Labial salivary gland biopsy for diagnosing immunoglobulin light chain amyloidosis: a retrospective analysis
OBJECTIVES The aims of this study were to (1) determine the feasibility of tandem assessment of the presence of amyloid in subcutaneous abdominal fat by fine-needle aspiration and oral mucosal tissue biopsy in patients initially diagnosed with multiple myeloma (MM) and (2) determine the optimal site for detection of amyloid in the oral cavity (tongue compared with labial minor salivary glands) in the same cohort of patients. STUDY DESIGN A prospective, cross-sectional study was performed on patients with newly diagnosed MM. Subjects completed an abdominal fat pad aspirate and biopsies of both the tongue and labial minor salivary glands (LMSGs). All specimens were analyzed for presence of amyloid via standard techniques. RESULTS Eleven subjects completed the protocol. Amyloid was not detected in any abdominal fat pad specimens. Amyloid was not detected in any tongue specimens; however, 2 subjects demonstrated amyloid deposition in LMSGs. Neither of these subjects demonstrated evidence of systemic amyloidosis or recurrence of MM at least 3 years after completing the study protocol. CONCLUSIONS The results of this study suggest that the labial minor salivary glands may be the optimal site to detect amyloid in patients with newly diagnosed MM. Additional studies are warranted to determine if amyloid in the LMSGs represents a high-risk prognostic factor for MM.