False-Negative Ligamentum Teres Tendon Sampling for the Detection of Systemic Amyloidosis

This case report involves a 60-year-old man with bilateral carpal tunnel syndrome, hip osteoarthritis, and lumbar spinal stenosis who underwent biopsies of the ligamentum teres, ligamentum flavum, and carpal flexor tenosynovium. Amyloid deposits were identified in the ligamentum flavum and flexor tenosynovium, but not the ligamentum teres. Amyloid was typed by mass spectrometry, cardiac scintigraphy was negative, and genetic testing remains pending. This supports that ligamentum flavum and carpal flexor tenosynovium biopsies may have better diagnostic value for the early diagnosis of amyloidosis, while the ligamentum teres is an unpredictable location of biopsy for early diagnosis.