Orbit tumours including lacrimal gland CASE 1 Mass

Orbit tumours (including lacrimal gland)

CASE 1 Mass in supero-temporal orbit Painless proptosis

Lacrimal gland Well defined, lesion

Neoplastic glands embedded in a fibro (pink) -myxoid (blue) matrix

Ducts are composed of bilayer of benign epithelium (inner epithelium and outer myoepithelial)

Chondromxoid matrix

DIAGNOSIS ?

Benign pleomorphic adenoma Commonest benign lacrimal gland tumour. Orbital lobe usually-painless Frank bone invasion not present. Can become malignant Shouldn’t really biopsy-can seed and recur. Psuedo-encapsulated. Can transform into carcinoma.

CASE 2 Painful superotemporal orbital mass.

Swiss cheese appearance. Smoothly rounded sheets of deceptively Bland basaloid cells, containing round pools of mucin that mimic glands

Tumour on both sides of pink lacrimal gland capsule = infiltration=malignant

Adenoid cystic carcinoma 2 nd most common epithelial lacrimal gland tumour Malignant Perineural invasion-therefore painful Various histological patterns Adenoid-’gland like’ bacause not true glands. The mucin pools develop after stroma is pinched off from outside. Poor prognosis

For Lymphoma (Maltoma) See conjunctival session-exactly the same appearance

CASE 5

HISTORY § CHILD WITH PROPTOSIS

Spindle cells in loose matrix, with scattered deep pink larger cells.

Strap-like larger pink cells

Cells positive for Muscle marker Desmin.

Tumour nuclei positive for Muscle transcription factor Myo. D 1

Rhabdomyosarcoma (embryonal type) Sarcoma Arise from pluripotential mesenchymal cells Commonest malignant orbital tumour of childhood Muscle marker positive Electron microscopy shows striations (can see on light microscopy sometimes) and Z bands. Immunohistochemistry detects muscle proteins-Desmin and My. OD 1 transcription factor. After biopsy-chemo and radiotherapy usually 95 % 5 y survival for embryonal subtype.

Other one…. . Alveolar rhabdomyosarcoma § Nests of smaller round blue cells, with central discohesion. Peppered with some larger cells with pink cytoplasm. § Has 1: 13 or 2: 13 specific and diagnostic cytogenetic translocation § Worse prognosis than embryonal

DISCOHESION

A note on orbital tumours § Adult-commonest primary-non-Hodgkin’s lymphoma. § Kids-commonest primary-rhabdomyosarcoma. § Other tumours in orbit: Adults-Primary orbital tumours: liposarcoma, malignant peripheral nerve sheath tumour, solitary fibrous tumour. Remember metastatic carcinoma. § Children-primary alveolar soft part sarcoma. Metastatic tumours commoner: neuroblastoma, leukaemia, Ewing’s sarcoma, Wilm’s tumour are commoner ones (Jerry and Carol Shields series).

CASE 6

HISTORY § 8 YEAR-OLD CHILD § REDUCED UNILATERAL VISION § FUSIFORM SWELLING OF OPTIC NERVE

Normal Optic nerve

ABNORMAL OPTIC NERVE

Expansion by tumour showing process bearing cells

Process bearing cells alternating with fibrous areas containing intense pink bodies called Rosenthal fibres

DIAGNOSIS ?

Optic nerve pilocytic astrocytoma Unilateral visual loss and proptosis First 2 decades of life. NF-1 association Fusiform swelling of ON Confined by dura Extends through optic foraman to chaism. Cells, with many long delicate fibres, with more fibrous areas containing Rosenthal fibres. Cystic areas. Tumour often involves subarachnoid space-cardinal features. Rosenthal fibre = collections of alpha-beta crystalline. Slowly growing tumour-hardly ever fatal.

CASE 7

HISTORY § 40 YEAR OLD WOMAN § UNILATERAL VISUAL LOSS § PROPTOSIS § IMAGING SHOWS MASS AT SPHENOID RIDGE

Tumour composed of bland spindly cells With occasional foci of dystrophic calcification

Cells assume whorls

Bland Interlacing spindle cells Bland=do not look cytologically malignant

DIAGNOSIS?

Meningioma Mostly benign Optic nerve sheath OR Sphenoid wing origins Many patterns-but classicial is whorls of meningothelial cells, +/-psammoma bodies (calcification arranged as concentric circles-like rings of a tree) Arise from arachnoid cells Female bias Express progesterone receptors Associated with NF-2