Right Iliac Fossa Mass: A Rare Case of Parietal Surface of Abdominal Wall Tumor with Multi-Modal Diagnostic Discrepancy Including Radiological and Clinical Misinterpretation with Histopathological Diagnostic Dilemma Followed by IHC Discrepenc

Background: Right iliac fossa (RIF) masses present a complex diagnostic challenge due to diverse etiologist involving gastrointestinal, gynecological, and soft tissue structures. We report a rare case of a 42-year-old female presenting with a right iliac fossa mass, where clinical evaluation and radiological imaging initially suggested an intra-abdominal pathology. However, intraoperative findings revealed the lesion to be arising from the anterior abdominal wall. Histopathological examination showed a hypocellular spindle cell tumor consistent with leiomyoma, with gastrointestinal stromal tumor (GIST) as a differential diagnosis. Immunohistochemistry was recommended for confirmation. This case highlights a rare diagnostic discrepancy across clinical, radiological, and surgical evaluation, emphasizing the importance of histopathology and ancillary techniques in distinguishing soft tissue tumors.

Keywords: Right Iliac Fossa Mass, Abdominal Wall Tumor, Parietal Surface Lesion, Diagnostic Discrepancy, Radiological Misinterpretation, Clinical Misdiagnosis, Histopathological Dilemma, Immunohistochemistry (IHC).