Hand-Schüller-Christian disease occurs most frequently in children under 2 years of age. The principal manifestations of the syndrome are osseous xanthoma producing defects in the membranous bones of the skull, exophthalmos, and diabetes insipidus. The etiology is unknown, although it is generally recognized that the disturbance is related to the metabolism of lipoid material in the body. This substance accumulates in the reticulo-endothelial cells of the body either by infiltration or by some intracellular chemical change so that the affected cells are loaded with lipoid material. When this fatty substance is dissolved out and histologic study is made, the tissue cells have a vacuolated or foamy appearance (foam cells).
The clinical picture of any particular case of xanthomatosis depends upon the regions of the body invaded by these foam cells. Rowland1 contends that many other conditions such as Niemann-Pick disease, Gaucher's disease, xanthoma multiplex, and xanthomas of the skin and tendons, with or without diabetes insipidus, are all manifestations of defective metabolism of lipoids.
The tendency for these abnormal cells to accumulate in larger or smaller tissue masses produces secondary effects in various tissues of the body. In Hand-Schüller-Christian disease the localization is chiefly in the skull. When the xanthomata involve the dura mater, infiltration and lysis of the membranous bones of the skull cause circular defects of irregular contour and replacement by a fibrous, rubbery material usually containing granulation tissue, foam cells, giant cells, and scar tissue. If these abnormal reticulo-endothelial cells accumulate about the pituitary stalk, such pathologic. . .