ホルモン療法中にNeuroendocrine differentiationをきたした前立腺癌の1例

Abstract

80歳男性.患者は排尿困難, 夜間頻尿で受診となった.PSAの高値から前立腺針生検, 諸検査で中分化型腺癌 stage D2(骨転移)と診断し, MAB療法を開始した.PSAは低下し, MRIで前立腺容積の縮小を認めた.約2年後PSAは低値であったが, CEAの上昇からMRIで前立腺右葉に6cmの腫瘍を認め, 精嚢右葉に浸潤し直腸を圧排しており, 右内腸骨リンパ節腫脹を認めた.生検では低分化型腺癌で, 免疫染色では初回に陰性であったCEA, NSE, chromogranin A, synaptophysin, NCAM染色が全て陽性となっていた.CTでは肺・肝転移などは認めなかったが, 約7ヵ月後にはCEA, NSEはさらに上昇し, CTでは多発肺転移を認め, 疼痛管理中心のQOL重視の治療を行ったが死亡した

Neuroendocrine (NE) cells are widely distributed in the acini and ducts of the normal prostate gland and produce neurosecretory products, which affect growth, differentiation and regulation of secretory function. Prostatic NE carcinoma is a rare situation and the NE differentiation in prostate adenocarcinoma appears to be characterized by poor prognosis, rapid tumor progression and the androgen-independent state, for which there is currently no successful therapy. We report a case of NE differentiated prostatic carcinoma, which was diagnosed as adenocarcinoma initially and the tumor progressed rapidly with NE differentiation during androgen suppression therapy.