Characterisation of the Madurella mycetomatis mycetoma granuloma tissue pigments and fibrous tissue

Abstract

Background: Mycetoma the unique neglected tropical disease, a mutilating chronic granulomatous
inflammatory infection characterised by significant deformities and disabilities. It is characterised by the
formation of brown and yellowish-brown pigments within the eumycetoma tissue granulomas, however,
the nature of these pigments is not well characterized. This study was set out to determine the nature of
these pigments.
Material & Methods: The study included 22 surgical biopsies from patients with Madurella mycetomatis
eumycetoma. The biopsies were histopathologically examined using different stains. In addition to Periodic
Acid Schiff (PAS) stain and Hematoxylin and Eosin stain, Prussian blue stain for haemosiderin identification,
Masson-Fontana stain for melanin, Sudan black B and Sudan III for lipids, long Ziehl-Neelsen (ZN) stain
for acid fast lipofuscin pigments and Masson’s trichrome for collagen fibers were used.
Results: the Madurella mycetomatis eumycetoma tissue granuloma histopathological examination revealed
two pigments; melanin and haemosiderin and collagen fibers. The dark pigment is melanin as it bleached
with potassium permanganate oxidation. the iron-containing pigment probably related to haemosiderin.
The fibrils stained with Masson’s trichrome stain strongly suggest presence of collagen fibers. Lipofuscin
pigments were not detected.