[A CASE OF PROSTATE CANCER WITH SECONDARY HYPOGONADISM].

A 70 year-old man underwent contrast CT, which revealed his swollen left inguinal and pelvic lymph nodes. The lymph nodes reduced in size without any treatments in a follow-up examination. In 2013, the lymph nodes enlarged again, and FDG-PET/CT showed high value at the prostate and multiple lymph nodes. The levels of serum PSA was high (PSA=682 ng/ml), therefore he underwent a prostate biopsy in his previous hospital and was diagnosed prostate cancer with metastasis of lymph nodes (cT2cN1M1a). Androgen deprivation therapy (ADT) was administered; however, the levels of serum PSA didn't reduce and lymph nodes enlarged further. He was referred to our hospital for further evaluation and treatment. The levels of serum total testosterone before ADT administration at his previous hospital was less than 0.05 ng/ml, which meaned that he had been hypogonadism. Brain MRI revealed a pituitary tumor, and he was diagnosed secondary hypogonadism due to the pituitary tumor. This was thought a rare case of a prostate cancer with secondary hypogonadism which had become castration resistant at the time of diagnosis.