Basal cell cystadenoma of the lacrimal gland: diagnostic pitfalls of a basaloid pattern in lacrimal tumours.

An 85-year-old male experienced a painless swelling along the left lateral orbit for one year. A computed tomography scan demonstrated a cystic mass in the orbit adjacent to the lacrimal gland. There was a concern for malignancy considering the large size and the patient's age, so the tumour was excised. Histopathology of the tumour showed nests with basaloid patterns, but a definitive diagnosis was not rendered. The uncertainty of tissue diagnosis coupled with the basaloid pattern, which carries a grim prognosis in some salivary gland tumours, led us to refer this case to an authority on lacrimal gland pathology, who suggested that this tumour be called a basal cell cystadenoma. To the best of our knowledge, a basal cell cystadenoma of the lacrimal gland has not been reported in the literature. We present histopathological features that distinguish this tumour from malignant tumours with a basaloid pattern. We also discuss the management differences associated with basaloid patterns in lacrimal tumours.