Histopathological Significance of Yellow-Brown Banana-shaped Bodies

Ochronosis refers to dermal deposition of ochronotic pigment and occurs in endogenous (alkaptonuria) and, far more commonly, exogenous settings. The exogenous form is associated with prolonged use of topical hydroquinone, phenolic, and resorcinol-based agents, and various benzene-derived or occupational chemicals. Clinically, lesions present as blue-gray to brown-black dyschromia over photo-exposed sites. Histopathologically, both forms show homogenization and degeneration of collagen with characteristic yellow-brown, curved “banana-shaped” ochronotic bodies in the superficial to mid-dermis [Figure 1]. These deposits may be interstitial or peri-adnexal. The morphology on routine hematoxylin and eosin is usually diagnostic; special stains are not required. Under polarized light, the deposits may show weak birefringence, which can help delineate them from background elastosis but is supportive rather than essential.Figure 1: Skin biopsy showing ochronotic bodies in the superficial to mid-dermis, hematoxylin and eosin, 100×Histopathological differentials/mimickers include the following: • Exogenous drug-related pigmentation (minocycline, antimalarials, and amiodarone)—granular, noncurvilinear. • Argyria—fine black granules along basement membranes/adnexae, lacking curved bodies. • Tattoo pigment, heavy metal deposits, ochre granuloma, and other exogenous materials—morphologically distinct and non-banana-shaped. • Advanced solar elastosis—can mimic collagen degeneration but never produces ochronotic bodies. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.