Lacrimal Gland Tumors: What Pace and Pain Tell You Before Biopsy

Lacrimal gland tumors present a diagnostic fork in the road that history alone often resolves. A slow, painless, months-to-years course points toward a benign pleomorphic adenoma.

Meanwhile, rapid growth over weeks accompanied by pain points toward adenoid cystic carcinoma. A classic accompanying clue is numbness in the distribution of the lacrimal branch of the trigeminal nerve.

This is the most feared malignancy of this region, given its distinctive tendency for perineural invasion.

Benign Pleomorphic Adenoma

Pleomorphic adenoma (benign mixed tumor) is the most common lacrimal gland tumor overall.

It typically presents in mid-adulthood as a slowly enlarging, painless mass in the superolateral orbit. As it grows, it often produces gradual, painless downward and inward displacement of the globe.

The tumor has a well-defined capsule on imaging, and this encapsulated character is directly relevant to management. Surgical excision without violating the capsule is what prevents the tumor from seeding and recurring.

This distinction separates its management sharply from most other orbital masses.

Adenoid Cystic Carcinoma

Adenoid cystic carcinoma, by contrast, is the most common malignant epithelial tumor of the lacrimal gland.

It behaves very differently: rapid growth over just weeks to a few months, accompanied by pain. It characteristically also causes numbness in the periocular or forehead region, from perineural invasion along sensory nerve branches.

This numbness is distinctive.

When present with a rapidly growing lacrimal gland mass, it strongly suggests this diagnosis, rather than a benign process.

This tumor’s propensity to spread along perineural spaces is what makes it so difficult to cure. It can track well beyond the visible margins of the mass itself, even with aggressive local treatment.

Other Lacrimal Gland Tumors

• Pleomorphic adenocarcinoma (malignant transformation of a longstanding or recurrent pleomorphic adenoma) — a rapid change in the growth pattern of a previously stable, known pleomorphic adenoma should raise concern for this malignant transformation
• Mucoepidermoid carcinoma and other malignant epithelial tumors — less common than adenoid cystic carcinoma but part of the differential for a malignant lacrimal gland mass
• Lymphoproliferative lesions (lymphoma, reactive lymphoid hyperplasia) — can involve the lacrimal gland and mimic an epithelial tumor clinically, distinguished by histopathology and, often, by the somewhat different clinical course and demographic profile
• Dacryoadenitis (inflammatory rather than neoplastic) — discussed in its own dedicated article on this site, an important entry in the differential given its far greater overall frequency relative to true lacrimal gland tumors

Clinical Evaluation

The history does much of the diagnostic work, before any imaging is even obtained.

It should cover the duration and pace of growth, and the presence or absence of pain and sensory symptoms. This should be elicited carefully in any patient presenting with a superolateral orbital mass.

Palpation distinguishes a mobile, well-defined mass, more typical of pleomorphic adenoma, from a fixed, tender mass more typical of malignancy.

Assessing ocular motility, globe displacement, and facial or periocular sensation also contributes to the pretest likelihood of malignancy.

Imaging

CT demonstrates bony changes well. A longstanding benign pleomorphic adenoma can show smooth, well-defined bony fossa remodeling.

Malignancy more typically shows irregular, destructive bony changes, including erosion into adjacent structures.

MRI provides superior soft-tissue characterization.

It is useful for assessing perineural spread in suspected adenoid cystic carcinoma, since this changes surgical planning and prognosis.

Management

Pleomorphic adenoma is treated with complete surgical excision, taking specific care to remove the tumor with its capsule intact.

Incisional biopsy of a suspected pleomorphic adenoma is generally avoided. Violating the capsule risks tumor seeding and subsequent recurrence.

Recurrence, once it occurs, can be difficult to fully eradicate.

Recurrent disease also carries a long-term, if uncommon, risk of malignant transformation. This is an important point of surgical planning.

A mass with classic imaging for pleomorphic adenoma often goes directly to excisional surgery, rather than biopsy first.

This differs from the general default of biopsy-before-definitive-treatment used for most other suspected tumors.

Adenoid cystic carcinoma requires a fundamentally more aggressive approach.

This typically means wide surgical excision, sometimes including orbital exenteration for extensive disease, combined with adjuvant radiation therapy.

This reflects the tumor’s propensity for perineural spread and local recurrence. Despite aggressive multimodal treatment, long-term prognosis remains guarded for this tumor.

Management is generally coordinated among ophthalmic oncology, head and neck surgery, and radiation oncology.

This reflects the complexity of the disease and its treatment.

References

• Font RL, Gamel JW. Epithelial tumors of the lacrimal gland: an analysis of 265 cases. In: Ocular Pathology.
• Ni C, Cheng SC, Dryja TP, Cheng TY. Lacrimal gland tumors: a clinicopathological study of 265 cases. International Ophthalmology Clinics.
• American Academy of Ophthalmology. Basic and Clinical Science Course, Section 7: Orbit, Eyelids, and Lacrimal System.