A 38-year-old woman has a painless, slowly growing, firm mass in the superotemporal part of the left orbit displacing the globe inferomedially. CT shows a well-defined oval mass with smooth remodelling of the adjacent lacrimal fossa bone. Incisional biopsy of this lesion is avoided primarily because it:

• A Causes haemorrhage from the lacrimal artery
• B Induces conversion into adenoid cystic carcinoma within months
• C Damages the frontal branch of the facial nerve
• D Risks seeding tumour cells and subsequent recurrence or malignant change ✓

Explanation

The picture is pleomorphic adenoma of the lacrimal gland, the commonest benign epithelial lacrimal gland tumour of young adults. Capsular breach by incisional biopsy implants tumour cells, leading to multifocal recurrence and an increased risk of malignant transformation over time. Definitive management is complete intact excision via lateral orbitotomy. It does not transform abruptly into adenoid cystic carcinoma, which arises de novo.

Reference: Kanski's Clinical Ophthalmology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.