Incidental giant subserosal lipoma of the transverse colon with fat necrosis and abscess formation discovered during emergency laparotomy for blunt abdominal trauma: a case report.

Giant subserosal colonic lipomas are rare, benign tumors that are typically asymptomatic. However, they can mimic malignancy or become complicated by inflammation and necrosis. We present a 59-year-old male who underwent emergency laparotomy for a traumatic splenic rupture following blunt abdominal trauma. During surgery, a 12 × 10 cm incidental mass in the transverse colon was discovered, mimicking a malignant tumor. Due to gross purulent intra-abdominal contamination from an intratumoral abscess and patient instability, a segmental colonic resection with an end colostomy was performed alongside the splenectomy. Histopathology confirmed a giant subserosal lipoma complicated by fat necrosis and abscess formation. This case highlights a highly unusual presentation of an inflamed colonic lipoma discovered incidentally during trauma surgery. It underscores the diagnostic difficulty of benign tumors in acute settings and supports definitive surgical resection when malignancy cannot be excluded.