Clinical history: 56 year old man just returned from a golf vacation in Arizona. Now has shortness of breath and fever.
What is the diagnosis?
Coccidioides immitis, a saprophyte, is usually found in the soil of the Southwest USA. It is not endemic to Canada and the patient usually has a travel history to the Southwestern USA. Coccidiodomycosis affects both immunocompromised and immunocompetent people and present with an acute febrile illness or may be asymptomatic. In the immunocompromised, there may be disseminated infection.
Histologically and cytologically, the organisms appear as spherules measuring 60-80 nm in diameter and containing multiple endospores. This may have the appearance of "crushed pingpong balls". Single endospores may also be seen. The background is usually granular eosinophilic debris with little inflammation. Rupture of the endospores releases the organisms and propagates the infection. The organisms are positive with silver stains and PAS. Bronchial or bronchiolar-alveolar washes rarely detect the organism; FNA is much more successful.
Radiologically, a nodule may be seen that represents the non-caseating granuloma. The granuloma may undergo cavitation.