Study on concordance of specific cytological diagnosis with histology in a teaching hospital

Background: Fine-needle aspiration cytology (FNAC), a cheap screening technique, has helped reduce the diagnostic turnaround time of palpable swellings from different anatomical sites. In light of the technique increasingly being used as a definitive diagnostic tool, it is thus important to evaluate its accuracy in making specific diagnosis beyond just being a screening tool. Objective: To determine the concordance rate between cytological and histological diagnosis Materials and Methods: Cytology and corresponding histology reports for lesions from patients with maxillofacial, lymph node, and abdominal swellings, where both were available, were compared for the concordance of specific cytological diagnosis with final histological diagnosis. Results: In the 10-year (2006–2015) studied, there were 177 complete cases in which specific diagnoses were made on cytology; of these, 135 (75.3%) were in concordance with histological diagnoses. Concordance for intra-abdominal, maxillofacial, and lymph node aspirates was 90.2%, 85.5%, and 62.9%, respectively. Cytological concordance of specific diagnosis for benign and malignant lesions was 70.7% and 79.5%, respectively. Concordances for lymphomas, carcinomas, and sarcomas were 84.1%, 68.2%, and 66.7%, respectively. The specific cytologic diagnosis was enhanced by preaspirate ultrasound scan while the absence of immunocytochemistry hampered accuracy in specific diagnosis of nodal non-Hodgkin's and Hodgkin's lymphoma (66.7% and 42.9%), respectively. Conclusion: This study concludes that FNAC is a simple technique with fairly reliable utility in proffering specific diagnosis on suitable lesions. However, in developing countries where repertoire of antibodies for immunocytochemistry may be limited, the accuracy will be improved by good clinical history and preaspirate ultrasound where necessary.