Clear-cell adenoma is one of salivary tumors which was first reported by Corridan in 1956, but it is rarely encountered in the clinical practice.
We recently experienced a case of so-called clear-cell adenoma occurred in the palate andcould obtain its primary culture cells. This culture cells were observed by light and electron microscopes for examining the influence of anticancer agents on culture cells.
The tumor was wholly resected under general anesthesia and the patient is now in a good condition without relapse as of 4 years lapsed after operation.
Clear-cell adenoma is said to be consisted of two types of cells by electron microscope, one is rich in organella such as mitochondria, rER, and tonofilament so that it seems to have a dark cytoplasma (organella rich cells). The other has less organella with glycogen granule, fat deposit, and vacuole and seems to have a light clear cytoplasma (organella poor cells).
The primary culture cells contained much organella and round, amorphous secrete-like granule with high electron density. When anticancer agents (5-FU, MMC) were acted against these cells, secrete-like granule disappeared followed by the appearance of fat deposit-like substance which then decreased in number to form vaculoes.