AMELOBLASTOMA WITH METASTASES IN A CHILD - LIGHT MICROSCOPIC AND ELECTRON-MICROSCOPIC FINDINGS

A case of a 5 1/2 years old boy with a plexiform ameloblastoma of the jaw is reported. 6 years after resection of the primary tumor metastases developed in a lymph node at the left side of the neck and in both lungs. Thoracotomy revealed many small metastases spread all over the lungs. Light and electron microscopical studies of the primary tumor showed a typical plexiform ameloblastoma without signs of malignancy. In the metastases, however, these studies revealed the histological criteria of a malignant tumor with marked pleomorphism of tumor cells, increase of heterochromatin, enlargement of nucleoli and invagination of nuclear membranes. After enucleation of two metastases and therapy with cytostatic agents for several months no further metastases have been observed within a period of 6 years. Comparative light and electron microscopic studies of both primary tumor and metastases demonstrate that there are no histological criteria to identify the primary tumor as a malignant ameloblastoma. Ameloblastoma with distant metastases is a rare tumor in children, this case is only the third reported in the literature. © 1979 Springer-Verlag.