Maduromycosis of foot

There is diffuse soft tissue swelling involving the foot dorsum on the medial side. The swelling is predominantly over the metatarsal location with an extension up to the ankle region. The is mild skin redness without any sinus formation.

There are multiple, thin-walled cystic lesions in the foot dorsum. Most of the lesions are located in the subcutaneous plane of the ankle and foot regions. The ankle lesions lie between the tibialis anterior tendon and extensor hallucis longus tendon. One lesion is deep to muscle on the medial side of 1st metatarsal distal shaft. The largest lesion overlies 1st metatarsal shaft, lying medial to the extensor hallucis longus tendon; measuring about 47 x 41 x 20 mm - 21 cc. The other lesions show a size range from 3 to 15 mm. Multiple tiny (1 - 2 mm)echogenic foci are present along with fluid in the larger cystic lesions. The smaller lesions show a central tiny echogenic focus with the hypoechoic peripheral rim. There is tibialis anterior tenosynovitis extending from its myotendinous junction to its insertion level. Anterior extensor are intact. There is no foot joint effusion/ bone erosion close to the cystic lesions.

1st photo shows a gross specimen. 2nd photo shows the post debridement status of the foot.

Gross Description - a single soft tissue piece, solid-cystic, brown-white, measuring 75x 45 x 20 mm, weighing 31.0 grams. Cut surface shows a cystic cavity with yellowish fluid and granules.

Microscopic Description - Sections show acute and chronic inflammatory cells with granulation tissue, multinucleated giant cells, and granulomas. Areas of fungal cavity present with thick grains and hyphae of Eumycetoma.
Gram's stain shows negative staining. Giemsa stain shows morphology consistent with Eumycetoma. PAS and GMS stain show histology of Eumycetome - Fungal lesion. There is no evidence of actinomycosis/tuberculosis / any malignancy or other neoplastic etiology.
Diagnosis - Fungal lesion - Eumycetoma, left foot, dorsal aspect.