Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive variant of squamous cell carcinoma arising in various anatomical sites. This article describes a case history of BSCC of the floor of mouth with mandibular involvement, and further discusses the appropriate management of such case with reference to the literature review. A 52-year-old male patient was referred to our clinic from another university hospital. Segmental mandibulectomy with supraomohyoid neck dissection and mandible reconstruction with left fibular free flap under general anesthesia was performed, followed by radiotherapy. Histopathological examination on the tumor lesion revealed features of squamous cell carcinoma with comedo-type necrosis. A diagnosis of BSCC was given by the oral pathology specialist. Basaloid squamous cell carcinoma (BSCC) is a biphasic variant of SCC with both basaloid and squamous cell histology. A recent report showed that there is no significant difference in the prognosis. Due to the lack of accumulated research, close follow-up and continuous research are deemed necessary. Treatment that focuses on the stage of the tumor is appropriate. A periodic follow-up observation is also very important due to the occurrence of distant metastasis to the lungs.

A case of a distinctive variety of basalαd squamous cell carcinoma (B8CC) of the floor of mouth is described Histologic evaluation of the tumor showed lobules and aggregates of medium-sized basaloid cells with distinctive periph eral palisading and focal areas of comedo- necrosis. This appearance together with microcystic spaces simulated that of an adenoid cystic carcinoma. Accompanying epithelial dysplasia of the overlying mucosa was found. Immunohistochemistry of the tumor revealed diffuse strong expression for cytokeratin AE1/3, focally positive for Epithelial Membrane Antigen in the inner cells of tubular structures However, CEA, 8-100, smooth muscle actin, and vimentin were negative. The histologic differential diagnosis considered were adenoid cystic carcinoma and adenosquamous cell carcinoma Immunohistochemistry and awareness of this unusual pattern of B8CC will facilitate the correct diagnosis being reached.