An 18-year-old man presented with sudden vision loss in his left eye. Magnetic resonance imaging revealed a tumor that had invaded the left optic nerve, originating from the left posterior ethmoid sinus. Immunohistochemical analyses identified positive staining for NUT protein in the nuclei of tumor cells. We diagnosed locally advanced NUT carcinoma (NC) and initiated concurrent chemoradiotherapy (CCRT), consisting of chemotherapy with vincristine, doxorubicin, and cyclophosphamide, alternating with ifosphamide and etoposide, plus radiation therapy. The patient achieved a complete response. CCRT can be a useful treatment option for adolescent and young-adult patients with locally advanced unresectable NC.

BackgroundNUT carcinoma (NC) is a rare and extremely aggressive carcinoma that occurs in young individuals. Although NC has a dismal prognosis, recommended therapies have not been established.Case presentationAn 18-year-old man presented with sudden vision loss in his left eye. Magnetic resonance imaging revealed a rapidly growing tumor, which had directly invaded the left optic nerve and epidural space, originating from the left posterior ethmoid sinus. A pathological examination of the tumor revealed a dense proliferation of polygonal-to-round tumor cells with enlarged round nuclei and conspicuous nucleoli, and positive staining for NUT protein in the nuclei of tumor cells. The patient was diagnosed with locally advanced NC. We initiated concurrent chemoradiotherapy (CCRT), consisting of chemotherapy with vincristine, doxorubicin, and cyclophosphamide (VDC), alternating with ifosphamide and etoposide (IE) according to a regimen for Ewing sarcoma, plus radiation therapy (70 Gy/35 Fr). The patient completed CCRT and achieved a complete response.ConclusionsCCRT, comprising a VDC–IE regimen, can be a useful treatment option for adolescent and young adult patients with NC, even when the cancer is at a locally advanced unresectable stage.