Asian Journal of Research in Medicine and Medical Science

Pigments are among the most visually and diagnostically significant biomolecules present in both human and animal tissues. From the dark hues of melanin in the skin to the golden-brown tones of hemosiderin in the spleen or liver, pigments often serve as vital histological indicators of normal physiology, pathological transformation, or environmental exposure. This review synthesizes findings from recent studies conducted between 2018 and 2025 to explore the current state of histochemical pigment detection and its applications in research and clinical practice. To ensure a comprehensive, transparent, and scientifically rigorous review of histochemical studies on pigments, this work was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. An extensive literature search was performed between May and June 2025 using four major scientific databases: PubMed, Scopus, Web of Science, and Google Scholar. The search covered a publication window from January 2018 to May 2025. Boolean search operators were used in combinations such as: Pigment and Histochemistry, Melanin and histological stain, Lipofuscin and Sudan Black B, Hemosiderin and Perls stain, Tattoo ink and tissue reaction, Pigment and immunohistochemistry, Pigment detection and ("AI" OR "machine learning" OR "imaging"). All identified records were first exported into Zotero for reference management. Duplicates were removed manually. Titles and abstracts of the remaining studies were screened for relevance. Two independent reviewers then conducted full-text screening using a standardized review protocol. In cases of disagreement, consensus was reached through discussion or consultation with a third expert. A total of 198 records were initially retrieved. After de-duplication and abstract screening, 34 articles were selected for full-text evaluation. Finally, 12 studies met all inclusion criteria and were included in the review. In conclusion, pigments are far more than colored deposits on a microscope slide; they are molecular signposts that trace physiological processes, disease evolution, environmental exposure, and even cellular aging. As methods continue to improve in accuracy, speed, and objectivity, the field of pigment histochemistry will only become more integral to pathology and translational research in the years to come.