Juvenile hyaline fibromatosis: morphologic, immunohistochemical, and ultrastructural study of three siblings.

Juvenile hyaline fibromatosis (JHF) is a rare hereditary disease characterized by the deposition of hyaline ground substance, which is described as fibrillogranular material on electron microscopy. Approximately 65 cases have been reported to date in the English language literature. We add 3 new cases of children presenting with multiple subcutaneous nodules. We have described the light microscopic, electron microscopic, and immunohistochemical features of these nodules. The characteristic chondroid appearance on light microscopy is imparted by large peripheral vesicles in the stromal cell cytoplasm. Ultrastructurally, the fibroblasts have shown evidence of defective synthesis of collagen, which is then deposited as fibrillogranular material in the matrix. Immunohistochemical studies have shown CD68+ macrophages and multinucleated histiocytic giant cells in all five specimens from our 3 cases. As far as we know, the presence of giant cells has not been reported in the literature. The main purposes of this report are to highlight the presence of macrophages as a constant constituent of the stromal cells in JHF and to review the literature on this subject.