Reading between the layers: early histopathological findings in exogenous ochronosis.

Exogenous ochronosis (EO), although rare, is a well-known pigmentary disorder. Being extremely difficult to treat, early identification is very important, with histopathology remaining the gold standard in diagnosis. A 66-year-old woman presented with periocular and lateral neck blue-gray pigmentation, who after workup including history, physical examination, and skin biopsy was diagnosed with EO based on early histopathologic findings. Classically, banana-shaped collagen fibers are considered the pathognomonic histopathologic sign; however, we present this unique case to illustrate the early findings of EO including basophilia of the collagen fibers in the upper dermis, homogenization and swelling of the collagen bundles, and altered texture and arrangement of elastic fibers in the dermis resembling solar elastosis.