Systemic hyalinosis (juvenile hyaline fibromatosis). Ultrastructure of the hyaline with particular reference to the cross-banded structure.

Systematic hyalinosis (juvenile hyaline fibromatosis) is characterized by hyalinized skin lesions. Electron microscopic examination of a hyalinized skin tumor from a 19-year-old man with this syndrome revealed that the hyaline was composed of ruthenium red-positive ultrastructures (granules, filaments, and a kind of cross-banded structure), indicating the presence of glycosamino-glycan or glycoprotein, and a small number of thin collagen fibrils. Using a new ruthenium red staining method combined with an enzymatic digestion procedure, it was demonstrated that the cross-banded structure and granules consisted of chondroitin sulfate-proteoglycan and/or glycoprotein, and that the cross-banded structure is probably a noncollageneous aggregate of the granules attached to the parallel-arranged filaments of hyaluronic acid-like nature.