Other causes of proptosis
 

A patient with a left frontal mucocle causing downward  displacement of the globe and proptosis. A patient with a right lacrimal tumour causing the globe to be displaced downward and nasally. Note the failure of right upgaze.

. There are several conditions apart from thyroid eye disease that can cause unilateral proptosis. The proptosis may be axial  when the lesion arises from the muscle cone (such as glioma and meningioma of the optic nerve and cavernous haemangioma)  or non-axial (when the lesion arises from without the muscle cone). The patient has a R/L proptosis which is aixal/non-axial (described in which direction the globe is displaced). The exophthalmometer measurement is _____mm in the right eye and ______mm in the left eye. Additional examination: palpate along the orbital margin and note any masses (such as lacrimal gland) palpate the globe to see if it is pulsatile (caroticocavernous fistula) or can be pushed back (suggestive of orbital varix) get the patient to blow the nose and note if the proptosis increases (increased proptosis can occur with orbital varix) Other examination: check the optic nerve function check the ocular motility .

Questions:

1. What is the differential diagnosis of a swollen mass in the lacrimal fossa?

Answer
Congential
dermoid
Acquired
infection
inflammation such as sarcoidosis
neoplastic causes such as metastatic tumour, lymphoma, pleomorphic adenoma and adenoid cystic carcinoma

2. What are the features of a cavernous haemangioma?

Answer
It is a round, encapsulated, well circumscribed tumour which is unilateral.
The typical age of onset is in the 40s.
Histologically, the vascular wall has multilaminar smooth muscle resembling a venous tumour.
It is slowly progressive and causes proptosis. Malignant transformation is rare.
Patient may experience decreased vision due to choroidal striae or change in the refraction due to shortened axial length from the compression.
CT scan usually shows little contrast enhancement due to its poor vascular supply.

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