Metastatic Head and Neck Squamous Cell Carcinoma: Cytomorphological Spectrum on Fine Needle Aspiration Biopsy Cytology and Its Relevance.

Background: Head and neck squamous cell carcinoma (HNSCC) frequently metastasizes to the cervical lymph nodes and is subjected to fine needle aspiration biopsy cytology (FNABC). The aim of this study was to describe the cytomorphological spectrum and explore the association with the primary site of origin and the short-term outcome following radiation therapy.

Methods: A retrospective cytomorphological evaluation was performed on 338 cases of metastatic squamous cell carcinoma to cervical lymph nodes from HNSCC primaries. The clinical details including the age, sex, primary site of origin confirmed on histopathology, composite stage, and outcome at 1-year follow-up (86) were obtained from the records. An exploratory analysis was performed to derive any association of the cytomorphological features with the primary site of origin and short-term outcome.

Results: The patients' age ranged from 28 to 89 years (mean, 56.6 years) with marked male preponderance, and the majority in Stage IV. The primary site was the oral cavity (45.2%) followed by the oropharynx (37%), hypopharynx (8.5%), nasopharynx (6.2%) and larynx (3.1%). Cytomorphology revealed keratinization of any degree in 86% of cases. The background was necroinflammatory, fluidy, or reactive lymphocytic with granulomatous reaction in 5% of cases. The chromatin pattern (vesicular, coarse or dense hyperchromatic), presence of nucleoli, and reactive lymphocytic background showed site-specific differences. However, no cytomorphological parameter showed any association with short-term outcome.

Conclusion: Metastatic HNSCC to the cervical lymph nodes presents a broad cytomorphological spectrum with no specific association with outcome.