Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 9 4 2023 07 25 197 200 Fatemeh Abbasi Department of Oral Medicine, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. Zahra Pourgholi Takrami Department of Oral Medicine, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. Zeynab Bayat Department of Oral Medicine, Faculty of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. 2023 03 07 2023 06 04 Fibrosarcomas is an uncommon connective tissue growth that rises from the proliferation of malignant fibroblasts. Local recurrence is frequent, but metastasis is rare. About 0.05% of cases are affected in the head and neck. We report a case of mandibular fibrosarcoma in a 30-year-old man who presented with intraoral swelling in the ridge of the left mandibular alveolus. Histopathology showed the proliferation of malignant fibroblast cells arranged in a classic herringbone pattern. Keywords: Fibrosarcoma; Fibroblast; Malignancy; Lower jaw; Spindle cell tumor; Oral cavity. https://jcr.tums.ac.ir/index.php/jcr/article/view/431 https://jcr.tums.ac.ir/index.php/jcr/article/download/431/369