Ectopic lacrimal gland tissue of the orbit and sclerosing dacryoadenitis.

A 28-year-old man with unilateral proptosis was found to have sclerosing dacryoadenitis and ectopic lacrimal gland tissue of the orbit. The unusual combination simulated invasive adenocarcinoma of the lacrimal gland both clinically and histopathologically. Based on clinical and experimental observations, we propose that the acinar gland atrophy and fibrous replacement of the lacrimal gland and of the heterotopic tissue was the result of a primary developmental abnormality associated with obstruction to normal gland outflow. Physician awareness that ectopic lacrimal gland tissue in the orbit can be affected by sclerosing dacryoadenitis is probably the most critical factor in establishing the correct diagnosis.