Eye

Question 1

Idiopathic orbital inflammation (orbital pseudotumour) may develop concomitantly with……

Answer 1

sclerosing inflammation in the retroperitoneum, mediastinum, thyroid, especially as a manifestation of IgG4-related disease

Question 2

Most common primary ocular malignancy

Answer 2

Choroidal melanoma

Question 3

Most common benign adult orbital tumour

Answer 3

Cavernous malformation/cavernous haemangioma

Question 4

Most common cancer to metastasize to orbit

Answer 4

Breast, followed by prostate, melanoma, lung

Question 5

Enhancement of cavernous malformation/haemangioma

Answer 5

Poor arterial enhancement. Fills centripetally on venous phase imaging.
Typically intraconal.
T1 iso to muscle, T2 bright

Question 6

Imaging characteristics of orbital haemangiopericytoma

Answer 6

Extraconal. Commonly adjacent to paranasal sinuses. Lobulated and well circumscribed (if no aggressive features). Calcification rare. Marked arterial enhancement (unlike cav malfs) with rapid washout. Isointense to grey matter on T1 and T2.

Question 7

Most common primary orbital lymphoma type

Answer 7

NHL, specifically Mucosa-associated lymphoid tissue (MALT) subtype

Question 8

Differential for lacrimal gland masses (salivary gland).

Answer 8

50/50 benign/malignant

1. Epithelial:
   a. pleo adenoma/BMT (B).
   b. Adenoid cystic carcinoma (M) - pain, perineural spread, poor prognosis.
2. Non-epithelial:
   a. lymphoma (usually non-Hodgkin B cell type). May be ax with Sjogrens

Question 9

Nearly all optic nerve gliomas are …. (type of glial tumour)

Answer 9

JPA, manifesting in kids less than 8yo. Ax NF1.