Primary Extranodal Natural Killer/T-cell Lymphoma in a Child in the Colon: A Case Report

Rationale: Primary extranodal natural killer (NK)/T-cell lymphoma (ENKTL) rarely occurs in childhood and adolescence. To the best of our knowledge, ENKTL of childhood in the gastrointestinal (GI) tract has not been reported yet.

Patient Concerns: A 12-year-old Chinese boy complained of abdominal pain and persistent fever for 1 month.

Diagnosis: Grossly an ulcerated tumor with perforation was located at the proximal ascending colon, 5 cm × 4 cm × 1.5 cm in diameter. The tumor was poorly circumscribed, tan-white and solid. Histological evaluation revealed medium-sized atypical lymphoid cells with large areas of necrosis distributed throughout all layers of the colon. Small blood vessels with destroyed walls were surrounded by lymphoid cells. Immunohistochemistry (IHC) highlighted tumor cells as strongly positive for CD3, CD56, CD5, CD2, CD8, CD4, CD43, T-cell restricted intracellular antigen 1 (TIA-1) and granzyme B. The proliferation index, measured by Ki-67 expression was high with 60%. The In situ hybridization (ISH) for EBER was positive. TCR was negative. Therefore, the final diagnosis was ENKTL of childhood in the colon.

Interventions: The patient underwent right hemicolectomy and ileocolostomy.

Outcomes: We recommended further evaluation and treatment, but the patient and patient family rejected further treatment of his condition. The patient died within 1 month after being discharged from hospital as a result of his disease.

Lessons: ENKTL of childhood in the GI tract is extremely rare. Due to the non-specific clinical symptoms, it is easy it is easy not to think of this differential diagnosis at early stage. If patients have GI symptoms, ENKTL cannot easily be ignored. It is necessary to diagnose ENKTL of childhood in the GI tract by morphology and immunohistochemistry, and to differentiate from the GI T-cell lymphomas. We hope this case may serve as a reference improving clinical diagnosis and treatment.