Epithelial Tumors of the Lacrimal Gland

Abstract

Space-occupying lesions of the lacrimal gland and its fossa constitute approximately 5-13% of orbital masses upon biopsy (Shields et al., Arch Ophthalmol 102: 1606-1611, 1984; Reese, Trans Ophthalmol Soc UK 91: 85-104, 1971; Kennedy, Trans Am Ophthalmol Soc 82: 134-157, 1984). Based primarily on Reese's (Am J Ophthalmol 41: 3-11, 1956) 1956 clinicopathologic survey of 112 consecutive expanding lesions of the lacrimal gland, most authorities generally report that approximately 50% of the lesions originate from epithelial elements of the lacrimal gland and 50% are of nonepithelial origin (Font and Gamel, Adenoid cystic carcinoma of the lacrimal gland: a clinicopathologic study of 79 cases. In Nicholson DH (ed). Ocular pathology update. Mason, New York, pp 271-275, 1980; Goder, Orbit 1: 91-96, 1982; Rootman, Diseases of the orbit: a multidisciplinary approach. JB Lippincott, Philadelphia, pp 384-405, 1988). Of nonepithelial lesions, 50% are lymphoid tumors and 50% are comprised of various infections and inflammatory conditions. Among the epithelial tumors of the lacrimal gland, approximately 50% are pleomorphic adenomas (benign mixed tumors), 25% are adenoid cystic carcinoma, while the remaining tumors are composed of other types of carcinoma. Information from clinical history, physical examination, and diagnostic imaging, including ultrasonography, computed tomography, and magnetic resonance imaging, form the foundation in determining which category of disease the lacrimal gland tumor belongs. Proper differentiation between lacrimal gland neoplasms is of paramount importance as several of the lesions are life-threatening. The intent of this chapter is to review the clinical characteristics, pertinent diagnostic and pathologic features, biological behavior, and conventional management protocols for the more common epithelial lacrimal gland tumors. A new treatment paradigm for adenoid cystic carcinoma will also be highlighted, as well as the basic science research underlying the advances in the development of targeted anticancer therapies.