A Diagnostic Enigma: A Rare Case of Cholesterol Granuloma of Mastoid Masquerading as Acute Mastoiditis in a Young Female.

Cholesterol granuloma is a rare, benign lesion of the mastoid air cells, often associated with glue ear and typically presenting unilaterally. Histopathologically, it comprises of granulation tissue with cholesterol crystals, multinucleated giant cells, and hemosiderin deposits from erythrocyte breakdown. While commonly found in the petrous apex, tympanomastoid cholesterol granulomas are rare, with very few cases reported in literature. It can mimic other otological conditions, leading to diagnostic challenges. We report a rare case of cholesterol granuloma presenting as acute mastoiditis in a 24-year-old female with type 1 diabetes. She presented with postauricular swelling, pain, fever, and hearing loss. Imaging revealed a cystic lesion with bony erosion in the mastoid antrum. Surgical exploration uncovered a lobulated cyst containing thick fluid, which was managed via marsupialization and reconstruction. Histopathology confirmed the diagnosis of cholesterol granuloma. This case underscores the need for clinical suspicion of rare pathologies in chronic otitis media cases and highlights the importance of timely intervention to prevent complications.