PACHYDERMOPERIOSTOSIS - ULTRASTRUCTURAL-S TUDY

Background. Pachydermoperiostosis (PDP) is a rare genetically determin ed disease belonging to the group of hyper trophic osteoarthropathies. Its aetiopathogenesis remains unclear. Most hypotheses favour an exog enous stimulation of fibroblasts. Methods. A clinically typical patien t with PDP was studied by electron-microscopy with particular referenc e to the dermis and its cellular constituents. Fibroblasts from involv ed skin were cultured and studied in comparison with control cells. Re sults. Remarkable modifications of the structure of the dermis were ob served, encompassing irregular caliber of collagen fibres, extracellul ar deposits of microfibrils and of amorphous granular substance corres ponding to the Alcian blue positive deposits seen by conventional hist ochemistry. The in vitro growth of fibroblasts was normal. Conclusion. Authors reviewed aetiopathogenic hypotheses. Our data suggest a gener ically determined alteration of extracellular matrix production by fib roblasts as a possible explanation for the development of PDP.