Squamous Lesions of the Neck: A Cyto-histopathological Correlational Study

Summary: Introduction: Head and neck squamous cell carcinoma (HNSCC) accounts for over 500,000 new global cases and 40,000 new cases within the United States annually. Of these, approximately 40% initially present with regional nodal involvement. Accurate diagnosis of regional nodal neck masses is critical to patient care. The purpose of this study is to assess the correlation of fine needle aspiration (FNA) cytological diagnoses to subsequent histopathological resections. Materials and Methods: A systematic search for ""neck AND squamous"" was carried out in the hospital electronic database of all cytological cases from 2018-2023. Both consultation and in-house cases were included in the study. Cytology cases were included in the study when a subsequent surgical pathology resection was identified in the electronic database. Results: Of 477 cytological cases identified, 215 patients had subsequent in-house surgical pathological resection specimens and were included in this study. Of these, 19% were female while 81% were male. The complete cyto-histopathological correlational data is presented in Table 1. In 67% of all cases, a malignant cytological diagnosis was rendered, with almost all being concordant upon resection. One discordant case with a false positive malignant cytology showed significant squamous cytological atypia (Figure 1), however upon resection it revealed a markedly inflamed brachial cleft cyst and no evidence of carcinoma. All benign cytology diagnoses had a benign follow-up in our cohort. One false negative case was identified in a non-diagnostic cytological sample with a subsequent malignant histopathological follow-up. The discrepancy was due to a sampling error in the original cytological specimen as it only showed rare anucleated squamous cells. Conclusions: Overall, the results support that cytological diagnosis of neck FNA specimens is effective in correctly diagnosing squamous lesions. Retrospective analysis of discordant cases provides a useful learning opportunity for pathologists of all levels.