What opportunistic fungus is clinically and histologically similar to Aspergillus?

Patients with prolonged neutropenia, especially leukemia patients, are susceptible to infections with Fusarium. In this patient population, Fusarium species are the second most common pathogenic mold. Fusarium is a filamentous mold found in soil and plants. Inhalation into the lungs is the primary route of infection; however, primary cutaneous infection from indwelling catheters may occur. The lung is the usual site of infection; however, 75% of patients have hematogenous spread with a predilection for the skin and sinuses. The cutaneous lesions caused by Fusarium are similar to aspergillosis. The typical presentation is a painful erythematous nodule with central ulceration and necrosis. Cellulitis and onychomycosis have also been reported. Histologically, the two are identical (septate hyphae with acute angle branching). The treatment of choice is amphotericin B and the mortality rate is 50% to 80%.

Dignani MC, Anaissie E: Human fusariosis, Clin Microbiol Infect 10:67–75, 2004.