Case 171. Madura foot (45 y-o M)
    Excision of fistule-forming inflammatory nodule at the ankle of a Japanese man with a history of canine bite 25 years earlier    
Key words : Madurella grisea, madura foot, mycetoma, grain
Fistula formation is evident in the inflammatory nodule (gross findings).   Cut surfaces of the surgically removed nodule. Black granules (grains) are seen in the center of xanthogranulomas. Extensive fibrosis is seen between the granulomas (gross findings).
Demarcated granulomas are formed in the subcutaneous tissue. The center of the granulomas shows abscess formation and contains black-colored grains (HE, low power).   Higher powered view of the demarcated suppurative granuloma containing black grains (HE). The grain consists of pigmented hyphae and matrix (Splendore-Hoeppli material).
The pigmented hyphae forming a clump secrete pigmented grain matrix. Foreign body giant cells surround the grain (HE, high power).