Fine-needle aspiration cytology and biopsy in hepatic masses: A minimally invasive diagnostic approach

Abstract

Aims and Objective: To evaluate the diagnostic sensitivity, usefulness and limitations of fine-needle aspiration cytology (FNAC) and fine-needle aspiration biopsy (FNAB) in the diagnosis of hepatic masses. Materials and Methods: FNAC was performed on 150 cases of hepatic masses under guidance of ultrasound or computed tomography (CT) scan. Adequate diagnostic aspirates were obtained in 147 cases (98.0%). Smears were stained with hematoxylin and eosin (H and E), and Papanicolaou stains. FNAB was obtained from the same 149 cases (except one) and stained with HE stain. The hepatic masses were categorized into benign, malignant and inflammatory groups. Results: Out of 150 hepatic masses, 3.3% were benign, 94.26% were malignant and 2% were inflammatory lesions. FNAC and FNAB were unsatisfactory for evaluation in 3 out of the 150 cases (2%) and 6 out of 149 cases (4.02%), respectively. Correct cytological diagnoses were achieved in 129 out of the 150 cases (diagnostic sensitivity: 86%). FNAB gave satisfactory results in 143 out of 149 cases (diagnostic sensitivity: 95.77%). Cytological diagnoses of 21 cases were not consistent with histology (false negativity: 14%). Cyto-histological correlation showed 87.32% diagnostic sensitivity of FNAC for malignant tumors, whereas benign tumors posed maximum diagnostic problems, with sensitivity of 40%. This difference was statistically significant (P < 0.05). FNAB showed a statistically significant difference (P < 0.05) compared with FNAC in the diagnosis of benign and malignant hepatic masses. FNAC showed 100% diagnostic sensitivity for inflammatory lesions. Conclusion: Malignant tumors of liver can be confidently diagnosed on FNAC. However, FNAC has a few limitations and diagnostic challenges in benign lesions, well-differentiated and poorly differentiated hepatocellular carcinoma, and metastatic carcinoma. Microhistology by FNAB allows architectural, cellular and immunohistochemical evaluation. To obtain maximum diagnostic information with reduction of indeterminate reports, a combined approach of FNAC and FNAB with clinical findings, tumor markers and ancillary techniques should be used.