The above specimen is a vertical section through a foot suffering from mycetoma, with the toes at the top of the specimen and the heel at the bottom. Mycetoma is an infection of the skin that has spread into the underlying bones and tissues. It can affect any part of the body, but is most commonly seen in the feet. It is sometimes known as ‘Madura foot’, as the disease was first described in the Southern Indian province of Madura. It can be caused by either fungi (eumycetoma) or bacteria (actinomycetoma) that live in soil or water which enter the skin through minor injuries and then grow in the tissues and bones of the feet, and so it is most commonly seen in agricultural workers especially those that walk barefoot.
This specimen shows fungal mycetoma, but the pathology is similar for both the fungal and bacterial variations. It begins with firm masses of fungi or bacteria appearing under the skin, resembling tumours which begin painlessly, but grow into large oozing sores. Without treatment, the fungus can, over a number of years, invade the underlying bone causing the formation of sinuses that exude a granular pus. The specimen shown is typical in that much of the area where we would expect to see the bones of the foot has been replaced with sinuses –large round spaces within the tissue. These contain some remains of decalcified bone, the loss of which would produce the pus and discharge. The contemporary notes suggest that, over the course of ten years a small white patch on the sole of the foot of the individual developed into the pathology seen in the specimen. .
Mycetoma is endemic in tropical regions, particularly in countries that lie in the ‘Mycetoma belt’ between the latitudes of 15° South and 30° North. Incidence is higher in males than females, but all age groups can be affected. Because it develops slowly, diagnosis often doesn’t occur until the disease is quite advanced, and antifungal medicines are often only partially effective, leaving amputation as the only treatment. Wearing shoes or sandals and washing the hands and feet regularly in areas where mycetoma is endemic is generally considered the best way of reducing incidence of the disease.