Inflammatory pseudotumour of the spleen complicated by a cholesterol granuloma: a diagnostic dilemma.

Inflammatory pseudotumours (IPTs) and cholesterol granulomas (CG) are rare benign lesions that often mimic malignancy on imaging, creating significant diagnostic uncertainty. We report the case of a 67-year-old man with a long-standing calcified splenic cyst who developed new abdominal symptoms secondary to extrinsic compression of the stomach by the lesion and subsequently underwent a laparoscopic splenectomy. Histopathology confirmed an IPT with xanthogranulomatous inflammation. Six months later, a surveillance positron emission tomography scan revealed a solitary fluorodeoxyglucose-positron (FDG) avid left upper quadrant lesion concerning for malignancy in the context of newly diagnosed cutaneous squamous cell carcinoma. Laparoscopic resection and subsequent histopathology demonstrated a CG at the splenectomy site. This case highlights the diagnostic challenges posed by IPT and CG, emphasizes their potential to mimic malignant disease radiologically, and reinforces the importance of histopathological confirmation to guide appropriate management.