A 40-year-old woman with a long history of rheumatoid arthritis presents with generalized enlargement of the tongue that began several years ago. What is the MOST likely cause?

Correct answer: D. Amyloidosis

• A. Mucopolysaccharidoses (Hurler, Hunter) do cause macroglossia but are inherited lysosomal storage diseases presenting in childhood with coarse facies and skeletal dysplasia — not an adult-onset complication of RA.
• B. Lymphangioma produces a localized, pebbly, 'frog-egg' surface lesion present from infancy, not a diffuse adult-onset enlargement.
• C. Hemangioma is a localized vascular lesion that blanches on pressure and is typically congenital.
• D. Correct. Chronic inflammatory disease — rheumatoid arthritis in particular — can lead to SECONDARY (AA) AMYLOIDOSIS, in which serum amyloid A protein is deposited as insoluble fibrils in tissues. The tongue is a classic deposition site, producing diffuse, firm, generalized macroglossia, often with lateral indentations. Renal deposition causing progressive kidney failure is the major systemic concern. Diagnosis: biopsy with Congo red stain showing apple-green birefringence.