Odontogenic myxoma is rare benign neoplasm of jaw bones which is locally aggressive and non-metastasizing. А 23-year-old male sought medical attention with complaint of progressively increasing of asymptomatic swelling to the right side of maxilla causing serious facial asymmetry. Radiological examination, CT with 3D reconstruction was performed and it was shown well-defined unusual large radiolucent mass associated with impacted teeth within the right maxillary sinus extending into the nasal cavity with expansion of both buccal and palatal cortical plate of right maxilla. The treatment of choice was a surgical tumoral radical resection under general anaesthesia with surgical extraoral approach and preservation of the nearby structures. Odontogenic fibromyxoma was the definitive histopathological diagnosis. The postoperative period was uneventful, and the patient fully recovered. Long-term surveillance is required due to the high rate of local recurrence.