Fine-needle aspiration biopsy of lytic bone lesions: An institution's experience.

Objectives: Fine needle aspiration (FNAB) is an effective, minimally-invasive, inexpensive, diagnostic technique. The objective of this study was to evaluate the accuracy of FNAB in the diagnosis of bone lesions.

Methods: FNABs of bone lesions diagnosed at our institution over a 2-year period were retrospectively analyzed.

Results: 241 samples were reviewed. Patients included 121 males and 120 females, with ages ranging from 4-95 years (mean = 66 years). Of these 241 cases, 43.2% had FNAB and 56.8% had FNAB with core needle biopsy (CNB). The cytologic diagnoses were categorized as nondiagnostic, benign, atypical, suspicious, and positive for malignant cells. Total of 84.3% of FNABs were diagnostic. Of the malignant cases, 78.5% were metastases from nonosseous primary sites, 17.1% were lymphoproliferative lesions, and 4.4% were primary bone tumors. The most common site of metastasis was the pelvic bones (43.5%) followed by the vertebral column (38.7%). Breast (21%), lung (12.7%), and prostate (11.3%) were the most common identifiable primary site in metastatic cases. FNA smears and cell blocks allowed identification of metastatic lesions in 94.3% cases with immunohistochemistry (IHC). Obtaining a concomitant CNB did not result in a statistically significant increase in overall diagnostic yields (P = .20), ascertaining presence of metastatic lesion (P = .96) or ability to identify site of primary tumor in cases of metastasis (P = .53) compared to FNAB alone. Diagnostic accuracy was improved by reviewing clinical history, performing cell block, and IHC.

Conclusions: FNAB is a reliable tool for diagnosis of bone lesions with comparable diagnostic sensitivity to CNB.