Papillary squamous cell carcinoma of the oral cavity with acantholytic and pseudovascular features.

Herein reported is a case of papillary squamous cell carcinoma (PSCC) in the oral cavity with features of koilocytosis, acantholysis and pseudovascular structure. A 73-year-old woman consulted to our hospital because of a tumor in the right mandibular gum. Physical examination revealed an exophytic papillary tumor of the right mandibular gum, and a biopsy was performed. The biopsy revealed squamous cell carcinoma. No metastases were found by various imaging techniques. Therefore, resection of the tumor and mandibular bone was performed. Grossly, the tumor was exophytic and papillary, and measured 2 × 2 × 1 cm. The mandibular bone was free from tumor invasion. Microscopically, the tumor showed exophytic papillary proliferation with fibrovascular cores and consisted of atypical squamous epithelial cells. The tumor cells showed hyperchromasia, nuclear atypia, mitotic figures, apoptotic bodies, cancer pearls, and individual keratinization. Mild stromal invasion was seen. Therefore, PSCC was diagnosed. Koilocytosis, acantholytic features, and pseudovascular features were recognized in some areas. The lateral and vertical margins are negative for tumor cells. The mandibular bone was negative for tumor invasion. The pathological diagnosis was PSCC with koilocytotic, acantholytic and pseudovascular features. The patient was healthy and free from tumor three months after the operation.