A 62-year-old man diagnosed in September 2003 radiologically by CT scan of a stenosing tumour of the sigmoid colon with metastases in regional lymph nodes and liver (stage IV). Endoscopic biopsies were taken of the neoplasm, the diagnosis of which was intestinal adenocarcinoma. It was considered unresectable and was treated with a palliative shotgun colostomy in the transverse colon and first-line chemotherapy with FOLFOX protocol (oxaliplatin-5-fluorouracil-leucovorin). He was re-evaluated after 6 cycles, showing tumour stabilisation, and at the end of 12 cycles tumour progression was observed with distant lymph node and adrenal metastases. In March 2004, the patient presented with mandibular pain and swelling of 3 weeks' duration, and a vegetating tumour was observed in the right anterior mandibular gum. A cervical CT scan showed a solid lesion in the right hemimandible eroding bone, 4 cm in diameter, compatible with gingival neoplasia, without lymphadenopathy. A biopsy was performed, showing a neoformation independent of the surface mucosa, which was composed of atypical, irregular glands of variable shapes and sizes, with a columnar lining and abundant mitoses. Using immunohistochemistry techniques, the tumour was positive for cytokeratin (CK) 20 and CEA (carcinoembryonic antigen), and negative for CK7, which led to a diagnosis of metastatic adenocarcinoma highly compatible with intestinal origin. He received 4 cycles of second-line chemotherapy according to the FOLFORI protocol (CPT11-5 fluorouracil-leucovorin), and gingival analgesic radiotherapy, with disease progression and progressive deterioration being observed, and exiting 9 months after diagnosis of the gingival metastasis. No necropsy was performed.