Lymph node involvement by enteropathy-like indolent NK-cell proliferation

Natural killer (NK)-cell enteropathy (NKCE) and lymphomatoid gastropathy (LG) are closely related lymphoproliferative disorders (LPDs) composed of mature and Epstein-Barr virus (EBV)-negative NK-cells. Although these uncommon and indolent lymphoid proliferations mostly arise within the gastrointestinal (GI) tract as their designations implies, a few cases have been reported outside the GI tract. We hereby describe a unique case of lymph node infiltration by such EBV-negative NK-cell proliferation fortuitously found during routine examination of a gallbladder resected for biliary lithiasis. The histologic, phenotypic, and molecular features of this NK-cell proliferation, which were very similar if not identical to those previously reported in NKCE or LG, suggest that similar indolent EBV-negative NK-cell LPDs may also occasionally involve lymph nodes.

Automated summary

NKCE and LG are closely related lymphoproliferative disorders composed of mature and EBV-negative NK cells, mainly arising within the gastrointestinal tract but occasionally involving other sites. This case report describes a unique lymph node infiltration by such EBV-negative NK cell proliferation, exhibiting similar features to NKCE or LG, suggesting occasional lymph node involvement by similar indolent EBV-negative NK cell LPDs.