Clinical evidence of neuroendocrine differentiation in a patient with prostate cancer and bone marrow micrometastases.

A 58-year-old man had a biopsy taken in November 1998 and was diagnosed as having prostatic adenocarcinoma of Gleason score 5 (3+2); his serum PSA was 86.7 ng/mL. A DRE revealed a palpable nodule of increased consistency on the left lobe of the prostate; TRUS showed a hypoechoic area 1.5 cm in diameter in the peripheral zone of the left lobe of the prostate, with no evidence of capsular or seminal vesicle in®ltration. CT of the abdomen and pelvis showed no lymphadenopathy, and the bone scan and chest X-rays were normal. Laboratory tests showed a signi®cant reduction in haemoglobin (94 g/L, normal 132±170), platelet count (89 000; normal 150 000±450 000) and neutrophils (33.8%, normal 55±70). In November 1998 the patient underwent an iliac bone marrow biopsy and the histology showed tumour cell clusters; immunohistochemical staining for PSA was positive at the tumour cell sites. Histological sections from the prostate biopsy were assessed for chromogranin A expression by immunohistochemistry [1], and more than one focus with extensive staining for chromogranin A was detectable in the tumour cells (.Fig. 1). Moreover, high