A case of mistaken identity: the role of lacrimal gland pleomorphic adenoma tissue diagnosis

Abstract

Lacrimal gland lesions have diverse pathologies. Bone remodelling on imaging may suggest a benign lacrimal gland pleomorphic adenoma (LGPA) rather than a malignant process. The authors report a case of malignant pleomorphic adenocarcinoma, which was misdiagnosed clinico-radiologically as a benign LGPA. Lesions with bone remodelling on CT imaging were subsequently analysed amongst a cohort of 31 lacrimal gland lesions from a single tertiary centre. 31 lacrimal gland lesions biopsied over a ten-year period featured bone remodeling on CT scan, typical of LGPA. Three diagnoses were of pleomorphic adenocarcinoma. Two of these cases presented classically with unilateral painful eyelid swelling and bone destruction or bone erosion on CT scan. Seven patients (23%) in this ten-year period had bone remodeling on CT scan, typical of LGPA. Of these seven cases, three were LGPA, but the other four cases were a mixture of other diagnoses. Clinical and radiological suspicion of LGPA may be inaccurate and requires prompt histological diagnosis to facilitate appropriate further treatment and prognosis.