Comparison of fine needle aspiration cytology needle core biopsy in the diagnosis of radiologically detected abdominal lesions

Aims: To compare the sensitivity and specificity of percutaneous fine needle aspiration (FNA) cytology and needle core biopsy (NCB) in the diagnosis of suspected intra-abdominal tumours. Methods: One hundred and forty one consecutive patients who underwent radiologically guided combined FNA/NCB of abdominal lesions over a four year period were reviewed. The diagnostic accuracy of both techniques and the value of rapid staining and assessment of cytological preparations were assessed. Results: FNA cytology and NCB identified 111 of 129 (86%) and 104 of 129 (80.6%) malignant lesions, respectively; in combination, the sensitivity increased to 90.7%. The diagnostic specificity was 100% for both methods, although one case of phaeochromocytoma was misinterpreted as undifferentiated carcinoma on biopsy. More accurate tumour subtying was possible in two cases with FNA and four cases on NCB. The series included 12 benign lesions, 11 of which and nine were accurately identified on FNA and NCB, respectively. Two specific benign diagnoses (Budd-Chiari syndrome and hepatic infarct) were made only on biopsy. The use of rapid assessment cytology preparations ensured that appropriate samples were submitted for microbiology in three liver abscesses, and provided an accurate cytological diagnosis at the time of the procedure in 103 of 141 (73%) cases. None of the patients suffered biopsy related complications. Conclusions: FNA cytology is more sensitive and accurate than NCB in the diagnosis of abdominal lesions, and also offers more rapid diagnosis. However, the combination of these sampling techniques increases diagnostic sensitivity and occasionally provides more accurate classification of tumours and benign lesions. The techniques should be considered complementary in the investigation of abdominal lesions.