Localized cutaneous argyria from an acupuncture needle clinically concerning for metastatic melanoma.

Localized cutaneous argyria presenting as an asymptomatic blue-gray macule has been rarely reported from diverse etiologies including occupational exposures, topical medications, alternative medical therapies, body jewelry, and dental procedures (amalgam tattoos). The lesions often are clinically indistinguishable from blue nevi and malignant melanoma. We present a case of localized cutaneous argyria from an acupuncture needle in a patient with a history of malignant melanoma. Fine granules of nonbleachable dark particles coating collagen and elastin fibers, altered yellow-brown collagen bundles similar to ochronosis, and involvement of eccrine structures were histologically consistent with the pseudo-ochronosis pattern of localized cutaneous argyria, demonstrating that clinicopathologic correlation is of crucial importance.