A case of excisionally remitted indolent NK-cell enteropathy in the oral cavity and a mini-review.

Benign natural killer cell enteropathy (NKCE) was first identified in the gastrointestinal (GI) tract. Notably, instances of NKCE have previously been observed at various sites other than the GI tract, including the gallbladder, lymph nodes, esophagus, and female genital tract. Typical NKCE manifests as an NK-cell immunohistological phenotype, with or without TCR rearrangement, and is characterized by the absence of Epstein-Barr virus (EBV) infection and protracted clinical progression. The misdiagnosis of NKT-cell lymphoma has resulted in some patients receiving chemotherapy, while in other instances, the patients' conditions resolved without treatment and showed no evidence of disease recurrence or progression during follow-up examinations. In this paper, we describe a unique case of EBV-negative NKCE occurring in the oral cavity, the first time such a case has been documented. The tumor completely resolved after an excisional biopsy, and subsequent follow-up did not reveal any signs of disease recurrence.