Giant pleomorphic adenoma of the lacrimal gland:
pre- and post-operative function

Ajay Jain [1], Vikas Inder Nehru [1], Uma Nahar Saikia [2], C Ekambar Eshwara Reddy [1]

¹Department of Otolaryngology and Head & Neck Surgery
²Department of Histopathology
Postgraduate Institute of Medical Education and Research, Chandigarh – 160 012, India

Correspondence: Dr Ajay Jain, Senior Resident Dept. of Otolaryngology and Head & Neck Surgery Postgraduate Institute of Medical Education and Research, Chandigarh – 160 012, India. Tel: 0091-172-2746329 Email: drajayjain{at}hotmail.com
 

Accepted for publication:  December 2nd, 2004

Introduction
Pleomorphic adenoma is the most common epithelial tumour of the lacrimal fossa. In the literature only two cases of Giant pleomorphic adenoma of lacrimal gland have been reported.1,2 We describe a third case that forced the eyeball to come out of orbit to lie next to nasolabial fold. Despite this, patient had perception of light and extraocular movements present in the affected eye.

Case Reports
A 45-year female presented with left proptosis with slow diminution of vision for last 12 years. On examination, there was a swelling protruding from left orbit and displacing the eyeball out of the orbit. The globe was lying at upper end of nasolabial groove. The left palpebral fissure was widened and the bosselated appearance of the mass could be seen laterally after lifting the upper eyelid. The extra ocular movements of the globe were restricted but present in all directions. There was perception of light from the medial direction. The pupil was slightly mid-dilated, reacting to light but with an afferent papillary defect. The cornea, anterior chamber and iris were normal. There was a mature cataract.

CT showed a mixed density mass in left orbit with moderate enhancement and hypodense areas suggestive of degeneration within it. There was expansion of the orbit and reduction of maxillary sinus to a slit. Erosion of the orbital roof resulted in extradural protrusion of a part of lesion into the anterior cranial fossa. Fine needle aspiration cytology revealed a pleomorphic adenoma. The mass was excised completely by lateral orbitotomy approach. Histopathology confirmed the diagnosis of pleomorphic adenoma without any capsular infiltration. Postoperatively, the pupil reacted to light as before and perception of light was positive. At 12 months follow up, patient had redundant upper eyelid, ptosis and enophthalmos. Patient is now planned for cataract extraction and upper eyelid reconstruction.

Discussion
Pleomorphic adenoma of the lacrimal gland is usually less than 3 cm at the time of diagnosis. In the index case, the tumour was 7 ´ 6 cm in diameter thereby labeling it as Giant Pleomorphic adenoma. We are aware of only two cases of giant pleomorphic adenoma of lacrimal gland that have been reported.[1, 2] This is the only case where some vision was present which could be preserved after excision of the tumour.

It is remarkable to note that the optic nerve and extraocular muscles can withstand stretch for a very long time and yet retain function provided the lesion is benign and the stimulus very slow. Proptotic compressive effects are remedied initially by forward protrusion of the eye, thereby reducing the compressive effect within the orbit. Further proptosis and severe stretching can adversely affect the eye and compromise the function of the optic nerve. However, it has been proposed that gradual stretch applied to a nerve can lead to axonal re-organization and elongation of axonal tracts.[3] This theory may explain the persisting function of the optic nerve, as in our case, in spite of severe stretching produced by slow growth of the tumour.

A proptotic eye not adequately protected by the lids can develop exposure keratopathy. Surprisingly, this case did not have any exposure keratitis in spite of a prolonged history. This shows that the accessory lacrimal glands can compensate for loss of function in the main lacrimal gland.

References

(1) Guerra MF, Gonzalez FJ, Campo FR, de Llano MA. Giant pleomorphic adenoma of the lacrimal gland. J Oral Maxillofac Surg. 2000 May; 58(5): 569-72.

(2) Kapoor S, Sood GC, Kapoor MS, Aurora AL. Giant pleomorphic adenoma of accessory gland. Indian J Ophthalmol. 1978 Jan; 25(4): 52-3.

(3) Penn Researchers Discover That Stretching Neurons Induces Growth. Scientists foresee bridging nerve damage with grafts (University of Pennsylvania website) April 17, 2001. Available at: http://www.upenn.edu/researchatpenn/article.php?15&sci Accessed May 20, 2004.