Case series of head-and-neck adenosquamous carcinoma: Role of histogenetic model in immunotherapy as a future perspective for nonconventional squamous cell carcinoma.

Adenosquamous carcinoma (ASC) is not only a rare variant of squamous cell carcinoma (SCC) but it is also an aggressive and highly infiltrating neoplasm with distinct histomorphology. Histogenetic concept in the pathogenesis of the tumor would eradicate controversies regarding the resemblance of ASC with mucoepidermoid carcinoma and adenoid SCC. Hence, we intend to present a case series of four cases of ASC in the head-and-neck region reported in a single institution in the past 10 years. Head-and-neck ASC lesions have been reported in the thyroid gland, nasal cavity, oral cavity, pharynx, and larynx. Intraoral lesions are mostly seen in the tongue and floor of the mouth, but in our case series, the most common site was the maxillary alveolus. Therapeutic approach toward nonconventional malignancies of epithelial origin should include proper analysis of the biological behavior of disease, the anatomical site, sensitivity of lesion to radiation, and systemic treatment modality. Hence, for better understanding of the behavior of lesions such as ASC, immunohistochemical analysis plays a significant role as it provides an insight into the origin and also accentuates the chances of enhanced therapeutic model for treating any such variant of SCC.