NK-cell enteropathy: a benign NK-cell lymphoproliferative disease mimicking intestinal lymphoma: clinicopathologic features and follow-up in a unique case series.
Intestinal T-cell and natural killer (NK)-cell lymphomas are clinically aggressive and can be challenging to diagnose in small endoscopic biopsies. We describe 8 patients in whom atypical NK-cell lymphoproliferative lesions mimicked NK- or T-cell lymphoma. The patients (2 men; 6 women; ages 27-68 years) presented with vague gastrointestinal symptoms with lesions involving stomach, duodenum, small intestine, and colon. At endoscopy, the lesions exhibited superficial ulceration, edema, and hemorrhage. Biopsies revealed a mucosal infiltrate of atypical cells with an NK-cell phenotype (CD56(+)/TIA-1(+)/Granzyme B(+)/cCD3(+)), which displaced but did not invade the glandular epithelium. Epstein-Barr virus-encoded RNA in situ hybridization was negative, and T-cell receptor-γ gene rearrangement showed no evidence of a clonal process. Based on an original diagnosis of lymphoma, 3 patients received aggressive chemotherapy followed by autologous bone marrow transplantation in 2. Five patients were followed without treatment. However, no patient developed progressive disease or died of lymphoma (median follow-up, 30 months). Repeat endoscopies in 6 of 8 patients showed persistence or recurrence of superficial gastrointestinal lesions. This unique entity mimics intestinal and NK-/T-cell lymphomas on endoscopic biopsies and can result in erroneous diagnosis, leading to aggressive chemotherapy. We propose the term "NK-cell enteropathy" for this syndrome of as yet unknown etiology.
Department of Pathology & Laboratory Medicine/Calgary Laboratory Services, Calgary, Alberta, Canada.
Adnan
A
Mansoor
Stefania
S
Pittaluga
Paul L
PL
Beck
Wyndham H
WH
Wilson
Judith A
JA
Ferry
Elaine S
ES
Jaffe
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use; D016026:Bone Marrow Transplantation; D003937:Diagnosis, Differential; D016099:Endoscopy, Gastrointestinal; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D007414:Intestinal Neoplasms / Q000175:diagnosis* / Q000276:immunology / Q000628:therapy; D007694:Killer Cells, Natural / Q000276:immunology / Q000473:pathology*; D016399:Lymphoma, T-Cell / Q000175:diagnosis* / Q000276:immunology / Q000628:therapy; D008232:Lymphoproliferative Disorders / Q000175:diagnosis* / Q000276:immunology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis
D000970:Antineoplastic Agents