NUT carcinoma of the nasal cavity that responded to a chemotherapy regimen for Ewing's sarcoma family of tumors: a case report.

BACKGROUND: Nuclear protein in testis (NUT) carcinoma (NC) is a rare epithelial malignancy characterized by rearrangement of the NUT gene on chromosome 15. If NC is not suspected, it is often diagnosed as other malignancies. We present the case of NC of the nasal cavity that responded to a chemotherapy regimen for Ewing's sarcoma family of tumors (ESFT).

CASE PRESENTATION: A 49-year-old male presented with epistaxis and pain in the left eye. The patient had a tumor in the left nasal cavity at initial visit and it was biopsied. Firstly, the man was diagnosed with ESFT based on a histopathological examination. The tumor markedly responded to standard cytotoxic chemotherapy for ESFT with distant metastasis. After the start of therapy, a chromosomal analysis revealed an atypical translocation in ESFT and additional immunostaining was positive for anti-NUT antibody. Ultimately, the patient was definitively diagnosed with NC. He received multidisciplinary therapy and symptoms were temporarily relieved. However, he died 9 months after the diagnosis of NC.

CONCLUSIONS: When a pathologically undifferentiated tumor is evident along the midline of the body, NC must be included in the differential diagnosis, and immunohistochemical staining or genetic testing/chromosomal analysis needs to be performed.