Usefulness of positron emission tomography (PET) in a retroperitoneal primary non-seminomatous germ cell tumor: a case report

Abstract

A 32-year-old Japanese man was admitted complaining of palindromic fever and abdominal pain. Computed tomography (CT) revealed retroperitoneal mass and positron emission tomography (PET) demonstrated massive radiotracer uptake in this tumor. Serum levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) were 4, 760 ng/ml, 6, 000 mIU/ml, respectively. Biopsy specimen from the tumor showed non-seminomatous germ cell tumor. The International Germ Cell Cancer Collaborative Group (IGCCCG) staging system indicated this case as an intermediate prognosis group. After three cycles of bleomycin, etoposide and cisplatin (BEP) therapy, CT revealed a degenerated residual mass. Serum levels of tumor markers were normalized completely and PET showed no radiotracer uptake in the retroperitoneal lesion. Although he did not receive further chemotherapy and lymph nodes were not dissected, he was free of disease for two years.

症例は間欠的な発熱および腹痛を主訴として入院した32歳, 男性.CT上, 後腹膜リンパ節の腫大が指摘され, PETにて同部位に著明な集積を認めた.血清AFP, hCGはそれぞれ4, 760ng/ml, 6, 000IU/mlと上昇していた.開腹後腹膜リンパ節生検により非セミノーマ性胚細胞腫瘍が検出された.IGCCCG分類ではintermediate prognosis groupであった.3コースのBEP療法により縮小した残存腫瘍が認められるのみとなった.腫瘍マーカー値はいずれも正常化しPETでは後腹膜領域に集積を認めなくなった.4コース目の化学療法や後腹膜リンパ節郭清術を行わず経過を観察したところ, 現在まで2年の無再発期間を得ている(著者抄録)