A Rare Case of Pelvic Primitive Neuroectodermal Tumor in a 37-Year-Old Patient

Abstract

Primitive neuroectodermal tumors (PNETs) belong to the group of malignant bone tumors. Their frequency is about 1% of sarcoma. The principal distinctive feature is a translocation concerning the EWS gene or t(11;22)(q24; q12). They are even rarer when located in the extra-skeletal pelvic region. We report a case of a 37-year-old female patient with a PNET in the pelvic region that is found after a spontaneous abortion. The tumor is localized on the right latero-uterine ligament. The tumoral size is of 10 cm. After the coelioscopic diagnosis, the patient was treated with neo-adjuvant chemotherapy according to vincristine, ifosfamide, doxorubicin, and etoposide (VIDE) protocol, which ensured an important diminishing of the size of the tumor. She then had a total radical hysterectomy associated with a lymph node resection. The diagnosis was confirmed by histology, immunohistology examinations and molecular biology by hybridization in situ . The tumoral cells were classically small and round. They expressed CD99 and vimentin. Translocation t(11;12)(q24;q12) was positive. Two months later, the patient presented a tumoral relapse and received an adjuvant chemotherapy by vincristine, dactinomycin, and ifosfamide (VAI) twice with a limited chemical and hematological tolerance that brought along palliative treatment. Extra-skeletal PNETs found in the pelvic region are very rare. Our present case is also rare by the way in which it was found, by the age of the patient and its being in the pelvic region. Prognosis with these tumors is still very bad regardless of the optimization of a multidisciplinary answer. The research of new biomarkers and target therapy could be a hope for the treatment of these rare and pejorative tumors. J Med Cases. 2016;7(2):58-59 doi: http://dx.doi.org/10.14740/jmc2372w