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Hepatocellular carcinoma metastatic to the oral mucosa: report of a case with multiple gingival localizations.

BACKGROUND
Metastases to the oral mucosa are rare, representing less than 1% of the tumors at this site. Most of these metastatic neoplasms originate in the lungs, kidneys, and liver.


METHODS
The clinicopathologic features of an occult hepatocellular carcinoma, metastatic to the oral mucosa, are reported. The patient, a 70-year-old male, complained of 3 distinct polypoid, reddish lesions of the antero-inferior alveolar crest and both the right and left postero-superior attached gingiva, without bone involvement. The lesions were excised, with the clinical diagnosis of multiple vascular tumors, formalin-fixed, paraffin-embedded, cut and stained with hematoxylin and eosin. Consecutive sections were immunostained for alpha-1-antichymotrypsin, CEA, cytokeratins, EMA, hepatocyte antigen, PSA, S-100 protein, and thyroglobulin, using the alkaline phosphatase/anti-alkaline phosphatase technique.


RESULTS
The morphologic features of the lesions were consistent with the diagnosis of carcinoma with trabecular and glandular patterns and bile secretion; furthermore, immunohistochemical reactivity for alpha-1-antichymotrypsin, cytokeratins, CEA, EMA, and hepatocyte antigen was demonstrated and the hepatic origin of the tumor was postulated. Ultrasonography demonstrated a liver mass, which was biopsied and treated by chemoembolization. While no further complications occurred in the oral mucosa, the patient died 8 months after the diagnosis for widespread diffusion of the tumor to the lungs and brain.


CONCLUSIONS
This case emphasizes the need to include metastatic tumors in the differential diagnosis of atypical neoplasms of the oral mucosa and to evaluate the opportunity of surgical treatment in order to preserve the functions of the mouth, even if the prognosis of the primary tumors remains unfavorable.