The first case report of metastatic rectal adenocarcinoma to the oral vestibule in a young woman.

BACKGROUND

The available literature regarding metastasis to the oral cavity from colorectal cancer, especially rectal cancer, is currently limited. With this in mind, we aimed to report the first case of rectal adenocarcinoma metastasis to the oral vestibule.

CASE REPORT: A 36-year-old Caucasian female with a 17-months history of rectal adenocarcinoma and several metastases was referred to the Dental Oncology Service due to a nodular swelling in the oral cavity. Intraoral examination showed a large, painless nodule with superficial necrosis on the right side of the mandibular vestibule. An incisional biopsy was performed, and the microscopic analysis demonstrated an infiltrative tumor characterized by islands of malignant epithelial cells with a columnar appearance and tubular pattern. The epithelial component presented pseudoductal structures resemble intestinal mucosa, which exhibited intraluminal secretion. The neoplastic cells were immunoreactive for CDX2 and Cytokeratin 20, and negative for Cytokeratin 7. Therefore, the final diagnosis of metastatic rectal adenocarcinoma was established. Unfortunately, the patient died 23 months after the diagnosis of the primary tumor.

CONCLUSION

The study highlights that metastases to the oral cavity should be considered in the differential diagnosis of large reactive lesions affecting young patients, especially in the setting of a patient history of cancer.