Granular cell ameloblastoma of the mandible with metastasis to the third thoracic vertebra. A case report.

A 62-year-old housewife had a metastasis of granular cell ameloblastoma to the third thoracic vertebra. She had suffered at least four local recurrences during the 38-year duration of the right mandibular tumor and was treated by posterior decompression of the spinal cord with instrumentation. Histologically, the granular cells appeared to be of epithelial origin. Ultrastructurally, the granules were identified as lysosomes, including some that were autophagic. Of 45 reported cases of granular cell ameloblastoma, there have been only three cases with pathologically confirmed metastasis. Their characteristics are long duration of the tumor, multiple local recurrences, and predominance in blacks.