Atypical imaging characteristics in patients with epithelial tumors of lacrimal gland and impact on initial surgical planning

Bita Esmaeli, Tracy Lu, Leena Ketonen, J. Matthew Debnam

Precis Approximately one-quarter of lacrimal gland masses present with imaging findings not consistent with standard teaching for benign vs. malignant; it is prudent to do gross total resection in such cases if eye-sparing surgery is possible. Background Epithelial lacrimal gland tumors are rare. The initial surgical decision to do an incisional biopsy vs. gross total resection depends largely on the radiologic characteristics of the lacrimal gland mass. Occasionally, the reported radiologic features attributed to benign vs. malignant lacrimal gland tumors do not hold. In this report, we will focus on these atypical presentations to help the orbital surgeon with better surgical planning. Methods Epithelial lacrimal gland tumors diagnosed in 101 consecutive patients (59 adenoid cystic carcinomas, 24 other carcinomas, and 18 pleomorphic adenomas) and treated by the primary author were included. The clinical and radiologic records were retrospectively reviewed. The clinical parameters analyzed included age, gender, histologic type, and surgical treatment. The radiologic data analyzed included radiologic characteristics of the lacrimal gland mass on the initial magnetic resonance imaging (MRI) and/or computed tomography (CT) at presentation. Cases that did not follow the “standard” imaging characteristics of carcinoma or pleomorphic adenoma were further analyzed. Results Overall, two possible atypical radiologic patterns were identified: (1) 11 of 59 (19%) cases of adenoid cystic carcinoma and 5 of 24 (21%) cases of other carcinomas were identified where the lesion was round and well-circumscribed, lacked a posterior extension or other aggressive features, and could not be distinguished from pleomorphic adenoma but after surgical resection were found to be adenoid cystic carcinoma or other types of lacrimal gland carcinoma; (2) 5 of 18 (28%) cases of pleomorphic adenoma presented with large multilobular masses and could not be distinguished from a carcinoma but in fact were found to be of benign nature on histologic evaluation. Conclusions Our findings suggest some overlap in radiologic features between pleomorphic adenomas and lacrimal gland carcinomas. Given the risk of multifocal benign or malignant recurrence of pleomorphic adenomas if excised incompletely, it seems prudent to err on the side of gross total resection for most well-circumscribed lesions of the lacrimal gland that lack aggressive radiologic features. Some of these well-circumscribed lesions will end up being adenoid cystic carcinoma or other types of lacrimal gland carcinomas upon pathologic evaluation of the surgical specimen and may require additional treatments.