Undifferentiated Pleomorphic Sarcoma of the Tongue Involving the Floor of the Mouth – A Rare Presentation

Undifferentiated pleomorphic sarcoma (UPS) involving the oral tissues is a very unusual, aggressive neoplasm often mimicking oral squamous cell carcinoma. A 45-year-old male patient presented with a painful, nonhealing ulcer on the right lateral border of the tongue extending to the floor of the mouth for 3 months. Examination revealed a 3 cm × 2 cm ulceroproliferative lesion with submandibular lymphadenopathy. Magnetic resonance imaging shows an infiltrative mass involving the tongue muscles and sublingual space. Microscopic examination revealed spindle cells with cellular and nuclear pleomorphism, with atypical mitotic figures and necrosis. The tumor cells are arranged in storiform and fascicular patterns. Immunohistochemistry confirms the diagnosis of UPS through vimentin-positive and cytokeratin-negative expression. The patient was treated with hemiglossectomy with segmental mandibulectomy and adjuvant radiotherapy (60 Gy/30 fractions). Recovery was uneventful, and the patient remained disease free at 6-month follow-up. UPS involving the oral cavity, though uncommon, requires early diagnosis and immunohistochemical evaluation for accurate diagnosis. Prompt multimodal management is crucial for improving outcomes in these rare mesenchymal malignancies.