Prostatic Adenocarcinoma Metastatic to Pleomorphic Liposarcoma, a “Collision Phenomenon”: Report of a Case with Review of Pelvic Collision Tumors

Table 2

Sequence of events.

Year	Site	Morphology	IHC	FISH	Diagnosis	Treatment
5/2003	Urinary bladder diverticulum	Biphasic (epithelial and spindle cells) tumor with high-grade cytologic features. ALI−, PNI−, perivesical soft-tissue invasion	panCK+, CK20+, Vimentin−, CD68−, desmin−, SMA−	NA	Sarcomatoid urothelial carcinoma	Partial cystectomy, gemcitabine and carboplatin (4 cycles), intravesical BCG
10/2006	Prostate	Prostate adenocarcinoma, Gleason’s Score 4+4=8, ALI+, PNI+, ECE+, Seminal vesicle involvement.	NA	NA	High-grade prostatic adenocarcinoma	Radical prostatectomy and radiotherapy
4/2010	Pelvic mass	Myxoid liposarcoma with pleomorphic areas, characteristic lipoblasts and hyalinized stroma mingled with well-differentiated prostatic adenocarcinoma	Liposarcoma: vimentin+, S100−, SMA−, desmin−, HMB45−, melan A−, myogenin−, CD117−; PCa: AE1/AE3+, CAM5.2+, weak P501S+, AR+	Liposarcoma: CHOP+, MDM2−; PCa:TMPRSS2−; ERG+	Dedifferentiated myxoid liposarcoma with embedded prostatic adenocarcinoma	Tumor resection, en bloc sigmoid colectomy, and ureteroneocystostomy

ALI: angiolymphatic invasion, AR: androgen receptor, CK: Cytokeratin, ECE: extracapsular extension, FISH: florescence in situ hybridization, IHC: immunohistochemistry, PCa: prostatic adenocarcinoma: PNI: perineural invasion, SMA: smooth muscle actin.