Presentation of Sporothrix schenkii in pulmonary cytology specimens

Macrophages containing small ovoid intracytoplasmic yeast cells, surrounded by a slight "halo," were observed in Papanicolaou-stained smears of sputum submitted for cytologic examination from two patients with culture-confirmed pulmonary sporotrichosis. The cytologic findings are presented and discussed in relation to other pulmonary fungal infections and the appropriate stains to be used for their cytologic detection. The clinical symptoms of pulmonary sporotrichosis are nonspecific and may mimic those of tuberculosis or other diseases; the causative organism, Sporothrix schenkii, may remain undetected by routine microbiologic procedures unless there is cause to suspect the diagnosis. Sporotrichosis should be considered in the differential diagnosis when small ovoid intracellular yeast cells (2 microns to 4 microns in length) with an apparent "halo" are observed within macrophages in pulmonary cytology specimens; the recognition of these findings may aid in the diagnosis of this relatively rare disease.