Chronic sialadenitis with marked lymphadenopathy mimicking lymphoma on FDG PET/CT.

A 53-year-old woman with bilateral proptosis and diffuse lymphadenopathy had FDG PET/CT for the evaluation of lymphoma. There were significant enlargements of the lacrimal glands, thickening of the intraorbital muscles, prominent parotid/submandibular glands, and FDG-avid lymphadenopathy in the neck, right axilla, and mediastinum. The findings were suggestive of either lymphoma or sarcoidosis. Subsequent biopsy of the left lacrimal gland revealed chronic inflammation with lymphoid aggregate formation, atrophy, and fibrosis consistent with chronic sialadenitis, and an incisional biopsy of the cervical lymph node showed salivary gland tissue with inflammation as well. There was no pathological evidence of lymphoma or sarcoidosis.