Incidental ileal schwannoma mimicking acute appendicitis: an intraoperative diagnostic challenge

Schwannomas are benign peripheral nerve tumors, with gastrointestinal involvement being rare and ileal origin exceptionally uncommon. Their nonspecific symptoms often mimic acute abdominal conditions, complicating preoperative diagnosis. A 40-year-old female presented with acute right iliac fossa pain, nausea, vomiting, and fever, initially suggestive of acute appendicitis. Ultrasonography showed a blind-ending tubular structure. During emergency appendicectomy, the appendix appeared normal, but an exophytic ileal mass was identified. Segmental ileal resection with primary anastomosis was performed. Histopathology revealed spindle cells with Antoni A and B areas, and immunohistochemistry was strongly positive for S-100, confirming schwannoma. Postoperative computed tomography of abdomen and pelvis showed no additional lesions. The patient also had multiple cutaneous lesions and was referred to dermatology for further evaluation. Ileal schwannoma is a rare cause of acute abdomen and may mimic appendicitis. Histopathology and immunohistochemistry are essential for diagnosis, while complete surgical excision is curative. Postoperative imaging ensures comprehensive assessment.