Human chorionic gonadotropin-secreting clear cell renal cell carcinoma with paraneoplastic gynaecomastia.

A 60-year-man presented with painful gynaecomastia and polycythaemia due to a beta-human chorionic gonadotropin (HCG)-secreting clear cell renal cell carcinoma. A computed tomographic scan of his chest, abdomen and pelvis showed an enhancing 9x9 cm mass in the right kidney suggestive of a renal cell carcinoma. He underwent right radical nephrectomy and the histology showed a clear cell renal cell carcinoma. Following his nephrectomy, over the next 6 months, his gynaecomastia regressed and serum beta-HCG levels became undetectable. Nine months after his nephrectomy, he developed a paratesticular lesion involving scrotal skin, for which he underwent a right radical orchidectomy. Histopathology of the paratesticular lesion showed metastatic renal cell carcinoma.