Correspondence

Aspergillus Fungus Balls on the Mitral Valve

N Engl J Med 2001; 344:310-311January 25, 2001

Article

To the Editor:

The term “fungus ball” refers to a saprophytic colonization of a cavity by fungous hyphae without invasion of adjacent tissue.1 It usually occurs in the lung (typically in a parenchymal cavity or an ectatic bronchus), the paranasal sinuses, the nasal and auricular cavities, or the urinary tract.2 Aspergillus is most commonly involved in the formation of fungus balls, although these growths may occasionally be caused by candida, Pseudallescheria boydii, sporothrix, or penicillium or by bacteria (namely, nocardia).

We report a case of fungus balls within the heart cavities. A previously healthy 56-year-old woman was admitted with pneumonia and was treated with broad-spectrum antibiotics for about one month. Her condition improved until severe mitral regurgitation with pulmonary edema suddenly developed. Transthoracic echocardiography showed numerous nodular vegetations around the chordae tendineae, some of which appeared to have ruptured. The patient underwent emergency replacement of the mitral valve with a mechanical prosthesis.

Gross examination of the surgical specimen revealed large, spherical, smooth masses surrounding the chordae; the valvular leaflets appeared normal (Figure 1AFigure 1Aspergillus Fungus Balls from the Mitral Valve.). Microscopically, the nodules consisted of uniform, compact, parallel hyphae arranged concentrically around the chordae and showing degenerative changes or frank necrosis. There was no invasion of the chordal tissue, where only a mild inflammatory infiltrate composed of histiocytes and eosinophils was noted. Grocott silver staining showed septate, dichotomously branched hyphae measuring 2.5 to 3.5 μm in diameter — findings characteristic of aspergillus (Figure 1B). Intravenous amphotericin B therapy was started, but the patient died of congestive heart failure 10 days after surgery. An autopsy was not performed.

The pathogenesis of the infection in this patient is unclear. The organism must have reached the cardiac chambers through the bloodstream, and the point of entry was probably the lungs, which are constantly exposed to the aspergillus spores that are present virtually everywhere in the environment. Both the pneumonia and the use of broad-spectrum antibiotics presumably favored the development of this form of saprophytic aspergillosis of the heart.3 Rupture of some of the chordae tendineae may have been caused by mechanical impairment of the valve, rather than by pathologic changes in the valvular apparatus.

Franca Gori, M.D.
Gabriella Nesi, M.D.
Elena Pedemonte, M.D.
University of Florence, 50184 Florence, Italy

3 References

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   Fraser RS. Pulmonary aspergillosis: pathologic and pathogenetic features. Pathol Annu 1993;28:231-277
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   Mikkilineni RS, Flores D. Fungus ball. N Engl J Med 1995;332:91-91
   Full Text | Web of Science | Medline

3. 3

   Atkinson JB, Connor DH, Robinowitz M, McAllister HA, Virmani R. Cardiac fungal infections: review of autopsy findings in 60 patients. Hum Pathol 1984;15:935-942
   CrossRef | Web of Science | Medline

Citing Articles (1)

Citing Articles

1. 1

   Elizabeth Cerceo, Robert M. Kotloff, Denis Hadjiliadis, Vivek N. Ahya, Alberto Pochettino, Colin Gillespie, Jason D. Christie. (2009) Central Airways Obstruction Due to Aspergillus fumigatus After Lung Transplantation. The Journal of Heart and Lung Transplantation 28:5, 515-519
   CrossRef