Orbital Tumours & Lacrimal Gland Lesions
Ophthalmology · Orbit · lean revision notes
Orbital Tumours & Lacrimal Gland Lesions
The orbit is a cone packed with optic nerve, extraocular muscles, fat, vessels and the lacrimal gland — any of these may give rise to a mass. For NEET PG, the highest-yield discriminators are age of the patient, rate of growth, and the direction of proptosis, because each lesion has a near-signature combination of these features.
Orientation: how to think about an orbital mass
An orbital mass declares itself through proptosis (forward displacement of the globe), and the direction and speed of that proptosis localise and characterise it.
- Axial (straight forward) proptosis → lesion within the muscle cone (intraconal) — classically the optic nerve glioma, meningioma, or cavernous haemangioma.
- Eccentric (non-axial) proptosis → lesion outside the cone (extraconal); the globe is pushed away from the mass (e.g. a superotemporal lacrimal gland tumour pushes the eye down and in).
- Rapid onset → inflammatory, infective (orbital cellulitis), or malignant (rhabdomyosarcoma, metastasis).
- Slow, painless → benign (cavernous haemangioma, pleomorphic adenoma).
- Pulsatile proptosis → carotico-cavernous fistula, or a bony defect (neurofibromatosis type 1 with absent greater wing of sphenoid).
- Intermittent proptosis worsening on stooping/Valsalva → orbital varix or lymphangioma.
High-yield: Cavernous haemangioma is the commonest benign orbital tumour in adults. Rhabdomyosarcoma is the commonest primary orbital malignancy in children. Pleomorphic adenoma is the commonest epithelial tumour of the lacrimal gland. Capillary haemangioma is the commonest orbital tumour of infancy.
Classification of orbital tumours
| Category | Benign | Malignant |
|---|---|---|
| Vascular | Capillary haemangioma, Cavernous haemangioma, Lymphangioma, Orbital varix | Angiosarcoma (rare) |
| Neural | Optic nerve glioma, Meningioma, Neurofibroma, Schwannoma | Malignant optic glioma (rare) |
| Cystic/developmental | Dermoid cyst, Epidermoid, Mucocele | — |
| Mesenchymal | — | Rhabdomyosarcoma |
| Lacrimal gland | Pleomorphic adenoma (benign mixed tumour) | Adenoid cystic carcinoma, Pleomorphic adenocarcinoma, Mucoepidermoid Ca |
| Lymphoid | Reactive lymphoid hyperplasia | Orbital lymphoma (usually MALT/NHL) |
| Secondary/metastatic | — | Neuroblastoma (children), Breast/Lung/Prostate (adults), Retinoblastoma extension |
High-yield: In children, the commonest orbital metastasis is neuroblastoma (presents with proptosis + ecchymosis — "raccoon eyes"). In adults, the commonest source of orbital metastasis is breast carcinoma (notably scirrhous breast Ca may cause enophthalmos due to fibrosis).
Vascular tumours
Capillary haemangioma (infantile haemangioma)
- Commonest orbital tumour of infancy/childhood. Appears in the first few weeks of life, grows for 6–12 months, then involutes spontaneously by 5–7 years.
- Superficial lesions look like a "strawberry naevus"; deeper lesions cause bluish lid swelling that enlarges on crying (raised venous pressure).
- Major risk = amblyopia from induced astigmatism, anisometropia, or occlusion of the visual axis (deprivation amblyopia).
- Histology: proliferating endothelial cells forming capillary channels; GLUT-1 positive (distinguishes it from other vascular lesions).
- Treatment: because most involute, observe small lesions. For sight-threatening lesions the drug of choice is oral propranolol (has replaced systemic steroids and intralesional steroids).
Cavernous haemangioma
- Commonest benign orbital tumour in adults (3rd–5th decade, slight female preponderance).
- Intraconal location → slowly progressive, painless axial proptosis. May cause acquired hypermetropia and choroidal folds by indenting the posterior globe.
- Encapsulated mass of large dilated vascular channels with smooth muscle.
- Imaging: well-defined intraconal mass; on contrast CT/MRI shows progressive ("filling-in") enhancement from a focal nodule.
- Treatment: surgical excision (lateral orbitotomy) only if symptomatic; it shells out cleanly because it is encapsulated.
| Feature | Capillary haemangioma | Cavernous haemangioma |
|---|---|---|
| Typical age | Infant (<1 yr) | Adult (30–50 yr) |
| Natural course | Grows then involutes | Slowly progressive, no involution |
| Location | Extraconal/lid (superficial) | Intraconal |
| Proptosis swells on crying | Yes | No |
| Encapsulated | No | Yes |
| Marker/clue | GLUT-1 +ve | "Filling-in" contrast enhancement |
| Treatment | Propranolol | Surgical excision if symptomatic |
Dermoid cyst
- Commonest orbital cystic lesion of childhood and the commonest space-occupying lesion of the orbit in children overall.
- A choristoma — normal tissue (skin, hair, sebaceous glands) in an abnormal location, arising from epithelium trapped along bony suture lines.
- Classic site: superotemporal orbital rim (zygomatico-frontal suture). Presents as a smooth, non-tender, mobile subcutaneous swelling that is not attached to skin.
- Imaging shows a well-defined cystic mass, often with bony fossa/scalloping; may have a "dumbbell" shape extending intra- and extra-orbitally.
- Complication: rupture causes intense granulomatous/lipogranulomatous inflammation — hence excise intact without spillage.
High-yield: A superotemporal cystic mass in a child = dermoid. A superotemporal solid mass in an adult that pushes the eye down-and-in = lacrimal gland tumour.
Rhabdomyosarcoma — the orbital emergency to know cold
- Commonest primary orbital malignancy of childhood (mean age ~7–8 years).
- Arises from pluripotent mesenchyme (NOT from mature extraocular muscle).
- Presents with rapidly progressive proptosis over days–weeks, often with lid swelling/ptosis — can mimic orbital cellulitis but lacks the systemic toxaemia.
- Typical location: superonasal quadrant (displaces the eye down and out).
- Histological types: Embryonal (commonest, best location-prognosis in orbit) > Alveolar (worst prognosis; t(2;13) PAX3-FOXO1 fusion) > Pleomorphic (adults). The orbit's relatively favourable prognosis is because tumours are detected early.
- IHC markers: desmin, myogenin (MyoD1), muscle-specific actin.
- Approach: Proptosis in a child progressing over days → urgent imaging (CT/MRI) → incisional biopsy for tissue diagnosis → chemotherapy + radiotherapy.
- Treatment principle: rhabdomyosarcoma is NOT primarily treated by exenteration; it is highly radio- and chemosensitive. Management = biopsy then chemoradiation (vincristine + actinomycin-D + cyclophosphamide, "VAC"). This is a perennial trap MCQ.
High-yield: Orbital rhabdomyosarcoma = biopsy + chemotherapy + radiotherapy, NOT exenteration as first line. Overall survival is high (>90% for localised orbital embryonal disease).
Lacrimal gland lesions
The lacrimal gland sits in the superotemporal orbit (lacrimal fossa of the frontal bone). Lesions here push the globe down and inwards (infero-nasally) and may produce an S-shaped lid (ptosis of the outer third).
Rule of halves (classic teaching): roughly 50% of lacrimal fossa masses are inflammatory/lymphoid, and 50% are epithelial. Of the epithelial group, ~50% are pleomorphic adenoma (benign) and ~50% are carcinomas.
Pleomorphic adenoma (benign mixed tumour)
- Commonest benign epithelial (and overall commonest epithelial) tumour of the lacrimal gland. Middle-aged adults (40s).
- Painless, slowly progressive (>12 months) proptosis displacing the eye down-and-in; no bone destruction — instead causes smooth bony fossa expansion/excavation on CT.
- "Mixed" because it has both epithelial and mesenchymal (myxoid/chondroid stroma) elements, with a pseudocapsule.
- Treatment = complete excision WITHOUT prior incisional biopsy. Biopsy or incomplete removal causes seeding → recurrence and malignant transformation.
High-yield: Pleomorphic adenoma must be excised intact (en bloc) without incisional biopsy — biopsy risks recurrence and malignant change into pleomorphic adenocarcinoma (carcinoma ex-pleomorphic adenoma).
Adenoid cystic carcinoma
- Commonest malignant epithelial tumour of the lacrimal gland (and the most lethal).
- Short history (<12 months), PAIN (early perineural invasion along branches of V) and often sensory loss; bone destruction on CT.
- Histology: classic "Swiss-cheese" / cribriform pattern. Basaloid subtype = worst prognosis.
- Notorious for perineural spread to the cavernous sinus and high recurrence; poor prognosis despite radical surgery + radiotherapy.
| Feature | Pleomorphic adenoma | Adenoid cystic carcinoma |
|---|---|---|
| Nature | Benign | Malignant (commonest lacrimal Ca) |
| Duration of symptoms | >12 months (slow) | <12 months (rapid) |
| Pain | Painless | Painful (perineural invasion) |
| Bone on CT | Smooth fossa expansion | Bone destruction/erosion |
| Histology | Mixed (epithelial + chondroid stroma) | Cribriform "Swiss-cheese" |
| Treatment | Excise intact, no biopsy | Radical surgery + radiotherapy |
| Prognosis | Excellent (if not seeded) | Poor |
High-yield differentiator: Painful lacrimal mass + short history + bone erosion = adenoid cystic carcinoma. Painless, long history + bone moulding/expansion = pleomorphic adenoma. Pain and duration are the examiner's favourite split.
Other lacrimal lesions
- Dacryoadenitis: acute (mumps, EBV, bacterial) or chronic. Inflammatory enlargement, S-shaped ptosis, tenderness.
- Mikulicz syndrome: bilateral lacrimal + salivary gland enlargement (sarcoidosis, TB, lymphoma, IgG4 disease).
- Orbital lymphoma: painless, "salmon-pink" subconjunctival lesion; commonly MALT-type B-cell NHL; moulds to orbital structures without bone destruction. Treated with radiotherapy ± chemotherapy.
Neural tumours (high-yield associations)
- Optic nerve glioma: child with slow axial proptosis + early vision loss + optic atrophy; strong association with Neurofibromatosis type 1 (NF-1). MRI: fusiform optic nerve enlargement, "kink" sign. Usually a low-grade pilocytic astrocytoma in children.
- Optic nerve sheath meningioma: middle-aged woman; classic triad = vision loss + optic atrophy + optociliary shunt vessels (retinochoroidal collaterals). CT shows "tram-track" calcification along the nerve sheath.
- Plexiform neurofibroma: pathognomonic of NF-1; "bag of worms" lid feel, S-shaped ptosis, may have pulsatile proptosis from sphenoid wing dysplasia.
High-yield: "Tram-track" sign = optic nerve sheath meningioma. NF-1 is linked to optic glioma, plexiform neurofibroma, and sphenoid wing dysplasia (pulsatile proptosis).
Diagnosis & investigation of choice
Stepwise workup of an orbital mass:
- History — age, duration, pain, intermittency, systemic symptoms.
- Examination — direction of proptosis, exophthalmometry (Hertel), resistance to retropulsion, RAPD, fundus for choroidal folds/optociliary shunts.
- Imaging —
- CT is best for bony involvement and calcification (dermoid scalloping, adenoid cystic erosion, meningioma tram-track, NF-1 sphenoid dysplasia).
- MRI is the investigation of choice for soft-tissue characterisation and apical/intracranial extension (optic nerve lesions, perineural spread).
- B-scan ultrasound helps for anterior/cystic lesions and vascular flow.
- Biopsy — incisional for most malignancies and lymphoid lesions; but NEVER incise a suspected pleomorphic adenoma (excise whole).
High-yield: CT = bone & calcification; MRI = soft tissue & nerve/intracranial extent. For a lacrimal fossa mass, CT bone window decides benign (expansion) vs malignant (destruction).
Management principles at a glance
- Capillary haemangioma → observe; propranolol if vision-threatening.
- Cavernous haemangioma → surgical excision if symptomatic.
- Dermoid → complete excision without rupture.
- Rhabdomyosarcoma → biopsy + chemoradiation (not exenteration).
- Pleomorphic adenoma → en-bloc excision, no biopsy.
- Adenoid cystic carcinoma → radical surgery + radiotherapy (poor outcome).
- Orbital lymphoma → radiotherapy ± chemotherapy.
- Metastasis/inflammatory pseudotumour → treat cause; pseudotumour responds dramatically to steroids.
Complications
- Amblyopia (capillary haemangioma in infancy — the most important reversible complication).
- Compressive optic neuropathy → progressive vision loss, RAPD, disc oedema/atrophy.
- Exposure keratopathy from severe proptosis and lagophthalmos.
- Choroidal folds and induced hypermetropia (posterior indentation by cavernous haemangioma).
- Perineural/intracranial spread (adenoid cystic carcinoma) and distant metastasis (rhabdomyosarcoma to lung/bone).
- Recurrence + malignant transformation of an inadequately excised or biopsied pleomorphic adenoma.
Key differentials
- Thyroid eye disease (Graves): commonest cause of bilateral (and unilateral) proptosis in adults; spares tendon insertions; inferior > medial rectus involvement (mnemonic "I'M SLow" — Inferior, Medial, Superior, Lateral order).
- Orbital cellulitis: painful proptosis + fever; the great mimic of rhabdomyosarcoma in children — distinguished by toxaemia, sinusitis source, and imaging.
- Idiopathic orbital inflammatory disease (pseudotumour): painful, steroid-responsive; may involve the lacrimal gland (mimics dacryoadenitis) or muscles (myositis with tendon involvement, unlike Graves).
- Carotico-cavernous fistula: pulsatile proptosis, bruit, dilated "corkscrew" conjunctival vessels, raised IOP.
Recently asked / exam angle
- Commonest questions: benign orbital tumour in adults (cavernous haemangioma); primary orbital malignancy in children (rhabdomyosarcoma); commonest lacrimal gland epithelial tumour (pleomorphic adenoma); commonest malignant lacrimal tumour (adenoid cystic carcinoma).
- Treatment traps: rhabdomyosarcoma → chemoradiation, NOT exenteration; pleomorphic adenoma → excise without biopsy; capillary haemangioma → propranolol.
- Image/sign recognition: "tram-track" calcification = optic nerve sheath meningioma; GLUT-1 positivity = capillary haemangioma; "Swiss-cheese/cribriform" = adenoid cystic carcinoma; "salmon-pink" patch = orbital lymphoma.
- Localisation logic: down-and-in proptosis = superotemporal (lacrimal) mass; down-and-out = superonasal (rhabdomyosarcoma/dermoid variant); axial = intraconal.
- Syndromic links: NF-1 (optic glioma, plexiform neurofibroma, pulsatile proptosis from sphenoid dysplasia); neuroblastoma metastasis with raccoon eyes in children; breast Ca metastasis with enophthalmos in adults.
- Pain + duration split in lacrimal masses is a near-annual single-best-answer.
Rapid revision
- Cavernous haemangioma = commonest benign orbital tumour in adults; intraconal, axial proptosis, "filling-in" enhancement, encapsulated.
- Capillary haemangioma = commonest in infants; grows then involutes; swells on crying; GLUT-1 +ve; treat sight-threatening lesions with propranolol.
- Rhabdomyosarcoma = commonest primary orbital malignancy in children; rapid superonasal proptosis; embryonal type commonest; treat with biopsy + chemoradiation, not exenteration.
- Dermoid cyst = commonest orbital cyst of childhood; superotemporal rim; a choristoma; excise without rupture.
- Pleomorphic adenoma = commonest lacrimal epithelial tumour; painless, >1 yr, bone expansion; excise intact, never biopsy.
- Adenoid cystic carcinoma = commonest lacrimal malignancy; painful, <1 yr, bone destruction, "Swiss-cheese", basaloid = worst; poor prognosis.
- Optic nerve sheath meningioma = vision loss + optic atrophy + optociliary shunts + "tram-track" calcification.
- Optic nerve glioma = child, axial proptosis with early vision loss, linked to NF-1.
- Lacrimal mass pushes eye down-and-in; superotemporal location → S-shaped ptosis.
- CT for bone/calcification; MRI for soft tissue and intracranial/perineural extension.
- Child + proptosis + ecchymosis ("raccoon eyes") = metastatic neuroblastoma; adult enophthalmos from metastasis = scirrhous breast Ca.
- Orbital lymphoma = painless "salmon-pink" subconjunctival mass, MALT-type, radiosensitive.