bubble_chart Overview

Pulmonary cryptococcosis is a subacute or chronic fungal disease caused by Cryptococcus neoformans infection. It primarily affects the lungs and central nervous system, but can also invade bones, skin, mucous membranes, and other organs.

bubble_chart Pathogenesis

The fungus typically enters the human body through the respiratory tract. The lungs are the primary site of infection. When a healthy individual inhales Cryptococcus, it can cause a pulmonary infection, which is often limited to the lungs and rarely presents symptoms, with a tendency to self-heal. However, in cases of excessive fatigue or in patients with immune deficiencies, such as those with advanced-stage malignant tumors, leukemia, or those undergoing long-term treatment with high-dose hormones, broad-spectrum antibiotics, and anticancer drugs, inhalation of the fungus can lead to the formation of lesions in the lungs. These lesions can then disseminate throughout the body via the bloodstream, often invading the central nervous system.

bubble_chart Pathological Changes

After infection, this bacterium only induces a grade I inflammatory response. Localized or extensive granuloma formation occurs in the lungs, with necrosis and cavitation being rare, and calcification and hilar lymph node enlargement being extremely uncommon. Small nodules may also form under the pleura. Cryptococcus can cause lesions in the gray matter of the brain on coronal sections, often leading to meningoencephalitis.

bubble_chart Clinical Manifestations

Pulmonary cryptococcosis can exist alone or occur simultaneously with cryptococcosis in other parts of the body. About one-third of cases are asymptomatic and are often discovered during chest X-ray examinations, sometimes misdiagnosed as lung cancer. Most patients may experience grade I cough, expectoration of a small amount of mucoid or bloody sputum, chest pain, low-grade fever, lack of strength, and weight loss. A few cases present as acute pneumonia, occasionally with signs of chest pain or lung excess changes and pleural effusion. When complicated by meningoencephalitis, the symptoms are pronounced and severe. There is often moderate fever, occasionally reaching a high of 40°C, accompanied by symptoms and signs of meningoencephalitis.

X-ray findings: Lesions are more commonly seen in the bilateral middle and lower lungs, but can also be unilateral or confined to one lobe. They may appear as isolated large spherical foci or several nodular lesions with no significant surrounding reaction, resembling tumors; or as diffuse foxtail millet-like granular shadows; or as patchy infiltrative shadows. About 10% of patients develop cavities.

bubble_chart Diagnosis

Sputum, pleural fluid, and cerebrospinal fluid can be diagnosed by ink smear or culture when Cryptococcus is detected. A positive complement fixation reaction also aids in diagnosis.

bubble_chart Treatment Measures

This disease often occurs when immune function is reduced, so various inducing factors should be eliminated. Early localized pulmonary granulomas or cavities can be treated with antifungal drugs, and surgical resection may be performed if necessary.