Squamous odontogenic tumor: A case report

Abstract

Introduction: Squamous odontogenic tumour (SOT) is a rare benign odontogenic tumour composed of well-differentiated squamous epithelium in a fibrous stroma. The aim of this report is to describe a case of SOT located between the mandibular incisors. Details: A 31-year-old man was referred for evaluation of a mandibular lytic lesion detected in a routine radiographic exam. On intraoral examination, no color mucosa alteration, swelling, hypoestesia, hyperestesia or anesthesia of gingival tissue were observed. Panoramic radiography revealed a unilocular radiolucency located at the apex of the lower incisors, which presented sharp margins and measured about 3.0 cm in diameter. Although the teeth involved were displaced, they responded positively to a cold pulp test. The differential diagnosis included ameloblastoma, keratocystic odontogenic tumor, simple bone cyst and central giant cell lesion. Under local anaesthesia, an incisional biopsy was performed. Microscopically, the lesion was composed of islands of benign neoplastic squamous epithelium in a mature connective tissue stroma without the presence of peripheral columnar cells, palisading nuclei, or stellate reticulum. According to the microscopic findings, a diagnosis of SOT was established. Surgical excision was performed under local anaesthesia, confirming the diagnosis of SOT. After 12 months of the treatment, no radiographic or clinical evidence of recurrence was observed. Conclusion(s): Although a slow growing painless swelling is the most common symptom in patients with SOT, this lesion may be a finding in a routine radiographic exam. Relevance: Radiographic exam is essential to complement the extraoral and intraoral exams, since several bony lesions may be evidenced occasionally, such as this SOT.