Microcystic adnexal carcinoma: in vitro growth characteristics and effect on stromal collagen production

Microcystic adnexal carcinoma (MAC) is a locally aggressive cutaneous neoplasm, which is characterized by follicular and sweat gland differentiation and a stroma of dense collagen.

MAC cells were studied and characterized in vitro through phase microscopy and proliferation assays. Additionally, to delineate a possible role of soluble mediators in bringing about the dense stromal collagen seen in association with these tumors, the effect of conditioned media derived from the tumor cells on the level of collagen production by normal fibroblasts was examined.

A significant morphologic difference between the MAC cells and normal keratinocytes was not noted. Proliferation assays demonstrated a significantly slower rate of growth of the MAC cells in comparison to controls. Media conditioned by MAC cells did not induce an increase in collagen synthesis by cultured fibroblasts, but rather, there appeared to be an inhibitory effect on the level of collagen synthesis.

The increased stromal collagen seen in MAC histologically is not the result of growth factors or cytokines produced by the MAC cells.