CT and MRI features of lacrimal fossa tumors: A retrospective study of 72 cases

Abstract

ct and mri scans of 72 patients were examined, including eight pleomorphic adenomas, five recurrent pleomorphic adenomas, 13 carcinomas, two schwannomas, four dermoid cysts, two dacryops, two cholesterol granulomas, 18 pseudotumors, 18 lymphoid tumors. Features evaluated were shape, borders, calcifications, adjacent bone changes, palpebral lobe involvement, cystic appearance, T1 and T2-weighted intensity.

Adenomas and schwannomas appeared rounded, with sharp margins and rarely associated with bony defects. Recurrent adenomas mainly had a lobulated shape and sharp borders, hyperostosis and bony defects. Carcinomas showed varied shapes, smooth margins, frequent bone erosion and calcifications. Pseudotumors and lymphoid tumors were mainly wedge-shaped, with a frequent palpebral lobe involvement and no bony changes. Margins were blurred in most pseudotumors, and sharp in most lymphoid proliferations. On mri, all diseases showed a low signal on T1 and a high signal on T2, except for pseudotumors (hypointense on both T1 and T2).

Combining shape, cystic appearance and palpebral lobe involvement, in most cases ct can differentiate lesions that should be excised without previous biopsy (epithelial, neurogenic and cystic tumors) from pseudotumors and lymphoid lesions. In epithelial tumors, the suspicion of malignancy should be raised by calcification and an irregular shape. mri proved to be able to distinguish pseudotumors from lymphoid lesions on T2 -weighted sequences and to recognize the contents of cholesterol granulomas.

Key Words:

• Lacrimal gland
• lacrimal fossa
• ct
• mri
• adenoma
• carcinoma
• pseudotumor
• dermoid cyst
• cholesterol granuloma
• dacryops
• lymphoid tumors
• schwannoma