Q: In general, which are the most common pulmonary fungal infections to affect immunocompetent individuals, and which one affects immunocompromised patients?
show answer
A: In general, histoplasmosis, coccidioidomycosis, and paracoccidioidomycosis affect immunocompetent individuals; whereas aspergillosis, candidiasis, cryptococcosis, mucormycosis, and pneumocystosis affect immunocompromised ones.
Q: Can cryptococcal infection occur in immunocompetent individuals?
show answer
A: Cryptococcal infection usually occurs in immunocompromised patients. However, this infection, on rare occasions, can also affect immunocompetent individuals.
Q: Which fungi cause pulmonary cryptococcosis?
show answer
A: There are two varieties of Cryptococcus neoformans, which can cause pulmonary cryptococcosis: C. neoformans var gatti and var neoformans, which is more prevalent. Var neoformans occurs more commonly in immunocompromised hosts, including those with HIV infection, and var gatti occurs mainly in immunocompetent hosts.
Q: What are some characteristics of the fungi of the genus Cryptococcus?
show answer
A: Cryptococcus neoformans is a thin-walled, nonmycelial, monomorphic, budding encapsulated yeastlike fungus that has a global distribution, and is easily isolated from soil contaminated with feces of pigeon and decaying wood. Although infection usually occurs through the inhalation of cryptococcal spores, the lungs are the second most commonly affected organ after the meninges. It is not uncommon for patients to present with concomitant cryptococcal meningitis and pulmonary cryptococcal infection, particularly in patients with impaired T cell-mediated immunity. Pulmonary cryptococcosis in the immunocompetent host is rare and may be asymptomatic. The disease may also affect bones and skin, depending on the host's immune status.
Q: Which are the symptoms of pulmonary cryptococcosis?
show answer
A: The patients with pulmonary cryptococcosis usually present unspecific symptoms, which are those of upper respiratory infection, such as fever, cough, dyspnea, night sweats, purulent sputum, hemoptysis, chest pain, malaise, and weight loss. Immunocompetent patients with pulmonary cryptococcosis may be asymptomatic, and commonly it is found as an accidental finding on an X-ray.
Q: What characterizes the radiological appearance of pulmonary cryptococcosis?
show answer
A: Radiographic manifestations of pulmonary cryptococcosis are diverse and depend on immune status. The findings may include single or multiple scattered nodules and clustered nodules or masses, focal areas of segmental or lobar consolidation, and a reticulonodular pattern of opacities. The nodules and masses have a predominantly peripheral distribution. Cavitation of nodules or consolidation may occur. Other findings are miliary disease, pleural effusion, empyema, pneumothorax, lymphadenopathy, and mass invading the chest wall, which is more common in immunocompromised patients.
Q: Which are the most common CT features of pulmonary cryptococcosis in immunocompetent patients?
show answer
A: The most frequent abnormalities on chest CT scans in immunocompetent patients with pulmonary cryptococcosis are solitary nodule, and multiple clustered nodular or multiple scattered nodular patterns. The multiple nodules are the most commonly bilateral and mainly located close to the pleura. Other common findings are mass-like and airspace consolidation. Mediastinal, hilar, and axillary lymph nodes enlargement, as well as pleural effusions, are rare in immunocompetent patients. Lung lesions may persist for a long time, with divergence from the clinical response.
Q: What is the criterion for the diagnosis of pulmonary cryptococcosis?
show answer
A: The criterion to confirm the diagnosis of pulmonary cryptococcosis is the histopathologic presence of the organism by direct tissue examination at lung/pleural biopsy or at surgical tissue resection or transbronchial biopsy; a positive culture of a respiratory specimen, and by a positive serum cryptococcal antigen test associated with clinical or radiographic evidence of active pulmonary infection.
Q: What is the treatment for cryptococcus infection?
show answer
A: The treatment of Cryptococcus infection is usually with fluconazole for patients with mild to moderate symptoms. Amphotericin B and flucytosine associated with fluconazole is an option for severe disease. Surgical resection of lung masses affected with cryptococcosis can serve as an alternative in some patients.
Q: What is the differential diagnosis of pulmonary cryptococcosis?
show answer
A: The clinical presentation of isolated pulmonary cryptococcosis is unspecific, and the radiological pattern is non-pathognomonic, so it is essential to clarify the differential diagnosis with pulmonary tuberculosis, actinomycosis, semi-invasive aspergillosis. Other pulmonary fungal infections, parasitic infestations, primary lung neoplasia, or metastatic lesion also participate in the differential diagnosis.
Unable to process the form. Check for errors and try again.