대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Pulmonary histoplasmosis

Radiologic Findings

Fig 1-2. Chest CT shows an about 2.2-cm sized irregular solid nodule with fissural retraction in the superior segment of left lower lobe. The lesion was not seen on chest CT taken a year earlier.
Fig 3. F-18 FDG PET-CT shows intense FDG uptake of the nodule (SUVmax 6.5).

Brief Review

Pulmonary histoplasmosis is an infection caused by Histoplasma capsulatum, which is an organism endemic to El Salvador but can be found widely in other parts of North, Central, and South America, and to a lesser extent in Subsaharan Africa, the central Mediterranean, Southeast Asia, and Eastern Australia. Since it is not endemic in Korea, pulmonary histioplasmosis is usually not in the differential diagnosis in Korean hospitals.

Pulmonary histioplasmosis can show variable clinical and radiographic presentations depending on the state of infection and other host co-morbidities. The clinical manifestations of pulmonary histioplasmosis are various and nonspecific, ranging from asymptomatic to severe and fatal. CT findings are also varied and nonspecific. Most common CT findings are nodular opacities (solitary or multiple), consolidations, and ground-glass opacities. The use of PET-CT is of little use in differentiating pulmonary histioplasmosis from malignancy, because it can also show high levels of FDG uptake, similar to our patient.

References

1. Mango ALD, Gomes ACP, Hochhegger B, Zanetti G, Marchiori E. Computed tomography findings of pulmonary histoplasmosis: pictorial essay. Radiol Bras. 2023 May-Jun;56(3):162-167.
2. Kennedy, Cassie C. MD; Limper, Andrew H. MD. Redefining the Clinical Spectrum of Chronic Pulmonary Histoplasmosis: A Retrospective Case Series of 46 Patients. Medicine 86(4):p 252-258, July 2007.

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