대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Pulmonary cryptococcosis

Radiologic Findings

Figure 1. Chest PA shows small nodular infiltration and cardiomegaly with pulmonary arterial dilatation.
Figures 2-6. Chest CT demonstrates diffuse ill-defined centrilobular nodules and ground-glass opacities in both lungs, with additional ill-defined peripheral nodules in the upper, right middle, and lower lobes. Marked dilatation of the main pulmonary artery with cardiomegaly is noted, consistent with pulmonary arterial hypertension.

Brief Review

Contrast-enhanced spine and brain MRI showed diffuse leptomeningeal thickening and enhancement, consistent with leptomeningitis.

Cryptococcosis is an opportunistic fungal infection caused by Cryptococcus neoformans or C. gattii, most commonly affecting immunocompromised patients, including those with systemic lupus erythematosus. The lung is the primary site of infection, and radiologic manifestations of pulmonary cryptococcosis are highly variable, ranging from solitary or multiple nodules to diffuse ground-glass opacities, often mimicking other infectious or inflammatory lung diseases.
In this case, chest CT demonstrated diffuse ill-defined centrilobular nodules with ground-glass opacities and additional ill-defined peripheral nodules without lymphadenopathy. In an immunocompromised patient presenting with fever, the initial differential diagnosis included opportunistic infections such as Pneumocystis jirovecii pneumonia or viral pneumonia, as well as autoimmune-related pneumonitis. However, the presence of peripheral nodules and the absence of typical imaging features of PJP or CMV pneumonia made these diagnoses less likely. Concurrently, the patient showed leptomeningeal enhancement on brain and spine MRI, and cerebrospinal fluid analysis was consistent with meningitis. Subsequent serum cryptococcal antigen testing was positive, and antifungal therapy with amphotericin B and fluconazole was initiated, supporting the diagnosis of pulmonary cryptococcosis with central nervous system involvement. This case highlights that pulmonary cryptococcosis should be considered in immunocompromised patients presenting with atypical pulmonary nodules and systemic or neurologic manifestations, even when imaging findings are nonspecific.

References

1. Song KD, Lee KS, Chung MP, Kwon OJ, Kim TS, Yi CA, Chung MJ. Pulmonary cryptococcosis: imaging findings in 23 non-AIDS patients. Korean J Radiol. 2010 Jul-Aug;11(4):407-16.
2. Xiong C, Lu J, Chen T, Xu R. Comparison of the clinical manifestations and chest CT findings of pulmonary cryptococcosis in immunocompetent and immunocompromised patients: a systematic review and meta-analysis. BMC Pulm Med. 2022 Nov 11;22(1):415.

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