To the Editor.—
Zaynound et al1 discussed the association of satellite lesions with pyogenic granulomas following trauma or treatment. We have recently recorded experimental data relevant to the etiology and evolution of these intriguing vascular tumors. The purpose of this communication is to further analyze the origin of the "pyogenic granuloma."
Warren, Greenblatt, and Shubik2,3 employed the hamster cheek-pouch chamber to demonstrate that tumor implants induced new capillary proliferation directly in the cheek-pouch membrane and across microporous membrane filters. Folkman et al4 subsequently isolated a diffusable Tumor Angiogenic Factor (TAF), characterized as a heat labile, cryostable lipoprotein containing 25% RNA and 50% carbohydrate; this factor is directly mitogenic for capillary endothelium5,6 and stimulates the neovascularization essential for adequate nutrition of the proliferating tumor cells.In a recent study (unpublished data) we have documented the elaboration of TAF by human skin tumors, including basal cell
Wolf JE, Hubler WR. Origin and Evolution of Pyogenic Granuloma. Arch Dermatol. 1974;110(6):958. doi:10.1001/archderm.1974.01630120090030