Most Palpebral Pleomorphic Adenomas Are Well-Defined, Outside Orbital Rim

Care should be taken to preoperatively recognize palpebral pleomorphic adenomas to avoid inadvertent incisional biopsy, according to research results published in Ophthalmic Plastic and Reconstructive Surgery. 

To report on the characteristics and management of patients with palpebral pleomorphic adenoma of the lacrimal gland, researchers reviewed patient records from 1978 to 2019 at the Moorfields Eye Hospital. Demographics, clinical features, and treatment outcomes were used to conduct a retrospective case-note review. 

The cohort of patients included 43 patients (58% men; mean age, 46 years) who presented with symptoms presented for a mean of 31 months (median, 18 months; range, 1 month to 204 months). The most common symptom was a painless upper eyelid lump, noted in 86% of patients; 9% experienced localized aching. Other symptoms included eyelid swelling and ptosis and episodic epiphora (14% and 2% of patients, respectively). Ninety-one percent of patients presented with a clearly palpable, “moderately-mobile, very firm mass,” while the remaining patients demonstrated lid swelling with “a less-defined enlargement of the lacrimal gland.” Three patients (7%) had ptosis. 

Researchers reviewed imaging in 35 patients, none of whom demonstrated globe displacement, orbital lobe enlargement, or lacrimal gland fossa expansion. Eighty percent of patients had a well-defined extraorbital mass present at the lacrimal gland anterior pole. Magnetic resonance imaging (MRI) showed extraorbital mass with low T1 and high T2 signals, as well as patchy Gadolinium enhancement. 

Five patients underwent incisional biopsy before referral, where all tumors were removed intact. Definitive surgery and histopathology confirmed intact pesudocapsule of compression in 91% patients, mild chronic lymphocytic inflammation in the pseudocapsule and/or the neighboring lacrimal gland in 23% of patients, and nests of squamous differentiation within the adenoma in 12% of patients. 

The most common postoperative complication was mild keratitis sicca, requiring long-term topical lubricants, experienced by 12% of patients. Two patients experienced persistent, untroublesome mild ptosis, and 1 had mild restriction of abduction with diplopia on extreme gaze. The average follow-up in 39 patients was 44 months (median, 11.6 months), and no patient experienced recurrent tumor during this follow-up period. 

“This study confirms prior reports of imaging, with [palpebral pleomorphic adenomas] having a well-defined mass outside the orbital rim, without expansion of the lacrimal gland fossa, and most being homogenous on [computed tomography] and MRI,” the research shows.

“They [palpebral pleomorphic adenomas] should be identified preoperatively to ensure intact excision and avoid curettage or incisional biopsy—the latter carrying a long-term risk of recurrence and malignant transformation.”

Reference

Vahdani K, Rose GE. Palpebral pleomorphic adenomas of the lacrimal gland. Ophthalmic Plast Reconstr Surg. 2021;37(2):125-128. doi:10.1097/IOP.0000000000001682.