Fine-needle aspiration biopsy from subcutaneous fat. An easy way to diagnose secondary amyloidosis

Secondary amyloidosis is usually diagnosed by demonstrating amyloid deposits on histological sections by Congo red staining. An alternative method is a fine needle aspiration biopsy (FNAB) from subcutaneous fat which, in this study, was carried out on 301 patients. In order to test the efficiency of FNAB we analysed 146 patients from whom in addition to FNAB one or two histological samples including 125 oral and 65 rectal biopsies were available. FNAB proved very reliable for demonstrating secondary amyloidosis as estimated by the index of sensitivity (0.82). The corresponding figures for rectal and oral biopsy were 0.97 and 0.64 respectively. Although the rectal biopsy proved to be the best method, we strongly recommend FNAB from the subcutaneous fat as the preferred method for screening and diagnosing secondary amyloidosis.