THE MADUROMYCOSES 



212; 



maduromycoses, to which they are, however, not confined. Their 

 exact nature is unknown, but they are probably in some way due 

 to the fungus. 



On inspecting the upper part of the cellular mass, it will be 

 observed that the white fibrous tissue increases in amount, but is 

 still loose and contains many cells in its meshes, while more 

 externally, and situate at the top of the photograph, is seen the 

 denser and less cellular connective tissue, which is continuous with 

 that separating one fungal mass from another and surrounding the 

 whole tumour. In this connective tissue, cells containing yellowish 

 granules are frequently observed. 



There are also many lymph spaces and bloodvessels, but the 

 latter at times show signs of endarteritis or periarteritis, by which 

 means the lumen of the vessel may be considerably diminished or 

 even closed. 



Very rarely do the fungi invade the body, and rise to a general 

 infection. 



The peculiarity of the pathology is the slight reaction which the 

 body makes against the invasion by the fungus, and the entire 

 absence of any attempt at repair. 



The black varieties of mycetoma owe their colour to a dark 

 substance which the fungi secrete. The nature of this black sub- 

 stance is not known. It is soluble in hot sulphuric acid, forming a 

 yellowish-red solution, but is not soluble in cold sulphuric acid nor 

 in potash solutions. According to Thudichum, it does not contain 

 haemoglobin in any form, though a small quantity of iron is present. 



In more advanced cases the swollen foot shows nodules and 

 openings externally, the latter of which lead into the sinuses. In 

 sectionizing the foot it will be noticed that the sinuses which run in 

 various directions are communicating, and end in smaU cavities 

 containing pus and the fungus, and that these cavities are embedded 

 in degenerated tissue and debris. 



The bone may or may not be affected, but if it is, the whole foot 

 can be easily cut by a knife. 



Microscopically the tissues show degeneration and debris, with 

 fibrous tissue formation, endarteritis, and periarteritis, and at times 

 absorption of the bone. 



The microscopical examination of sections of the tissues typically 

 affected — viz., of alveolar appearance — and containing mycotic 

 grains, show a central roundish mass — the mycotic grain — a clear 

 circular space, and the surrounding degenerated tissues. The clear 

 space is due to the fact that the thin purulent matter in which the 

 granule is embedded contracts during fixation with alcohol. The 

 mycotic granule is composed at the centre almost exclusively of 

 mycelial elements with a few leucocytes; more externally there are 

 masses of amorphous substance, staining lightly purphsh with eosin, 

 in which a few mycelial threads may be seen. The periphery shows a 

 polymorphonuclear infiltration. The walls of the alveolar cavities 

 containing the granules are formed of young connective tissue with 



