Squamous carcinoma arising from the epithelial lining of odontogenic keratocysts: report of two cases and literature review.

This study aimed to report the clinical, radiographic, and histopathological features of two cases of primary intraosseous squamous cell carcinoma (PIOSCC) arising from odontogenic keratocysts (OKCs) and to review the literature. A 35-year-old woman and a 21-year-old man presented with mandibular swelling for 5 days and 4 months. Case 1 showed a multilocular radiolucency, whereas Case 2 exhibited a unilocular radiolucency; both involved the posterior mandible. Incisional biopsy confirmed OKC, followed by decompression/marsupialization. During follow-up, both lesions underwent malignant transformation. Patients received surgery and radiotherapy and remain disease-free. Among 40 PIOSCC cases arising from OKCs, males predominated (60%, n = 24), with a mean age of 44.2 ± 16.3 years. The mandible was the main affected site, and swelling, pain, and paresthesia were the most common findings. In conclusion, PIOSCC arising from OKC may resemble cysts and benign odontogenic tumors. Pain, swelling, and ill-defined radiographic margins are highly suspicious findings.