Extranodal NK/T-cell lymphoma, nasal type, presenting as a necrotic palatal ulcer

Abstract

Extranodal natural killer/T-cell lymphoma (ENKTL), nasal type, is an aggressive Epstein–Barr virus (EBV)-associated lymphoma that predominantly involves the nasal cavity and upper aerodigestive tract. Primary oral manifestations are rare and may clinically mimic benign inflammatory or infectious conditions, resulting in delayed diagnosis. This report presents a rare case of ENKTL initially manifesting as a rapidly progressive necrotizing palatal ulcer. A 44-year-old man presented with a three-week history of a necrotic ulcer on the posterior hard palate. Imaging revealed extensive midfacial destruction, including palatal perforation, nasal septal erosion, turbinate destruction, ethmoidal involvement, and medial orbital wall extension. Histopathologic examination demonstrated atypical large lymphoid cells with extensive necrosis and infiltration into adipose and muscle tissue. Immunohistochemical staining demonstrated diffuse expression of LCA and CD3, focal expression of CD30, absence of CD20, ALK, and CD56 expression, and a high proliferative activity, as evidenced by a Ki-67 index of approximately 90%. Based on the histomorphologic and immunophenotypic features, extranodal NK/T-cell lymphoma was suspected. Chromogenic in situ hybridization (CISH) for Epstein–Barr virus-encoded RNA (EBER) demonstrated strong nuclear positivity in atypical lymphoid cells, confirming the diagnosis of ENKTL, nasal type. The patient achieved complete remission after chemotherapy; however, eight months later, the patient developed a systemic relapse that was diagnosed as peripheral T-cell lymphoma. This case highlights the diagnostic complexity of ENKTL presenting as a destructive palatal lesion. Comprehensive histopathologic evaluation, detailed immunophenotyping, and EBV confirmation by EBER are essential for accurate diagnosis and timely oncologic management. ENKTL should be considered in the differential diagnosis of rapidly progressive oral necrotic lesions unresponsive to conventional therapy.