SummaryPrimary oral leiomyosarcomas are exceptionally rare lesions often associated with poor prognosis. We report a case of leiomyosarcoma arising in the anterior mandibular gingiva, which is a non-prevalent site of occurrence. Clinically, the tumor was far from being firm and solid as it is usually described in the literature. Light microscopy failed to confirm the true nature of the lesion on the biopsy specimen.were free but the under surface of the lesion was infiltrating the bone. A complete workup followed, consisting of CT scans (face, neck, chest), upper and lower abdomen ultra sound and a skeletal scanning. The investigation proved negative for lesions elsewhere in the body. Consequently, the patient underwent a wider excision and a peripheral mandibulectomy, preserving the continuity of the mandible, since a partial mandibulectomy was denied by the patient. A split thickness skin graft was used to cover the inner surface of the lower lip and the anterior floor of the mouth. The post-operative period was uneventful. The histopathology report indicated both free soft (confirming the previous report) and hard tissue margins. The surgical ablation was followed by radiotherapy in another institution and according to their files the patient received 66 gray (Gy) locally in 33 fragments and 52 Gy in the neck in 26 fragments. Six months postoperatively the patient presented with osteoradionecrosis of the jaw, a pathologic fracture of the mandibular symphysis and edema of the lower lip. At that time, biopsies were taken, with negative results. The patient refused admission as well as the scheduled hyperbaric oxygen therapy; simultaneously, underwent a complete CT workout (brain, face, neck, chest, upper and lower abdomen), that was negative for pathology (LMS or colon adenocarcinoma). Two months later the IntroductionBenign smooth muscle tumors, or leiomyomas, are common, well-circumscribed neoplasms that can arise from smooth muscle cells anywhere in the body, but are encountered most commonly in the uterus [1]. Leiomyosarcomas (LMS), theirs malignant counterpart, comprise 7% of head and neck sarcomas [2]. Primary LMSs rarely occur in the oral and maxillofacial region, probably due to paucity of smooth muscle tissue in the area [1,3]. Source of smooth muscle in the oral cavity may be the arterial tunica media, lingual duct, circumvallate papillae and pluripotential mesenchymal cells [1]. We present a case of oral LMS which exhibits an uncommon clinical appearance in a non-prevalent site and which also presents difficulties in the histopathologic diagnosis of the incisional biopsy. Case ReportAn 81-year-old Caucasian female attended the outpatient department, complaining of a painless mass in the region of her anterior mandibular ridge, causing difficulty in mastication. On examination the mass measured 4x3x3cm, was bluish-red in color, soft and friable in consistency and boss elated in appearance. The lesion was broad-based and firmly attached to the underlying tissues. The patient was partially edentulous an...