Sarcomatoid squamous cell carcinoma of the mandible: Radiologic–pathologic correlation and diagnostic pitfalls of an aggressive osteolytic lesion

Abstract

Sarcomatoid squamous cell carcinoma (SSCC) of the mandible is an exceptionally rare and highly aggressive malignancy characterized by biphasic epithelial and mesenchymal differentiation. Its unusual presentation and overlapping imaging features with other odontogenic and primary bone tumors make diagnosis particularly challenging. Radiologic-pathologic correlation is therefore essential for accurate identification. We report the case of a 60-year-old woman presenting with rapidly progressive right mandibular swelling. Computed tomography (CT) demonstrated an ill-defined, aggressive osteolytic lesion centered in the mandibular body, with extensive cortical destruction, cortical breakthrough, and heterogeneous enhancing soft-tissue components extending into adjacent spaces. These imaging features suggested a high-grade malignant process but remained non-specific, raising a broad differential diagnosis including primary bone sarcomas and aggressive odontogenic tumors. No definitive radiologic features of matrix mineralization or periosteal reaction were identified. Histopathological examination revealed a biphasic malignant tumor composed of conventional squamous cell carcinoma and spindle-shaped sarcomatoid components. Immunohistochemical analysis showed co-expression of cytokeratin AE1/AE3 and vimentin, confirming the diagnosis of sarcomatoid squamous cell carcinoma. No histopathological evidence of lymph node metastasis was identified. Given the locally advanced stage, the patient was treated with concurrent chemoradiotherapy following multidisciplinary tumor board discussion. This case highlights the key imaging features of mandibular SSCC and underscores important diagnostic pitfalls related to its non-specific osteolytic presentation. It emphasizes the critical role of multimodal imaging and radiologic-pathologic correlation in differentiating this rare entity from other aggressive mandibular lesions, thereby facilitating timely and appropriate management.