aCase 3 Answers

by Dr. Chua

This 41-year-old man is referred from another hospital because of a progressive painless right proptosis for the past 18 months. He is otherwise medically well and has no past medical history of note. Orbital CT scan performed in the same hospital is shown below.

a. Where is the location of the lesion?

In the lacrimal fossa. A well-delineated homogenous mass is seen in the superior temporal quadrant of the orbit. There is no bony or soft tissue infiltration.

b. What are the main types of lesion in this region?

Lesion in the lacrimal gland fossa can be broadly divided into neoplastic or inflammatory.

Neoplastic lesions are usually of epithelial in origin and may be benign (such as pleomorphic adenoma) or malignant (such as adenoid cystic adenocarcinoma), lymphoid neoplasms may also be either benign as in reactive lymphoid hyperplasia or malignant as in lymphoma. Inflammatory causes include dacryoadenitis, sarcoidosis, and orbital inflammatory pseudotumor.

A review of 142 lacrimal gland biopsies performed during a 25-year period by Shields et al¹ showed that 78% of lacrimal gland lesions were of nonepithelial origin and only 22% were primary epithelial neoplasms. The nonepithelial lesions included inflammation (64%) and lymphoid tumors (14%), whereas the epithelial lesions included dacryops (6%), pleomorphic adenoma (12%), and malignant epithelial tumors (4%).

The ocular examination reveals a right non-axial proptosis with the globe being displaced down and inward. The vision is normal with normal fundal examination. Ocular motility is restricted on upgaze (see below). Palpation reveals a firm mass in the superior temporal quadrant of the orbit which is non-tender.

c. What is the most likely lesion?

A pleomorphic adenoma arising from the orbital part of the lacrimal gland

This is a benign mixed tumour. The lesion grows slowly and painlessly and is usually well-tolerated by the patient. Most cases involve the orbital part of the lacrimal gland and tend to grow posteriorly. The globe is displaced downward and inward. A firm mass can be palpated in the region of the lacrimal fossa. The ocular motility problems are minor despite the size of the tumour because of the slow-growing nature of the tumour².

d. How would you manage the patient?

The lesion should be excised en bloc rather than biopsied.

A common mistake is to perform an incisional rather than an excisional biopsy. Incisional biopsy breaches the capsule of the tumour and increases the recurrence rate by as much as 10 fold when compared to excisional biopsy.

e. How would you gain access to the lesion?

Via a lateral orbitotomy. This involves cutting the supra or infra orbital edge to enlarge the operative field and allows removal of lacrimal gland tumour.

A. A S-shaped incisional line is marked along the lower eyebrow.

B. The lateral orbital rim is exposed after peeling away the periosteum.

C. Drill holes (for replacing the bone later) are made before cutting the lateral wall along the supra and infra orbital edges to remove a piece of the lateral orbital wall.

D. The lesion is exposed after removal of the lateral wall and incision of the periosteum

E. The lesion is removed en bloc.

F. The cavity is examined for any residual lesion.

G. The lateral wall is replaced and sutured using 4/0 prolene.

F. The periosteum, orbicularis and skin are closed in layer and a drain tube is left in to evacuate any intraorbital bleeding.

 

Final Diagnosis from Histology (21/10/2005):

 

Macroscopy:

A piece of firm grey brown tissue measuring 30X20X10mm. Cut surface is firm and grey white.

 

Microscopic:

Section shows lymphoid tissue with variably sized and variably shaped lymphoid follicles. Between the lymphoid follicles are small reactive lymphoctyes (staining positively with CD 20 (B cell marker) 3+ and CD 30 (T cell) 2+. Adjacent area shows lacrimal gland.

 

Impression:

Reactive lymphoid hyperplasia.

 

Reference:

1. Shields CL, Shields JA, Eagle RC, Rathmell JP. Clinicopathologic review of 142 cases of lacrimal gland lesions. Ophthalmology. 1989 Apr;96(4):431-5.

2. Stewart WB, Krohel GB, Wright JE.  Lacrimal gland and fossa lesions: an approach to diagnosis and management. Ophthalmology. 1979 May;86(5):886-95.

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