Zygomycosis (mucormycosis) is a rare but highly invasive infection caused by fungi belonging to the order Mucorales, which includes the genera Rhizopus, Mucor, Rhizomucor, Absidia, Apophysomyces, Saksenaea, Cunninghamella, Cokeromyces and Syncephalastrum. This type of infection is usually associated with hematologic diseases, diabetic ketoacidosis and organ transplantation. The most common form of presentation is rhinocerebral mucormycosis, with or without pulmonary involvement. Pulmonary zygomycosis is more common in patients with profound, prolonged neutropenia and can present as segmental or lobar infiltrates, isolated nodules, cavitary lesions, hemorrhage or infarction. The clinical and radiological manifestations are often indistinguishable from those associated with invasive aspergillosis. This article describes the general characteristics of pulmonary zygomycosis, emphasizing laboratory diagnosis, and illustrates the morphology of some lesions.

Keywords: Zygomycosis; Diagnostic techniques and procedures; Mucormycosis.

Objective: To report the cases of 6 patients with fungus ball caused by Aspergillus fumigatus (aspergilloma) in the pleural cavity. Methods: Between 1980 and 2009, 391 patients were diagnosed with aspergilloma at the Santa Casa Hospital Complex in Porto Alegre, Brazil. The diagnosis of aspergilloma in the pleural cavity was made through imaging tests revealing effusion and pleural thickening with air-fluid level; direct mycological examination revealing septate hyphae, consistent with Aspergillus sp.; and positive culture for A. fumigatus in the surgical specimen from the pleural cavity. Results: Of the 391 patients studied, 6 (2%) met the established diagnostic criteria. The mean age of those 6 patients was 48 years (range, 29-66 years), and 5 (83%) were male. The most common complaints were cough, expectoration, and hemoptysis. Four patients (67%) had a history of tuberculosis that had been clinically cured. All of the patients were submitted to surgical removal of the aspergilloma, followed by intrapleural instillation of amphotericin B, in 4; and 2 received systemic antifungal treatment p.o. There was clinical improvement in 5 patients, and 1 died after the surgery. Conclusions: In adult patients with a history of cavitary lung disease or pleural fistula, a careful investigation should be carried out and fungal infection, especially aspergilloma, should be taken into consideration. In such cases, laboratory testing represents the most efficient use of the resources available to elucidate the diagnosis.

Keywords: Aspergillus fumigatus; Tuberculosis; Empyema, pleural; Pleural effusion.

Objective: To describe the main clinical and radiological characteristics of patients with histoplasmosis mimicking lung cancer. Methods: This was a retrospective descriptive study based on the analysis of the medical records of the 294 patients diagnosed with histoplasmosis between 1977 and 2011 at the Mycology Laboratory of the Santa Casa Sisters of Mercy Hospital of Porto Alegre in the city of Porto Alegre, Brazil. The diagnosis of histoplasmosis was established by culture, histopathological examination, or immunodiffusion testing (identification of M or H precipitation bands). After identifying the patients with macroscopic lesions, as well as radiological and CT findings consistent with malignancy, we divided the patients into two groups: those with a history of cancer and presenting with lesions mimicking metastases (HC group); and those with no such history but also presenting with lesions mimicking metastases (NHC group). Results: Of the 294 patients diagnosed with histoplasmosis, 15 had presented with lesions mimicking primary neoplasia or metastases (9 and 6 in the HC and NHC groups, respectively). The age of the patients ranged from 13 to 67 years (median, 44 years). Of the 15 patients, 14 (93%) presented with pulmonary lesions at the time of hospitalization. Conclusions: The clinical and radiological syndrome of neoplastic disease is not confined to malignancy, and granulomatous infectious diseases must therefore be considered in the differential diagnosis.

Keywords: Histoplasmosis; Multiple pulmonary nodules; Solitary pulmonary nodule.