Papanicolaou stain may not be necessary in majority of head and neck fine-needle aspirations: Evidence from a correlation study between diff-quik-based onsite diagnosis and final diagnosis in 287 head and neck fine-needle aspirations

Fine-needle aspiration (FNA) is a useful tool for immediate assessment of palpable lesions, especially in the head and neck region. The objective of this study is to evaluate the degree of correlation between Diff-Quik-based onsite diagnosis (OD) and final diagnosis (FD) and further improve the efficiency of FNA practice. Two hundred and eighty-seven cytopathologist-performed FNAs from the head and neck region were evaluated. Number of passes, number and type of slides and correlation (agreement, modified final diagnosis and disagreement) between OD and FD were evaluated. Among 287 FNAs, the average number of passes per FNA case was 2 (range, 1-5&.rpar;). The mean number of slides reviewed per case was 5 including 2 Diff-Quik (D-Q)-stained slides, 2 Papanicolaou (Pap)-stained slides, and 1 cell block (CB)/1 cytospin (Cy). 247 of 287 (86%) cases showed agreement between OD and FD. FD on 36 out of 287 cases (12.5%) was slightly modified or refined after reviewing additional slides. A major diagnostic discrepancy was noted in four cases (1.5%), three of which were classified as squamous cell carcinoma on final diagnosis, and confirmed on surgical follow-up. Accurate diagnosis can be achieved in the majority (86%) of head and neck FNAs based on immediate examination of D-Q stained slides alone. In a small number of cases (12.5%), reviewing additional slides may refine the final diagnosis. In rare cases, especially cystic squamous lesions, Pap-stained slides appeared to be helpful. It is plausible to use D-Q-stained slides alone with most head and neck FNAs in order to provide more cost effective and efficient triaging and patient management. Diagn. Cytopathol. 2010;38:846-853.