Twenty-eight patients were clinically suspected of secondary amyloidosis; eight of them had abnormal results from fine-needle biopsy of subcutaneous abdominal fat. The abnormal results were later confirmed after rectal biopsy or autopsy. In addition, seven of the 19 patients with normal results also had normal results from rectal biopsies. Fine-needle biopsy of subcutaneous fat is a simple and reliable method for diagnosing secondary systemic amyloidosis.
Westermark P, Stenkvist B. A New Method for the Diagnosis of Systemic Amyloidosis. Arch Intern Med. 1973;132(4):522-523. doi:10.1001/archinte.1973.03650100040007