Abstract
BACKGROUND: Gastrointestinal lymphoma typically arises in the stomach, small bowel, or colorectum and is usually a B-cell lymphoma. However, primary T-cell lymphomas originating in the stomach are particularly rare. Gastric peripheral T-cell lymphoma-not otherwise specified (PTCL-NOS) is an extremely rare subtype. CASE SUMMARY: We report a 63-year-old male presenting with epigastric pain. Esophagogastroduodenoscopy revealed a large ulcerative lesion in the gastric cardia. Biopsy and immunohistochemical profiling confirmed PTCL-NOS. Imaging indicated stage II disease involving the stomach and intra-abdominal lymph nodes. The patient is planned to undergo cyclophosphamide, doxorubicin, vincristine, and prednisone or cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide chemotherapy. CONCLUSION: This case highlights the necessity of considering PTCL-NOS in differential diagnoses of gastric lesions. Comprehensive histopathological and immunohistochemical analysis is crucial for accurate diagnosis and guiding treatment.