Oral Metastasis From Colorectal Adenocarcinoma: Report of a New Case and a Scoping Review.

Objectives: This study is aimed at describing an unusual case of oral metastasis from colorectal adenocarcinoma and at performing a scoping review analyzing the available literature on such cases. Materials and Methods: We present a rare case of oral metastasis from colorectal adenocarcinoma in a 37-year-old Italian woman. Clinical oral examination showed the presence of a swollen lesion in the vestibular gingiva of the right mandibular region, associated with Grade III mobility of the second premolar. Radiographic examination revealed a radiolucency apical to the first molar and second premolar associated with the rhizolysis of these teeth. Furthermore, we conducted a scoping literature review of the PubMed, Web of Science, and Scopus databases in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews (PRISMA-ScR) guidelines. Results: The second premolar was extracted, and an incisional biopsy of the osteolytic lesion was performed for histological and immunohistochemical examination, which revealed an adenocarcinoma fragment with mucinous characteristics and a morphology and immunophenotype compatible with caudal-related homeobox transcription factor 2 (CDX2) and cytokeratin (CK) 20. In conclusion, the lesion was indicative of oral metastasis from colorectal adenocarcinoma. Furthermore, the review of the existing literature in the English language yielded 112 cases of oral metastases from colorectal adenocarcinoma, which were included in our analysis. Conclusions: Although oral metastasis from colorectal adenocarcinoma has been reported previously, it is a rare manifestation. Clinical Relevance: Because of the rarity of oral metastasis and possible variations in the clinical and histological presentations, correct diagnosis can be challenging and requires careful clinical and histopathological evaluations with adjuvant immunohistochemical studies.