Concordance of breast fine needle aspiration cytology interpretation with subsequent surgical pathology: An 18-year review from a single sub-Saharan African institution.

Abstract

There are many merits to fine needle aspiration cytology (FNAC) in evaluation of palpable breast lesions. We set out to determine the concordance of breast FNAC interpretation with subsequent surgical pathology in the resource-limited healthcare setting of rural Kenya. African Inland Church Kijabe Hospital electronic pathology files were retrospectively reviewed from 1/1999-9/2017. All breast FNAC cases and subsequent surgical pathology specimens were identified. FNAC interpretations were categorised according to the International Academy of Cytology Yokohama codes: insufficient; benign; atypical favour benign; suspicious favour malignant; and malignant. Surgical pathology results were categorised as benign or malignant. In total, 695 breast FNACs were identified. A total of 219 (31.5%) had subsequent surgical pathology. Average patient age was 39years (range 13-88); 95% were female. Nearly all (98%) lesions were palpable. FNAC interpretive categorisation was as follows: 20 (9%) insufficient, 103 (47%) benign, 16 (7%) atypical, 24 (11%) suspicious and 56 (26%) malignant. On histopathology, there were 141 (64%) benign cases and 78 (36%) malignancies (Table1). The sensitivity of FNAC for detecting malignancy was 85%; specificity was 75%. Positive and negative predictive values were 69% and 88%. Diagnostic concordance between FNAC and histopathology was 79%. For definitively diagnostic FNAC categories, diagnostic concordance was 89%. On histopathology, malignant diagnoses were given in 0 insufficient, 12 (12%) benign, 4 (25%) atypical, 11 (46%) suspicious and 51 (91%) malignant cases. There were five false-positive cytopathology interpretations and 12 false-negatives. FNAC remains a valuable tool in evaluation of palpable breast lesions in resource-limited healthcare settings.