A previously healthy 60-year-old man developed intermittent fevers, night sweats, and fatigue. Initial physical exam and routine blood work were both unremarkable. About 2 months later, he developed acute onset abdominal pain, nausea, and vomiting and presented to an emergency room where he was diagnosed with infectious colitis and treated with antibiotics. He then developed a rash with swollen joints. Skin biopsy of his rash appeared reactive. He was empirically treated with prednisone with improvement of symptoms. Soon after, the abdominal pain returned, and a computed tomography scan showed intraperitoneal free air. He underwent emergent surgery for a perforated small bowel and was noted to have a large mass in the small bowel, which was resected with re-anastomosis. Review of the resected mass showed (Figure 1A) complete effacement of the bowel wall with atypical intermediate to large lymphocytes with open chromatin and prominent nucleoli. Atypical cells infiltrated the surrounding fat. Immunohistochemistry demonstrated lymphocytes that were strongly positive for CD3, CD30 (positive in 80% of tumor cells) BCL-2, and MUM-1. CD4 was focally positive. CD8, CD10, EMA, CD5, CD20, CD56, EBER, ALK-1, CD25, CD15, and cyclin D1 were negative. The Ki-67 was 80%. Molecular studies showed a T-cell receptor (TCR) ? and ß chain rearrangement. Changes consistent with enteropathy were not seen. The diagnosis was PTCL-NOS with 80% CD30 expression. (Figure B) FDG-PET/CT fusion image showing multiple foci of lymphoma throughout the bowel.