BACKGROUND: Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) often presents with cystic cervical metastasis and a small primary tumor localized in the palatine tonsils or base of the tongue, which is diagnostically challenging. Testing for HPV DNA in fine-needle aspiration (FNA) smears from metastases may facilitate a targeted diagnostic workup for identifying the primary tumor. This study was designed to assess the ability to detect HPV DNA in FNA smears with polymerase chain reaction (PCR).

METHODS: May-Grünvald-Giemsa (MGG)-stained FNA smears from metastases and corresponding surgical specimens were collected from 71 patients with known HPV-positive OPSCC, 12 patients with oral squamous cell carcinoma (OSCC), 20 patients with branchial cleft cysts, and 20 patients with Warthin tumors. Thirty-eight patients with OPSCC and 7 patients with OSCC had FNA smears available from metastases and also surgical specimens from the primary tumor and the metastases. The scraped cell material from FNA smears and corresponding surgical specimens were analyzed for HPV DNA by PCR. p16 immunohistochemistry was performed on surgical specimens from the carcinomas.

RESULTS: HPV DNA was detected in 68 of the 71 FNA smears from OPSCC metastases. All corresponding surgical specimens from primary tumors (n = 71) and metastases (n = 38) were p16- and HPV DNA-positive. All the surgical specimens and corresponding FNA smears from OSCCs, Warthin tumors, and branchial cleft cysts were HPV DNA-negative. The sensitivity and specificity were 94.7% and 100%, respectively.

CONCLUSIONS: The detection of HPV DNA in MGG-stained FNA smears by PCR is a valid method that could be implemented in routine clinical practice.