Case Report

Peripheral osteoma of the mandible in a cat

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Abstract

A six-year-old, male, castrated domestic shorthair cat was presented for evaluation of an oral mass. Full physical examination revealed a large hard mass arising from the lateral aspect of the caudal part of the left mandible. Abdominal ultrasound and thoracic computed tomography (CT) were performed to rule out metastatic disease. In addition, CT of the skull with intravenous contrast agent was performed. Histopathological examination of extra-oral biopsies confirmed the tentative diagnosis of peripheral osteoma. A three-dimensional printed skull was used in conjunction with the CT images to determine the detailed location and extent of the mass and to identify anatomical spatial relationships with important neurovascular structures. Surgical debulking of the osteoma was performed. The cat recovered uneventfully but the mass regrew nine months after debulking therapy, sooner than expected. Nevertheless, CT scan of the skull was suggestive for regrowth of the peripheral osteoma rather than for malignant transformation. The owners did not elect to pursue caudal mandibulectomy.