傍直腸腔原発の悪性リンパ腫の1例

Abstract

16歳男子.主訴は腰痛, 肛門痛, 排便障害.腹骨盤部CTでは左水腎症, 軽度の肝脾腫を認め骨盤内に9×6cmの境界不明瞭な腫瘤を認めた.骨盤部MRIでは直腸の右腹側, 前立腺の頭側にT1で等信号, T2で低信号の腫瘤を認め精嚢は不明瞭であった.骨盤内腫瘤に対して経直腸的腫瘤生検術を施行した.諸検査より臨床病期II EAXの小骨盤内原発の悪性リンパ腫と診断し, 血液膠原病科に転科しCHOP療法を開始した.化学療法開始直後より症状は著明に改善, クレアチニン, LDHとも正常化し, 左水腎症も消失した.当初小骨盤内と判断した原発部位は治療中の縮小した腫瘍の位置より傍直腸腔と診断された

A 16-year-old man presented with lumbago, perianal pain and constipation. A large tumor was palpable by digital rectal examination. Then, transrectal needle biopsies of the tumor were performed. Histopathological diagnosis was non-Hodgkin's malignant lymphoma (diffuse large B-cell type according to the new WHO classification). The results of some examinations were compatible with the diagnosis of primary lymphoma of the pararectal space. The patient underwent 2 courses of combination chemotherapy CHOP (consisting of cyclophosphamide, doxorubichin, vincristine, and prednisolone), and high-dose chemotherapy (ranimustine, etoposide, ifosfamide) with peripheral blood stem cell transplantation. After high-dose chemotherapy, radiation therapy was performed since there was a possibility of residual tumor, and complete remission was achieved. Now, 12 months after completion of the radiation, he remains free of the disease. This is probably the first clinical case of malignant lymphoma of the pararectal space ever reported in the Japanese literature.