Somatic malignant transformation in a sacrococcygeal teratoma in a child and the use of F18FDG PET imaging

Abstract

A 6-year-old female presented with a subcutaneous sacral mass. Biopsy revealed an adenocarcinoma most likely arising from a sacrococcygeal teratoma (SCT). CT imaging revealed a massive tumour consistent with SCT. F(18)FDG Positron Emission Tomography (PET) scan confirmed marked metabolic activity in the tumour mass and regional lymph node involvement. After chemotherapy repeat CT and PET studies revealed a poor response but no evidence of peritoneal or distant metastases. Radical abdomino-pelvic and gluteal surgery was performed with removal of the entire tumour confirmed as a moderately differentiated adenocarcinoma arising in an immature teratoma. Follow up imaging including PET scanning 5 months after her surgery revealed widespread peritoneal, hepatic and pulmonary metastases. Somatic malignant transformation of an SCT in a child of this age has not been previously reported.

Early experience with PET/CT scan in the evaluation of pediatric abdominal neoplasms

“…To date, this has been limited to single case reports [6][7][8], with no large series reported. The FDG avidity was demonstrated in all abdominal tumors, making it a very sensitive diagnostic modality.…”

Long-term outcomes of surgery for malignant sacrococcygeal teratoma: 20-year experience of a regional UK centre

“…However, computerized tomography scans may be important in children who have large midline abscesses because these may actually be SCT as in one of our cases who had an abscess incised twice prior to diagnosis. Recently, the use of positron emission tomography (PET) scan has been found to be useful in the diagnosis and follow-up of malignant SCT patients [7]. Tumour recurrence does have a bad prognosis.…”

Morphological spectrum and molecular features of somatic malignant transformation in germ cell tumours

“…The clinical decision of continuing with chemotherapy directed at the GCT component or at the SMT component is challenging and decided on a case-by-case basis, with different outcomes from series to series. 14,[41][42][43] Additional levels of complexity in this decision include the context of paediatric cancers, 41,44 SMT arising in ovarian GCTs, 45 and in extragonadal locations, [46][47][48][49][50] which are rarer but may have their own specificities.…”