Mycetoma

This 47-year old man presented with a 5- to 6-year history of an enlarged left foot with occasionally draining nodules. The foot had been lacerated 12 years earlier during a cattle loading incident.

What's your diagnosis?

KEY WEST, FLA. -- Madura foot (mycetoma) occurs in tropical and temperate zones worldwide. It is rare in the United States, occurring in the southwestern states of Texas, New Mexico, Louisiana, and Florida. The most common form is caused by Pseudallescheria boydii. The saprophytic soil fungi invade the skin and subcutaneous tissue vial local trauma. Mycetomas tend to spread, progressively involving and destorying connective tissue and bone.

Clinical manifestations include a primary lesion described as a painless papule that ruptures with drainage of serosanguineous material containing characteristic grains, and formation of sinus tracts. Eventually, the area becomes enlarged nodular, discolored, and deformed.

Gross examination reveals puts containing visible granules. Hematoxylin and eosin staining reveal suppurative and granulomatous inflammation with numerous fungal hyphae. Older lesions may show fibrosis between abscesses.

In this case, reported by Dr. Lisa D. Hitchins at the annual meeting of the South Central Dermatologic Congress and Southeastern Dermatologic Association, the injury occurred about 12 years earlier. An animal stepped onto his left foot while he was loading cattle into trailer while wearing sandals, lacerating the sole near the insteap. The lesion was slow to develop, and the foot enlarged several years later.

Physical exam revealed a grossly enlarged left foot with dorsal hyperpigmentation. Nodules were present throughout the lesion, but no active discharge was noted. A verrucous plaque was present medially. No lymphadenopathy or additional lesions were found. No sinus tracts were present.

Cultures for bacteria, acid-fast bacilli, and deep fungus were negative. X-ray revealed lytic changes in the tarsal and metatarsal bones. Histopathology revealed angiodermatitis.

The patient was incaracerated at the time of the initial visit and refused to return to the clinic for further work-up since his release. A bone biopsy had been planned, with follow up hospitalization for intervenous antibiotics/antifungals.

COPYRIGHT 2001 International Medical News Group
COPYRIGHT 2001 Gale Group