Hepatoid adenocarcinoma of the urinary bladder. An unusual neoplasm

A new case of hepatoid adenocarcinoma was diagnosed in fragments obtained at transurethral resection (TUR) from a 71-year-old man who had complained of haematuria. The tumour was composed of trabeculae and small solid nests of polygonal atypical cells simulating hepatocarcinoma, together with glandular areas of an otherwise typical adenocarcinoma. Immunohistochemistry showed cytoplasmic reactivity to AFP, AAT, albumin and CAM 5.2. Membrane reactivity was seen in EMA immunostaining, and there was also positivity to polyclonal CEA following a canalicular pattern. Immunoperoxidase studies of hepatocyte growth factor (HGF) and its receptor, c-met, were positive. Their expression may be related to the aggressive behaviour of this tumour.