Labial salivary gland biopsy in the diagnosis of Sjögren’s syndrome

Introduction. Labial salivary gland biopsy is used for diagnosis of Sjögren’s syndrome (SS) and lymphoma accompanying SS. Aim. The aim of this study was to present the main techniques used for taking labial salivary gland biopsies in the diagnosis of SS with respect to their advantages, histologic criteria, validation, complications, and their usefulness for diagnostic procedures, monitoring disease progression, and treatment evaluation. Material and methods. This study is based on analysis of literature. Results. The microscopic confirmation of SS is based on the presence of focal lymphocytic sialadenitis (FLS) with a focus score ≥1 per 4 mm2 of glandular tissue. A lymphocytic focus is defined as a dense aggregate of 50 or more lymphocytes adjacent to normal-appearing mucous acini in salivary gland lobules that lacked ductal dilatation. Other histopathological features of SS are lymphoepithelial lesions and a relative decrease of <70% IgA + plasma cells. Labial salivary gland biopsy is characterized by high specificity, a positive predictive value, and an average sensitivity of 79% in SS. Conclusion. It can be also valuable in diagnosing B-cell mucosa-associated lymphoid tissue (MALT) lymphomas but it is not recommended for the monitoring of SS progression and the effectiveness of the treatment. Persistent lower lip hypoesthesia is the most severe complication of labial salivary gland biopsy.