[Type II enteropathy-associated T-cell lymphoma: a clinicopathologic study]

Area of Science:

• Gastrointestinal Pathology
• Hematopathology
• Oncology

Background:

• Enteropathy-associated T-cell lymphoma (EATL) is a distinct subtype of non-Hodgkin lymphoma.
• Type II EATL presents unique clinicopathologic features compared to Type I EATL.

Purpose of the Study:

• To elucidate the clinicopathologic characteristics of type II EATL.
• To analyze immunohistochemical findings, differential diagnoses, and prognosis of type II EATL.

Main Methods:

• Retrospective review of 14 cases of type II EATL.
• Analysis of clinical data, histology, immunohistochemistry, and follow-up information.
• Literature review for comparative analysis.

Main Results:

• Median age of 49 years, predominantly in males (12/14).
• Commonly involves jejunum; symptoms include abdominal mass, pain, diarrhea, and constitutional symptoms.
• Histology shows full-thickness infiltration, villous atrophy, cryptal hyperplasia, and intraepithelial lymphocytosis. Tumor cells express CD3, CD43, CD8, and variably CD56.
• High Ki-67 proliferation index; EBER in situ hybridization negative.
• Poor prognosis with 7 of 9 patients dying within 14 months.

Conclusions:

• Type II EATL is a rare intestinal lymphoma with distinct features.
• Associated enteropathy is not consistently demonstrated, differing from Nordic EATL cases.
• Accurate diagnosis relies on integrating clinical, pathological, and ancillary test findings.