NONSEMINOMATOUS GERM CELL TUMOR METASTATIC TO THE MAXILLA

Abstract

Background Extragonodal germ cell tumors (GCTs) primarily affect the sacrococcygeal region. Head and neck GCT is rare and accounts for 3% of pediatric neoplasms. Only isolated cases of metastatic GCT have been reported. Objective To report a unique case of a metastatic nonseminomatous GCT of mixed phenotype with yolk sac tumor, embryonal carcinoma, and immature teratoma components. Clinical Findings A 13-year-old male patient presented with a rapidly enlarging, painless right maxillary tuberosity mass, present for 4 months. The tumor was on the buccal gingiva extending to the hard and soft palate posteriorly. Ipsilateral submandibular lymphadenopathy was evident. No pathology was noted on the panelipse and periapical radiographs. The clinical impression was that of a lymphoma or Kaposi sarcoma. Pathologic Findings The histology showed an extensively infiltrative high-grade malignancy composed of small, round, blue discohesive tumor cells demonstrating a solid growth pattern, with areas of adenocarcinoma and squamous differentiation with keratinization. Surface dysplasia was not present. Brisk mitotic activity was noted. Immunohistochemistry revealed positivity with for AE1/AE3, SALL4, Glyplican 3, and OCT3/4, confirming the diagnosis of a metastatic nonseminomatous GCT of mixed phenotype. Summary Benign teratomas are the most common childhood extragonodal tumors, followed by yolk sac tumors, which frequently arise in the ovaries and testis. Yolk sac tumors that frequently arise in the ovaries and testis have been reported but continue to be a rare extragonodal tumor and are difficult to diagnose. This report reviews germ cell tumors in the spectrum of metastatic disease to the oral cavity.