Pseudoxanthoma Elasticum-Like Papillary Dermal Elastolysis: A Case Report.

We report a clinical case of pseudoxanthoma elasticum-like papillary dermal elastolysis. A 36-year-old female presented to our institution with a 30-year history of spontaneously erupting papules on her anterior neck. These lesions had gradually increased in both number and size without any identifiable trigger. Physical examination revealed numerous densely distributed, firm, pale-yellow subcutaneous papules localized to the anterior neck, right supraclavicular region, right shoulder, and right posterior neck. Dermoscopy demonstrated pale or milky-white structureless areas with globular or irregular morphologies. Some lesions exhibited slight confluence. Focal linear or atypical vessels were observed between the lesions, but no classic frog-spawn appearance or typical vascular structures were present. Histopathologic examination of serial sections showed mild acanthosis and papillomatosis. The superficial dermis exhibited mild vascular dilatation accompanied by a sparse perivascular inflammatory infiltrate. Crucially, elastic tissue staining revealed fragmented and markedly reduced elastic fibers within the papillary dermis. Consequently, the diagnosis of pseudoxanthoma elasticum-like papillary dermal elastolysis was established.