Common Presentation of an Uncommon Small Intestinal Lymphoma: A Rare Case Entity.

Primary gastrointestinal NHL accounts for 30-40% of all extranodal NHL. Primary gastrointestinal lymphomas constitute 5% of total gut neoplasms. Bowel perforation is a severe life-threatening complication and sometimes initial presentation of gastrointestinal lymphoma. A 60-year-old man presented with complaints of abdominal pain, distension, nausea and vomiting. There was clinical suspicion of acute intestinal perforation, which was confirmed by radiology. The patient underwent emergency laparotomy. The resected bowel on histopathological examination and immunohistochemistry was diagnosed as the high-grade transformation of follicular lymphoma (FL). The patient received 6 cycles of chemotherapy and is doing well at 3 years of follow-up. Herein, we report this rare malignancy of the small intestine. FL mostly presents as a nodal disease but also involves the extranodal sites. The most common site of primary gastrointestinal-follicular lymphoma (GI-FL) is the small intestine. The cellular and molecular characteristic of GI-FL is different from that of the nodal FL. Extranodal FL is usually localized, but the prognosis of transformed FL is low, and these are managed by surgery followed by chemotherapy. High clinical suspicion and extensive sampling of perforated bowel are essential to diagnose the high-grade transformation of FL.