Evidencing the presence of merkel cell polyomavirus in papillary thyroid cancer.

Merkel cell polyomavirus (MCPyV) infects most people asymptomatically, but recent reports indicate that the virus may be related to carcinogenesis. This study aimed to evaluate the impact of MCPyV on the development of papillary thyroid cancer (PTC). Totally, 1057 samples, including 412 fresh biopsy samples (FBS) and 645 paraffin-embedded PTC biopsy samples (PEBS), and 1057 adjacent non-cancerous samples were assessed for the presence of MCPyV DNA and RNA. MCPyV DNA was positive in 215 (20.3%) of samples, including 126 (30.6%) in FBS and 89 (13.8%) in PEBS. In MCPyV-positive samples, the mean MCPyV copy number was higher in the patients with FBS (2.3 × 10-1 ± 0.5 × 10-1 copies/cell) compared to PEBS (0.7 × 10-4 ± 0.1 × 10-4 copies/cell) and adjacent non-PTC normal samples (0.3 × 10-5 ± 0.02 × 10-5 copies/cell), indicating a statistically significant difference (P < 0.001). The LT-Ag RNA expression was higher in FBS compared to PEBS, while VP1 gene transcript was not detected in any samples. Although our findings showed the presence of MCPyV in a subset of PTC Iranian patients, further research is required to confirm these findings.

Mixed HPV-related Neuroendocrine Carcinoma and HPV-related Squamous Cell Carcinoma of the Base of Tongue in a Patient With Incidental Identification of Synchronous Metastatic Papillary Thyroid Carcinoma.

BACKGROUND: While it is not uncommon in patients with head and neck cancer to present with multiple metachronous primary neoplasms, rarely do these present as a singular mass composed of intertwined, histologically distinct malignant tumors. Sometimes referred to as collision tumors, these entities are poorly understood and only appear in a handful of case studies in the literature. CASE REPORT: Here we present a 58-year-old male diagnosed with a human papillomavirus-related collision tumor consisting of oropharyngeal squamous cell carcinoma and small-cell neuroendocrine carcinoma, as well as an incidentally discovered metastatic thyroid papillary carcinoma, despite an unremarkable thyroid gland. The patient underwent transoral robotic base-of-tongue resection and partial pharyngectomy with selective neck dissection followed by chemoradiotherapy. At the 18-month follow-up the patient was doing well. His thyroid was normal and no recurrent or metastatic carcinoma was identified on the computed tomography and positron-emission tomography/computed tomography imaging findings. CONCLUSION: To the best of our knowledge, this is the first such case in English literature. This case demonstrates the importance of tumor morphology and immunohistochemical testing in HPV-related oropharyngeal carcinomas, despite the overall good prognosis of such tumors, due to the possibility of synchronous or colliding primary neoplasms.

Detection of Human Papillomavirus in Papillary Thyroid Carcinoma and its Association with Tumor Staging and Pathologic Features.

Background: The role of human papillomavirus (HPV), as a common infection, has been evaluated in many cancers such as the cervix and squamous cell carcinoma of the head and neck. To the best of our knowledge, for the first time, the association of HPV with papillary thyroid carcinoma (PTC) and its pathologic features are investigated. Methods: A retrospective cross-sectional study was conducted from May 2014 to January 2018 in several hospitals affiliated to Shiraz University of Medical Sciences, Shiraz, Iran. Thyroid tissue specimens of patients diagnosed with PTC (n=82) and benign thyroid nodules (n=77) were collected using the consecutive sampling method. The presence of HPV in PTC, adjacent normal tissue, and benign thyroid nodules was evaluated using the polymerase chain reaction (PCR) method. The frequency of HPV positivity in PTC tissues was compared with benign thyroid nodules and adjacent normal tissue. Association of pathologic features of PTC with HPV positivity was also investigated. Data were analyzed using SPSS version 21.0, and P values less than 0.05 were considered statistically significant. Results: HPV PCR positivity was observed in 3.8% of benign thyroid nodules and 13.4% of PTC samples but in none of the adjacent normal tissues. After adjustment for age and sex, the prevalence of HPV PCR positivity in the PTC tissues was significantly more than the benign thyroid nodules (P=0.015). The prevalence was also significantly higher than the adjacent normal tissues (P<0.001). Conclusion: There was a significant association between PTC and HPV positivity. Further studies are required to determine the cause and effect of the association between these two conditions.