Increased 18F-FDG Uptake by a Retroperitoneal Mature Cystic Teratoma in an Infant

Abstract

A teratoma is a nonseminomatous germ cell tumor composed of well-differentiated derivations from at least 2 of the 3 germ layers. Mature cystic teratomas are known to have low metabolic activity and do not exhibit increased FDG uptake on PET. We report a case of mature cystic teratoma of the retroperitoneum showing increased FDG uptake in the solid portion. Pathologically, the solid portion was composed of abundant central nervous tissue. Increased FDG uptake in a teratoma may be not only due to an immature or malignant component but also to the presence of central nervous tissue.

Alpha-fetoprotein-elevated postpubertal testicular teratoma with retroperitoneal metastasis on 18F-FDG PET/CT: case report and literature review

“…A literature search was performed on the PubMed and database from 1997 to 2022, using the keyword “retroperitoneal teratoma” and “PET/CT.” There were night cases of retroperitoneal teratoma with PET/CT findings. The basic information and metabolism of retroperitoneal teratoma are summarized in Table 1 ( 15 , 24–29 ). Out of these night cases, only one patient was 7 months old, while other patients were adults, ranging in age from 23 to 49 years, with more males than females.…”

“…When the tumor was a pure mature teratoma, there was usually no increased FDG uptake or slightly increased FDG uptake, which was consistent with previous findings that mature teratomas had a very low avidity for 18 F-FDG, with a SUVmean of 1.38 ( 7 , 8 ). However, one infant with a mature teratoma had a SUVmax of 4.1, possibly due to the abundant central nervous tissue ( 24 ). In addition to this, if mature teratomas showed increased FDG uptake, possibly due to the presence of immature teratoma, embryonal carcinoma, or malignant somatic tissue components.…”

The Role of Postchemotherapy Surgery in Germ Cell Tumors

“…Teratoma can be FDG PET avid, giving the same appearance as viable tumor. 26 The vast majority of teratoma is not FDG PET avid, however, and thus a negative FDG PET does not exclude the presence of teratoma in postchemotherapy NSGCT masses. 27 The largest study to date examining FDG PET in NSGCT comes from the German Multicenter PET Study Group.…”

Ovarian Hyperstimulation and Oocyte Harvesting Prior to Systemic Chemotherapy—A Possible Pitfall in 18F-FDG PET/CT Staging of Oncologic Patients

“…6,7 Other differential diagnoses for FDG-avid ovarian lesions are endometrioma, primary and secondary ovarian malignancy, and corpus luteum cyst. [8][9][10][11][12][13][14][15][16][17] FIGURE 1. An initial CT scan 3 weeks before the FDG PET/CT scan showed no subdiaphragmal lymphoma manifestation, ascites, or pelvic mass.…”