Gliomatosis peritonei with 18F-fluorodeoxyglucose accumulation and contrast enhancement secondary to immature teratoma: A case report.

Gliomatosis peritonei (GP) is a rare condition characterized by mature glial tissue implants widespread in the peritoneum, which is occasionally followed by treatment for immature teratoma (IM). The present study reported a case of GP with fluorodeoxyglucose (FDG) accumulation and contrast enhancement followed by treatment for IM. A 30-year-old female, 2-gravida and 0-para, underwent laparotomy with hysterectomy, bilateral salpingo-oophorectomy, and partial omentectomy followed by four cycles of chemotherapy with bleomycin, etoposide, and cisplatin for IM (Grade 2) of stage IIIC. At the 6-month follow-up, computed tomography (CT) revealed a 1-cm mass with contrast enhancement on splenic flexure. Positron-emission tomography (PET)/CT revealed intense FDG accumulation at the same site. Although α-fetoprotein, which was elevated preoperatively, remained normal, she was diagnosed with IM recurrence. The patient underwent three cycles of chemotherapy with paclitaxel, ifosfamide, and cisplatin, but the size, the degree of contrast enhancement and FDG accumulation of the mass did not change after chemotherapy. A diagnostic laparoscopy was performed. which revealed multiple small peritoneal implants, including a 1-cm mass at the splenic flexure. The 1-cm mass was dissected at the splenic flexure and some other implants. Mature well-differentiated glial tissue with non-atypia was identified in all tissue, and a diagnosis of GP was made. The patient is currently undergoing regular follow-up. Few reports are available regarding FDG-PET/CT imaging of GP. GP should be considered as the differential diagnosis of FDG-avid mass followed by IM therapy. A laparoscopic diagnosis is useful to obtain an accurate diagnosis of GP.