Primary Intraosseous Squamous Cell Carcinoma

Primary intraosseous squamous cell carcinoma (PIOSCC), also known as central squamous cell carcinoma of the jaw, is a histopathologic type of primary intraosseous carcinoma. PIOSCC accounts for about 1–2% of oral cancers, and is common in the posterior dental region of the mandible, mostly occurring to middle-aged and elderly male [1–10]. Primary intraosseous carcinoma consists of three histopathologic types: salivary adenocarcinoma, odontogenic carcinoma, and squamous cell carcinoma [11–17]. Primary intraosseous squamous cell carcinoma is the most common type. PIOSCC, first reported in 1913, is a rare malignancy of jaw that may originate from odontogenic epithelial cells. The diagnostic criteria for PIOSCC are as follows: ① exclusion of the invasion of adjacent oral mucosa; ② no tumor at the site of pathological changes; ③exclusion of metastasis of malignant tumors in other parts of the body; and ④ pathological diagnosis as squamous cell carcinoma [13–15, 18–23].