title: Primary choriocarcinoma of the bladder evolving from a transitional cell carcinoma.
abstract: A 67 year old man presented with haematuria, which on investigation was shown to be derived from a bladder tumour. The tumour initially was a typical transitional cell carcinoma except for rare trophoblastic cells. Over the next year and a half it gradually evolved into a choriocarcinoma. Postmortem examination confirmed that this was a primary choriocarcinoma of the bladder with no other sites of derivation shown.
mesh_terms: D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D002822:Choriocarcinoma / Q000473:pathology*; D006801:Humans; D008297:Male; D009378:Neoplasms, Multiple Primary / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000473:pathology*