Pachydermoperiostosis (primary hypertrophic osteoarthropathy): report of a case with evidence of endothelial and connective tissue involvement.

A case of pachydermoperiostosis characterised by the presence of finger clubbing, periostosis, sweating of hands and feet is described. Modifications of capillaroscopic pattern and of arteriovenous anastomoses are reported. The periungual border and finger tip tissue showed diffuse endothelial hyperplasia, hyalinosis, and sclerosis with packing of collagen fibres. Electron microscopy showed hypertrophic and activated endothelia (numerous and hypertrophic Golgi complexes, several Weibel-Palade bodies, vesicles of micropinocytosis, and glycogen particles), the basal membrane thickened and reduplicated, perivasal infiltrate in superficial derma, reticulation and segmentary reduplication of basal membrane in arteriovenous shunt. In the perineural connective tissue numerous Luse bodies (long spacing collagen) were evident. The data indicate that in the early phase of pachydermoperiostosis morphological endothelial and collagen fibre abnormalities are present, though there is a normal peripheral blood flow.