An elusive diagnosis: IPSID presenting as a tuberculosis-like gastrointestinal disorder.

Immunoproliferative Small Intestinal Disease (IPSID) is a rare lymphoproliferative disorder involving the proximal small intestine with no definitive pathogenesis reported. It typically presents with chronic diarrhea, weight loss, and malabsorption, closely mimicking conditions such as abdominal tuberculosis (TB) and celiac disease. Reports from Pakistan are extremely uncommon. We report a 17 years old male with chronic diarrhea and weight loss, initially treated as abdominal TB for six months. Despite partial improvement, his symptoms relapsed with worsening weakness. Lymph node biopsy confirmed IPSID with transformation into B-cell Non-Hodgkin Lymphoma.