Ultrasound-guided percutaneous core needle biopsy of abdominal subcutaneous fat for diagnosing amyloidosis: comparison with bone marrow biopsy

Background Patients with underlying hematologic malignancy have a higher risk of developing systemic amyloidosis, which worsens their prognosis. Histopathologic detection of amyloid deposits in tissue biopsy specimens is the only diagnostic method for amyloidosis. Purpose To compare the efficacy of ultrasound-guided percutaneous core needle biopsy (USPCB) of abdominal subcutaneous fat with that of bone marrow biopsy (BMB) for diagnosing amyloidosis. Material and Methods A total of 90 consecutive patients with underlying hematologic disorders who underwent both USPCB of abdominal subcutaneous fat and BMB for suspicion of amyloid deposition during a 10-year period were included in this retrospective study. Results The sensitivity and specificity of detecting amyloid deposition were 85.7% and 100%, respectively, with USPCB as opposed to 4.8% and 100%, respectively, with BMB, and the sensitivity was significantly higher with USPCB (P < 0.001). The mean number of times USPCB was performed was 3.3. There were no major complications associated with USPCB. The sensitivity of detecting amyloidosis was not different between the 18-G needle group and the 14-G group (100% vs. 80%; P = 0.623). Logistic regression analysis revealed that acquiring more cores from USPCB and thinner fat tissues were statistically significant factors that affected the diagnostic accuracy of USPCB for amyloid detection. Conclusion The sensitivity of amyloid deposition was significantly higher with USPCB of abdominal subcutaneous fat than BMB. Acquiring more cores by multiple biopsies instead of using a larger bore needle and thin subcutaneous fat pad may be a favorable factor for the diagnostic accuracy of USPCB.