2343. Comparison of Fine Needle Aspiration and Core Needle Biopsy Technique in the Diagnosis of Lipomatous Lesions
Authors * Denotes Presenting Author
  1. Nikki Okwelogu *; University of California San Francisco
  2. Rina Patel; University of California San Francisco
  3. Kevin McGill; University of California San Francisco
Needle biopsy is useful in making decisions regarding the treatment and management of soft-tissue tumors. Many studies have suggested core needle biopsy (CNB) to be more accurate than needle aspiration (FNA), however, none have compared their accuracy in lipomatous lesions specifically. The aim of this study was to compare the diagnostic accuracy of FNA and CNB for the diagnosis of lipomatous lesions identified on cross-sectional imaging.

Materials and Methods:
Biopsies of fat-containing tumors performed between 2010 and 2020 were reviewed retrospectively and categorized by method of tissue acquisition including FNA, CNB, or combined FNA/CNB. The results of subsequent surgical excision were used as a reference standard. Only lesions which were both sampled and subsequently surgically excised at the same institution were included. The clinic notes and pathology reports were reviewed to assess the concordance of the samples with the excised lesions and their utility in guiding treatment decisions.

54 lesions in 47 different patients met the inclusion criteria including 41 FNAs and 13 CNB or combined FNA/CNBs. While all of the CNBs were adequate to guide subsequent treatment, 24% of the FNA-only biopsies required a separate surgical biopsy prior to excision (p<0.05). 100% of CNBs were diagnostically concordant to pathologic analysis from surgical excision, compared to only 59% of FNAs (p<0.05). No complications were observed with any biopsy.

FNA and CNB are frequently used to investigate suspicious soft tissue lesions. The findings of this study suggest that CNB is more effective than FNA for initial evaluation of lipomatous lesions due to the higher accuracy of diagnosis and the lower percentage of lesions that require an additional surgical biopsy prior to treatment. Using CNB instead of FNA for initial evaluation of lipomatous lesions may expedite accurate diagnosis and avoid the need for subsequent incisional biopsy.