Exogenous Ochronosis as an Elastotic Disease: A Light-Microscopic Approach.

BACKGROUND: Exogenous ochronosis (EO) is a deposition disease associated with application of hydroquinone-containing preparations. Characteristic ochronotic bodies (OBs) arise from endogenous connective tissues, most often reported as collagen. We highlight a significant role for elastic fibers as a precursor tissue.

OBJECTIVE: To evaluate elastic tissue pathology in EO, specifically as it relates a precursor role in ochronotic body formation.

METHODS: In this retrospective observational study, a literature review using PubMed/MEDLINE database was conducted to ascertain the most commonly ascribed precursor connective tissue. Eleven histopathologic cases of EO were identified. Patient demographics and clinical characteristics were recorded. Slides were reviewed for the presence and grade of solar elastosis (SE), the relationship of OBs to elastotic material, the presence of elastotic fibers transitioning to OBs, and positivity of bodies with Verhoeff-van Gieson elastic tissue stain.

RESULTS: Elastic fibers are uncommonly reported as the major precursor tissue of OBs. SE was uniformly present in our cases, and the majority demonstrated heavy/high-grade elastosis. Elastotic fibers transitioning to OBs were observed in all cases, and the bodies demonstrated Verhoeff-van Gieson positivity.

LIMITATIONS: Small sample size.

CONCLUSIONS: Ochronotic body formation is associated with SE, and bodies appear to arise from damaged elastic fibers.