Pseudoxanthoma elasticum. A report of 5 cases in one family

Five cases of pseudoxanthoma elasticum (PXE) found in one family are reported. The hereditary pattern is probably of autosomal dominant type 2. In the fundi of all the 5 cases, mottlings of the retinal pigment epithelium or orange skin-like lesions in both eyes which are of significant diagnostic importance are seen. The fundus changes are more prominent when skin lesions are typical. Under electron and light microscope, the pathological changes of clinically typical and atypical lesions show similar characteristics of this disorder. Remarkable calcification of elastic fibers with abnormal contour and fragmentation, destruction of mitochondria of fibroblasts and a great number of mast cells leaning against fibroblasts are the chief findings in the histochemically stained specimens. The pathogenetic mechanism of this disorder is possibly dystrophy of elastic fibers with its inherent nature of being easily calcified. Involvement of autoimmune factors in the pathogenesis is quite possible.