Lacrimal Lesions

A pattern-based approach to lacrimal-gland masses uses laterality, lobe distribution, pain, bone response, enhancement, diffusion, and MRI signal to narrow the differential.Unilateral orbital-lobe mass → consider epithelial neoplasm • Bilateral diffuse enlargement of both lobes → consider lymphoid or inflammatory disease

Reference Images

Overview of lacrimal gland diseases and tumors — Lacrimal gland disease and tumor overview

Normal Anatomy & Imaging

Almond-shaped gland in the superolateral orbit, adjacent to superior and lateral rectus muscles.
Orbital lobe: larger, posterior and superior to the levator aponeurosis.
Palpebral lobe: smaller, anterior and inferior to the levator aponeurosis.
Normal size approximately 20 × 12 × 5 mm; symmetry is expected.
CT: approximately isodense to muscle; best for calcification and bone response.
MRI: best for soft-tissue, periglandular, and perineural extension.

Diagnostic Framework

Pattern	More likely category	Key clues
Unilateral orbital-lobe mass	Epithelial neoplasm	Inferomedial globe displacement; remodeling versus destruction
Bilateral diffuse enlargement of both lobes	Lymphoid or inflammatory	Molds to globe; usually no destructive bone change
Painful, rapidly enlarging unilateral gland	Infection or malignant epithelial tumor	Inflammation/abscess versus destruction/perineural spread
Homogeneous restricted mass	Lymphoma	Often painless; both lobes; no destructive bone lesion
T2-hypointense diffuse enlargement	Fibroinflammatory / IgG4-related process	Variable enhancement; often steroid responsive

Approximate distribution: 50% inflammatory, 25% lymphoid/lymphomatous, and 25% salivary-gland–type tumors. Atypical lesions require tissue diagnosis.

Epithelial Tumors

Lesion	Clinical pattern	Imaging	Bone / perineural behavior
Pleomorphic adenoma	Age 20–40; slow, painless unilateral proptosis	Well-circumscribed orbital-lobe mass; moderate enhancement	Smooth scalloping/remodeling
Adenoid cystic carcinoma	Often painful; sometimes paresthesia	Solid enhancing unilateral orbital-lobe mass	Destruction and marked perineural-spread propensity
Mucoepidermoid carcinoma	Painful, relatively rapid proptosis	Can resemble adenoid cystic carcinoma	Scalloping or destruction; local invasion

Red flags for malignancy: pain, rapid progression, osseous destruction, and perineural extension. For suspected adenoid cystic carcinoma, inspect V1/V2 pathways, superior orbital fissure, orbital apex, cavernous sinus, foramen rotundum, and pterygopalatine fossa.

Lymphoid & Infiltrative

Reactive hyperplasia

Usually bilateral, diffuse, and involves both lobes.
Conforms to the globe; often no bone destruction.

Lymphoma

Typically painless and homogeneous.
Often bilateral; both lobes; molds to adjacent structures.
Restricted diffusion supports hypercellularity.
Destructive bone change is usually absent.

Other

Granulocytic sarcoma in children/young adults with AML.
Metastases may arise from breast, prostate, kidney, thyroid, or melanoma.

Inflammatory Disease

Entity	Pattern	Imaging clues	Clinical clue
Infectious dacryoadenitis	Usually unilateral; both lobes	Avid enhancement, fat inflammation, possible rim-enhancing abscess	Acute painful proptosis
Sarcoidosis	Typically bilateral; both lobes	Diffuse hyperenhancement; no bone involvement	Thoracic adenopathy; uveitis
Idiopathic orbital inflammation / IgG4-related	Often unilateral; both lobes	Relatively low T2 signal; variable enhancement; no destruction	Painful; relapsing; steroid responsive
Sjögren syndrome	Bilateral diffuse	Early enlargement; later fatty replacement and atrophy	Dry eyes and mouth

Reporting Checklist

Unilateral or bilateral?
Orbital lobe, palpebral lobe, or both?
Focal or diffuse; does it mold to the globe?
Pain, rapid onset, or fat stranding?
Bone remodeling or destructive erosion?
Restricted diffusion or low T2 signal?
Abscess or perineural extension?
Extension to SOF, apex, cavernous sinus, PPF, muscles, fat, or regional bone?