Cytogenetic and fluorescence in situ hybridization analysis of a basal cell adenocarcinoma of the mandible.

Basal cell adenocarcinoma (BCAC) of the salivary glands is rare. Distant metastasis to the mandible from a salivary gland tumor is also considered rare. The cytogenetic finding of a case of metastatic BCAC of the mandible is described. We are unaware of earlier reports regarding cytogenetic findings of BCAC either at the primary site or at a distant metastasis site. An 80-year-old female with primary BCAC of the parotid salivary gland underwent parotidectomy and chemotherapy. One year later, a metastatic lesion in the mandible was found. Tissue specimens from the mandibular lesion were tested by the following pathologic methods: hematoxylin-eosin and immunohistochemistry for CK8/18, CK/903, vimentin, and smooth muscle actin. The characteristic histologic architecture of BCAC found in the mandible was similar to that of the earlier findings of the tumor in the parotid gland. A fresh sample from the mandibular lesion was examined by cytogenetics and fluorescence in situ hybridization (FISH), using centromeric probes for chromosomes 4, 8, 10, 18, and 22. A paraffin-embedded sample of the primary tumor was also examined by FISH. Cytogenetic and FISH analyses of the mandibular metastatic lesion revealed a clone with a pericentric inversion of chromosome 17 and a clone with trisomy 4, respectively. Trisomy 4 was also found in the paraffin-embedded samples of the primary parotid tumor.