A difficult‐to‐diagnose case of extranodal NK/T‐cell lymphoma, nasal type, primary to maxillary gingival ulcers that developed after living‐donor liver transplantation

Extranodal nasal‐type NK/T‐cell lymphoma (ENKTL) is a hematopoietic malignancy that is rare in the oral cavity. We report a case of a 62‐year‐old woman who developed ENKTL after undergoing living‐donor liver transplantation at the age of 53 years. She had a history of hepatitis C‐related liver cirrhosis. After being diagnosed with necrotizing ulcerative gingivitis, she received antibiotic therapy; however, it was ineffective. Clinical findings suggested a neoplastic disease and necessitated a gingival biopsy. A definitive diagnosis of ENKTL was made based on the immunohistochemical analysis. She achieved a complete clinical response after two courses of SMILE chemotherapy.