Lacrimal Gland Tumours

Lacrimal gland masses are about 50 percent inflammatory or lymphoid, and about 50 percent epithelial tumours. Of the epithelial tumours, about 50 percent are benign and 50 percent malignant.

• Benign: pleomorphic adenoma (benign mixed tumour), commonest epithelial tumour, mean age 40 years, slow growth over more than 12 months, painless.
• Malignant: adenoid cystic carcinoma (about 25 to 30 percent of epithelial tumours, perineural spread, pain, rapid growth), carcinoma ex pleomorphic adenoma, adenocarcinoma, mucoepidermoid carcinoma, and primary squamous cell carcinoma.
• Lymphoid: marginal zone (MALT) lymphoma, other lymphomas, and reactive lymphoid hyperplasia.

• Pleomorphic adenoma: painless, firm, smooth mass in the superolateral orbit with downward and inward displacement of the globe, mild proptosis, and a long history (over 12 months).
• Adenoid cystic carcinoma: shorter history (under 12 months), pain or paraesthesia from perineural invasion, rapid progression, diplopia, ptosis, motility restriction, bone destruction.
• Lymphoma: painless, bilateral in some, moulded mass, with systemic B symptoms in some.
• Dry eye is unusual for tumours that do not destroy the whole gland.

• CT orbits (bone windows): pleomorphic adenoma shows a well circumscribed, round or oval mass in the lacrimal fossa with smooth bone remodelling (fossa expansion) and rare calcification; malignant lesions are irregular, with bone erosion and calcification.
• MRI orbits with contrast for soft tissue, cavernous sinus and perineural spread along cranial nerves V1 and V2.
• For a suspected pleomorphic adenoma, do not biopsy (risk of tumour seeding and recurrence, with malignant transformation); proceed to en bloc excision with the capsule intact.
• For irregular or suspected malignant masses, lymphoma or inflammation: incisional biopsy; fine needle aspiration is not advised.
• Systemic staging for malignancy: CT chest and abdomen, bone scan, MRI brain.

• Pleomorphic adenoma: complete excision of the whole gland with its intact pseudocapsule and surrounding tissue through a lateral orbitotomy, ideally with the periosteum. Incomplete excision leads to recurrence (up to 30 percent) and malignant change (10 to 20 percent over 20 years).
• Adenoid cystic carcinoma and other malignant tumours: radical resection (orbital exenteration with removal of involved bone and periorbita) with adjuvant radiotherapy (60 to 66 Gy) and in some cases proton or carbon ion therapy. Alternative globe sparing approach: neoadjuvant intra arterial cytoreductive chemotherapy (cisplatin 100 to 150 mg/m2 and doxorubicin 25 mg/m2), followed by exenteration and radiation.
• Lymphoma: rituximab based therapy or radiotherapy (24 to 30 Gy for MALT, 4 Gy low dose for indolent disease), with systemic evaluation.
• Reactive and inflammatory lesions: oral prednisolone 1 mg/kg daily (maximum 60 to 80 mg) tapered over 6 to 8 weeks, with steroid sparing agents (methotrexate 15 to 25 mg weekly, rituximab 1 g on days 1 and 15) for relapsing or IgG4-related disease.
• Follow up with imaging at 3 to 6 months, then annually, as late recurrence and metastases (lung, bone, brain) occur.