Progressive Macroglossia and Dysphagia as the Initial Manifestation of Systemic Amyloid Light-Chain (AL) Amyloidosis Associated With Multiple Myeloma: A Case Report and Literature Review

Systemic amyloid light-chain (AL) amyloidosis is characterized by the extracellular deposition of misfolded immunoglobulin light chains in tissues and is often associated with plasma cell dyscrasias, including multiple myeloma. Macroglossia is an uncommon but characteristic manifestation and may rarely be the presenting feature. We report the case of a 68-year-old woman who presented with progressive tongue enlargement, dysphagia, and significant weight loss over six months. Laboratory evaluation revealed severe anemia, hypercalcemia, markedly elevated serum free kappa light chains with a profoundly abnormal kappa/lambda ratio, and an IgG kappa monoclonal protein. Because the degree of macroglossia raised concern for coexisting amyloidosis, an abdominal fat pad biopsy was performed, but it was negative. Targeted tongue biopsy subsequently demonstrated amyloid deposition, and bone marrow biopsy revealed extensive plasma cell infiltration consistent with multiple myeloma. The patient was treated with a bortezomib-based regimen (CyBorD), with daratumumab added subsequently, resulting in improvement in macroglossia, oral intake, weight, and hematologic parameters over six months. This case highlights progressive macroglossia as an important clinical clue to underlying systemic AL amyloidosis and plasma cell dyscrasia, and underscores the importance of early tissue diagnosis and prompt therapy.