Pleomorphic adenoma in the palpebral lobe of the lacrimal gland

Head and neck surgeons commonly manage tumors, lesions, and diseases in and around the orbit. Lesions of the lacrimal gland account for 5% to 15% of all primary orbital tumors.1 Pleomorphic adenomas comprise 25% of all lacrimal gland tumors and 50% of all epithelial neoplasms involving the lacrimal gland.1-3 Pleomorphic adenomas arising in this location are typically slow-growing, painless lesions that require en bloc excision to avoid tumor seeding into the orbit.1 The lacrimal gland consists of 2 lobes separated by the levator aponeurosis: a deep orbital lobe and a superficial palpebral lobe. While pleomorphic adenomas of the lacrimal gland are commonly located in the orbital lobe, tumors that originate in the palpebral lobe are far less common.2-4 While originally thought to be extremely rare,2 in a review of 36 epithelial lacrimal gland neoplasms, Vangveeravong et al reported that 17% arose from the palpebral lobe.4 However, upon publication of this manuscript, only 14 cases of pleomorphic adenoma involving the palpebral lobe had been reported.4 To our knowledge, this is the first such case reported in the otolaryngology-head and neck surgery literature. The purpose of this article is to present a patient with a lacrimal gland mass involving the palpebral lobe and to describe the importance of en bloc excision in the management of these lesions. Additionally, we emphasize the utility of an anteriosuperior orbitotomy approach via an eyelid-crease incision in the treatment of superficial superior orbital masses. A 20-year-old Asian female was referred from psychiatry for evaluation of a left lacrimal gland mass noted on magnetic resonance imaging (MRI) of the brain. The mass had been asymptomatic, and the patient denied any change in vision or lacrimation. There was no proptosis, and the lesion was painless. Facial examination showed no visible evidence of lesions or masses. Extraocular eye muscles were intact bilaterally and pupils were equal, round, and reactive to light. Palpation of her left upper eyelid revealed a 1.0- to 1.5-cm mass just below the superior orbital rim in the area of her left lacrimal gland. Neck exam showed no evidence of adenopathy, masses, thyroid nodules, or thyroid enlargement. Multiplanar, multisequence MRI of the brain had been performed before and after the administration of intravenous gadolinium. This study had been ordered to rule out organic causes of psychosis. A well-circumscribed left lacrimal gland mass was incidentally noted. The lesion showed high signal intensity on T2 and low signal intensity on T1. The lesion enhanced homogeneously (Fig 1). T2-weighted MRI of the head demonstrates a well-circumscribed mass in the left anterolateral orbit. After counseling the patient about these findings, surgical excision was recommended. The planned procedure was complete surgical excision by anterosuperior orbitotomy without bone removal. Through a small curvilinear upper eyelid incision, tenotomy scissors were used to dissect through the orbicularis oculi muscle and orbital septum. The levator aponeurosis was identified and incised, allowing for visualization of the tumor within the palpebral lobe of the lacrimal gland. The tumor was resected by taking a small cuff of lacrimal gland tissue around the mass itself. Grossly, the specimen consisted of a 1.0-g, 1.6 × 1.2 × 0.7-cm tan nodule with a relatively smooth external surface with focal fibrous adhesions. The specimen was submitted en bloc, and frozen-section diagnosis revealed pleomorphic adenoma. Final histopathologic examination (Fig 2) confirmed a pleomorphic adenoma encased within a fibrous pseudocapsule. Normal lacrimal gland tissue was adjacent to the tumor, and the surgical margins were negative. These tumors are of epithelial origin, and the three classic cell types seen in pleomorphic adenomas were present. The abundant background of a myxoid matrix is seen surrounding duct formations lined with a layer of cuboidal epithelial cells. This epithelial layer is covered by a myoepithelium of columnar cells with clear cytoplasm. The tumor composition is varied with alternating areas of hypercellularity and hypocellularity. Histologic analysis (hematoxylin-eosin stain; magnification 20×, 100×) revealed normal palpebral lobe lacrimal gland (PL) with adjacent pleomorphic adenoma (PA). Glandular ducts (G) are surrounded by abundant myxoid matrix (M). Each duct is lined by cuboidal epithelium (E) and columnar myoepithelium (Me). The immediate postoperative period was without complication. At 6-day, 1-month, and 6-month follow-up appointments, she has continued to do well. There have been no postoperative problems noted, and at 6 months physical examination demonstrated a faint, well-healed 1.5-cm upper eyelid scar. Previously, all reported cases of neoplasms arising from the palpebral lobe were pleomorphic adenomas. However, Vangveeravong et al demonstrated that a variety of tumors may arise from the palpebral lobe including carcinoma in pleomorphic adenoma, carcinoma ex pleomorphic adenoma, and adenoid cystic carcinoma.4 Furthermore, slow-growing masses involving the anterolateral or superficial orbit may be clinically misdiagnosed. Pathology commonly confused with pleomorphic adenomas of the lacrimal gland includes cavernous hemangioma, schwannoma, dermoid cyst, or sebaceous cyst.2 As in the evaluation of any head and neck lesion, a complete differential should be considered, including non-neoplastic diseases of the orbit that can displace the lacrimal gland such as pseudotumor, benign lymphoid hyperplasia, lymphoma, and sarcoid.1 Malignant tumors cannot always be distinguished from benign orbital masses. Therefore, complete excision of these lesions within the pseudocapsule is recommended. Incisional biopsy or subtotal resection can result in the seeding of tumor cells into the orbit and a higher rate of recurrence. MORATORIUM on Case Reports Due to the extremely large number of case reports submitted to Otolaryngology-Head and Neck Surgery, the Journal is declaring a moratorium on those submissions, starting January 1, 2005, and lasting at least six months. Any case reports received during that time will be returned to the authors. We have been fortunate to be able to attract an ever-increasing number of Original Research articles, and with expedited online submission and review, are still reducing the time from submission to publication. Due to the large numbers of these articles, however, there are fewer case reports published in each issue. In order to provide timely review and publication to all papers, including previously submitted case reports, we are forced to issue this moratorium. We regret any hardship this action may cause to prospective authors, and urge you to send your Original Research articles to us for consideration. We remain committed to publish all case reports that have already been accepted for publication, and appreciate your patience. Thank you for your support of Otolaryngology-Head and Neck Surgery and of the American Academies of Otolaryngology-Head and Neck Surgery and Otolaryngic Allergy.