Benign lymphoepithelial lesion

Overview
Benign lymphoepithelial lesion is a type of benign enlargement of the parotid and/or lacrimal glands. This pathologic state is sometimes, but not always, associated with Sjögren's syndrome.

Historically, bilateral parotid and lacrimal gland enlargement was characterized by the term Mikulicz's disease if the enlargement appeared apart from other diseases. If it was secondary to another disease, such as tuberculosis, sarcoidosis, lymphoma, and Sjögren's syndrome, the term used was Mikulicz's syndrome. Both names derive from Jan Mikulicz-Radecki, the Polish surgeon best known for describing these conditions. Today, the terms "Mikulicz's disease" and "Mikulicz's syndrome" are viewed as ambiguous and outdated.

Locations
Occurring in 80% of cases, the gland most likely to be affected is the parotid gland. Lacrimal glands are also affected.

Characteristic
Benign lymphoepithelial lesion is most likely to occur in adults around 50 years of age. There is a predilection for gender with 60% - 80% being female. The gland affected has a diffuse swelling. The swelling can be asymptomatic, but mild pain can also be associated.

Most cases of benign lymphoepithelial lesions appear in conjunction with Sjögren's syndrome. When Sjögren's syndrome is present, the swelling is usually bilateral. Otherwise, the affected glands are usually only on one side of the body.

In most cases, a biopsy is needed to distinguish benign lymphoepithelial lesions from sialadenosis (sialosis).

Histology
There is a marked lymphoplasmacytic infiltration. Lymphoid follicles surround solid epithelial nests, giving rise to the 'epimyoepithelial islands', that are mainly composed of ductal cells with occasional myoepithelial cells. Excess hyaline basement membrane material is deposited between cells, and there is also acinar atrophy and destruction.

Treatment
Treatment usually consists of surgical removal of the affected gland. Prognosis is usually good, however occasionally this condition may evolve into lymphoma, or represent occult lymphoma from the outset.