Metastatic adenocarcinoma of the colon: early manifestation in gingival tissue.

A case of gingival metastasis of adenocarcinoma of the colon is reported, the lesion being an early clinical indication of a primary malignant tumor. The diagnosis of metastatic lesion in the oral region is always challenging, both to clinician and to the pathologist, due to its rarity and complexity. In the present case, the clinical hypothesis was peripheral ossifying fibroma or pyogenic granuloma. Histologically, the biopsy tissue revealed a malignant neoplasm not connected to the mucosal surface. Immunohistochemically, the lesion was positive for 35ßH11 and cytokeratin 20 and focally positive for cytokeratin 7. Treatment involved excision of primary tumor and follow-up chemotherapy. The clinical, histological and immunohistochemical characteristics are discussed.