research, vol. 37, no. 8, pp. 1126–1131, 2011. View at Publisher · View at Google Scholar · View at Scopus
  16. C. van Bijsterveldt, J. Bulten, and W. Willemsen, “Peritoneal benign mesothelioma during and after two pregnancies,” European Journal of Obstetrics & Gynecology and Reproductive Biology, vol. 127, no. 2, pp. 265–266, 2006. View at Publisher · View at Google Scholar · View at Scopus
  17. H. I. Watson, M. Borovickova, and A. Shetty, “The curious case of free-floating pelvic cysts,” BMJ Case Reports, 2014. View at Publisher · View at Google Scholar · View at Scopus
  18. J. D. O'Neil, P. R. Ros, B. L. Strom, J. L. Buck, and E. J. Wilkinson, “Cystic mesothelioma of the peritoneum,” Radiology, vol. 170, no. 2, pp. 333–337, 1989. View at Publisher · View at Google Scholar · View at Scopus
  19. E. Sala, A. Rockall, D. Rangarajan, and R. A. Kubik-Huch, “The role of dynamic contrast-enhanced and diffusion weighted magnetic resonance imaging in the female pelvis,” European Journal of Radiology, vol. 76, no. 3, pp. 367–385, 2010. View at Publisher · View at Google Scholar · View at Scopus
  20. R. N. Low and R. M. Barone, “Combined diffusion-weighted and gadolinium-enhanced MRI can accurately predict the peritoneal cancer index preoperatively in patients being considered for cytoreductive surgical procedures,” Annals of Surgical Oncology, vol. 19, no. 5, pp. 1394–1401, 2012. View at Publisher · View at Google Scholar · View at Scopus
  21. S. van Ruth, M. W. G. A. Bronkhorst, F. van Coevorden, and F. A. N. Zoetmulder, “Peritoneal benign cystic mesothelioma: a case report and review of the literature,” European Journal of Surgical Oncology, vol. 28, no. 2, pp. 192–195, 2002. View at Publisher · View at Google Scholar