Metachronous nasopharyngeal carcinoma masquerading as a base of skull metastasis in a case of primary extraskeletal vulvar Ewing’s sarcoma

ABSTRACT

Ewing’s sarcoma (ES) and primitive neuroectodermal tumor (PNET) resemble each other and commonly affect the skeletal system. Extraskeletal ES/PNET is a rare neoplasm. Here, we report a case of primary vulvar ES in an 18-year-old adolescent girl confirmed by histopathology and immunohistochemistry, who underwent surgery followed by adjuvant chemotherapy. Following 1 year of chemotherapy, she presented with multiple cranial nerve palsies (VI, IX, X, and XII). Contrast tomography of the base of the skull and nasopharynx showed a heterogeneous mass lesion involving the base of skull, sphenoid sinus, and left nasopharynx. Biopsy from the left nasopharyngeal mass revealed it to be well-differentiated squamous cell carcinoma, which was initially thought of metastasis to the base of the skull. In spite of its aggressive nature, a patient of primary sarcoma presenting with a second lesion should be adequately investigated before considering it as a metastatic lesion.