Necrosis of pleomorphic adenoma of the lacrimal gland with acute and chronic arteriolar occlusion.

Pleomorphic adenoma of the lacrimal gland (PALG) is a benign neoplasm typically presenting with gradual, painless globe displacement and/or lid swelling. We report an atypical case of PALG in a 53-year old male presenting acutely, mimicking orbital cellulitis. Imaging demonstrated an extraconal rim-enhancing soft-tissue lesion medial to the left lacrimal gland, involving superior rectus and levator palpebrae superioris. Surgical excision and histopathology revealed PALG with central infarction, necrosis, and chronic and acute pseudocapsular arteriolar occlusion. These findings correlated with the fluctuating symptoms and suggested a multifactorial mechanism involving both underlying vasculopathy, thrombosis, and tumor growth. Infarction in PALG may occur iatrogenically or from spontaneous tumor infarction, and can cause an acute inflammatory presentation. We discuss unique histopathologic features of necrotic PALG and mechanisms of infarction. Recognition of these features and the varied presentations of PALG is crucial for proper diagnosis. Complete resection is necessary to prevent recurrence or malignant transformation.