[P-21] Clear cell adenocarcinoma of bladder – a case with evidence of müllerianosis

Varuni Fernando, Gerhard Van Schalkwyk, Nirav Gandhi and Manuel Diaz Sotres

Department of Pathology, University Hospital of Derby and Burton, United Kingdom

Background: Clear cell adenocarcinoma of bladder is rare with only few cases showing Müllerianosis, its presumed aetiology. We describe such a case, suspected at biopsy and showing endometriosis.

Case Presentation: A 45-year-old female presented with haematuria and cystoscopy revealed a 45 mm bladder tumour. She had no past malignancies. Biopsy showed a clear cell tumour with positive CK7, PAX 8, Napsin A; negative CK20 and ER with deep muscle invasion. A diagnosis of clear cell adenocarcinoma (mesonephric type as formerly known) was suggested. Patient underwent anterior exenteration. Microscopy showed tubulopapillary, high grade, clear cell morphology. Tumour invaded peri vesical fat but not cervical stroma. It showed positive PAX 8, CK 7, patchy Napsin A, CA 125 and racemase and negative p63, CK 20 and ER. Lymphovascular invasion, margin involvement and lymph nodes metastasis were negative. Bladder endometriosis and a mucinous cystadenoma of ovary was present. No conventional urothelial carcinoma (UC), dysplasia or a clear cell carcinoma of gynae tract was present. Peritoneal fluid cytology was negative.

Discussion and Conclusion: The presumed aetiology of müllerianosis was present in our case as endometriosis (a component of Müllerianosis) while this was rarely reported in literature. Conventional UC reported in some cases as an aetiology was not seen in ours. Racemase positivity, shown to help in distinction from differentials in most cases was seen in ours. Only few reported cases showed biopsy diagnosis. A strong suspicion of this entity especially in a female and favourable immunostains supported our biopsy diagnosis.