Report of a case of sinonasal undifferentiated carcinoma arising in a background of extensive nasal gliomatosis

Background. Sinonasal undifferentiated carcinoma (SNUC) is a relatively rare, aggressive malignancy of adulthood. Nasal glial heterotopia is a benign congenital condition in which mature benign brain tissue develops outside the central nervous system. Methods. A 37-year-old man was seen with right nasal obstruction, epistaxis, and headache. Imaging showed a radiologically malignant mass lesion. Biopsy and subsequent resection were performed in the evaluation and treatment of this lesion. Histologic and immunohistochemical assessments of the biopsy and resection specimens on the pathology material classified the lesional tissue. Results. Histology and immunohistochemistry of the biopsy specimen demonstrated an SNUC that was subsequently resected following chemotherapy. In addition to SNUC, the resection specimen revealed extensive, multifocal nasal glial heterotopia (so called "nasal glioma"). Conclusions. This is the first known case in the literature in which these 2 relatively rare entities coincide.