Immunohistochemical analysis of cancer-associated fibroblasts and podoplanin in head and neck cancer.

BACKGROUND: To immunohistochemically evaluate the association between the presence of cancer-associated fibroblasts (CAFs) and the tumour expression of podoplanin (PDPN) in head and neck squamous cell carcinoma (HNSCC) and their association with clinicopathological variables. MATERIAL AND METHODS: A tissue microarray (TMA) with biopsy sections from patients diagnosed with HNSCC was stained with antibodies against the CAFs marker, α-smooth muscle actin (α-SMA), and PDPN. We subsequently evaluated their expression to determine the association between them and with clinicopathological variables including age, primary tumour site, TNM stage, and tumour differentiation grade. RESULTS: Positive reaction to α-SMA was observed in the tumour stroma, revealing spindle-shaped cells compatible with CAFs, which showed a high expression in 62% of cases and a significant association with laryngeal carcinomas, advanced clinical stages, and lower tumour differentiation (P ≤ 0.05). PDPN staining on tumour cells showed low expression in 72% of cases, and it was not associated with any clinicopathological variable or with the presence of CAFs. CONCLUSIONS: The presence of CAFs in the tumour stroma is related to an aggressive phenotype and could increase as the disease progresses, although based on our findings, it would have no relationship, at least directly, with the expression of PDPN.

Juxtaoral organ: an anatomical finding to be considered.

The juxtaoral organ (JOO) is a vestigial anatomical structure which is not usuallydescribed in lectures and classic texts of general histology and oral histology, despiteit being included in the "Terminologia Histologica: International terms for humancytology and histology". Although there is evidence about its histological structure,there are no macroscopic anatomical reports about it. We report the finding ofa structure of glandular macroscopic appearance in a horizontal section of a plastinatedhuman head belonging to the Morphology Laboratory of the Department ofBiomedical Basic Sciences at the University of Talca. Due to its location, dimensionsand anatomical relations, we determined it to be the JOO. Using a digital calliper, wemeasured the anteroposterior and transverse dimensions of the JOO and observedits anatomical relationships with neighbouring structures of clinical relevance. Weconclude that the JOO is relevant to surgical practice due to its anatomical relationswith relevant structures such as inferior third molar and lingual nerve. Its clinicalapplication lies in the differential diagnosis with invasive processes of malignantneoplasia originating in the oral cavity.