Peripheral primitive neuroectodermal tumor of the mandible with cytogenetic & molecular biology aberrations

Abstract

5594 Objective and Importance: Peripheral primitive neuroectodermal tumors (pPNET) are rare types of malignant neoplasms, most commonly found in the limbs of children and young adults. The authors report an extremely rare case of pPNET of the mandible with rapid progression, with both cytogenic and chromosomal studies representing the first case in the literature sharing clincopathological, molecular biology aberration and surgical reconstruction findings. Clinical Presentation: An 18-year old African American girl presented with rapidly growing painless mass and induration at the chin area of the mandible at the end of her first pregnancy, without any associated symptoms. Intervention: The patient was treated with 2 cycles of outpatient (Adriamycin, Vincristine and Cytoxan) and inpatient treatment (Ifosffamide, Mesna, and VP-16), subsequently patient had partial mandibulectomy, resection floor of the mouth, bilateral selective neck dissection, free fibula flap and osteointegrated implant for reconstruction. Conclusion: The pathological finding of the surgical specimen was pPNET. Fluorescence in situ hybridization (FISH) did not show deletion (5)(p11), or translocation (11; 22)(q24; q12) in the analyzed cells. The detected t (11; 22) is diagnostically important cytogenetic rearrangement typical of ES/pPNET in 90% of tumors. This case represents a rare variant of pPNET. To the best of our knowledge, this is the third reported case of pPNET of the mandible and the first one with cytogenetic and molecular biology study in the literature. Pathological features, chromosomal analysis, cytogenetic and molecular aberrations are crucial for accurate diagnosis. Multidisplinary approach is necessary in the management of this rare tumor. No significant financial relationships to disclose.