The Color of Urine: Then and now - A Comprehensive Review of the Literature with Emphasis on Intracytoplasmic Pigments Encountered in Urinary Cytology

We present a review of the significance of pigmented cells in urine cytology. The presence of intracellular pigment granules, their color, size, shape and variation in size and shape, as well as their staining reactions with special stains can provide useful diagnostic insight, especially when interpreted in the cytologic context (type of pigmented cell and its degree of atypicality) and patient’s clinical context. The main differential diagnosis of cytoplasmic pigmented granules includes hemosiderin, lipofuscin, and melanin, each having a different pathogenesis and significance. The goal of this manuscript is to describe the morphological, histochemical and ultrastructural characteristics of the pigments seen in urinary cytology, and to review the benign and malignant conditions associated with them.
Source: Journal of the American Society of Cytopathology - Category: Cytology Source Type: research