RadioGraphics, Vol 11, 365-381, Copyright © 1991 by Radiological Society of North America
Imaging of pediatric mediastinal histoplasmosis
SG Kirchner, M Hernanz-Schulman, SM Stein, PF Wright and RM Heller
Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232-2675.
Histoplasmosis can present a diagnostic dilemma if unusually large masses
of lymph nodes, invasive mediastinal fibrosis, or pericarditis result from
the infection. These rare, late sequelae are often first suspected from
findings on chest radiographs obtained for unrelated reasons. Organisms are
not always evident at histologic analysis at this stage. Mediastinal
granulomas consist of lobulated masses of enlarged lymph nodes with central
caseation, a peripheral thin capsule, and, occasionally, calcification. The
mass does not invade or compromise adjacent anatomic structures.
Mediastinal fibrosis invades and can seriously compromise the function of
the tracheobronchial tree, superior vena cava, pulmonary arteries and
veins, and esophagus; its symptoms mimic those of many other disorders.
Pericarditis is commonly accompanied by pericardial effusion, pneumonia,
and adenopathy. Although the radiologic findings of these conditions are
nonspecific, they can be used with the clinical findings to suggest a
diagnosis. Complications of histoplasmosis should be included in the
differential diagnosis for patients residing in areas endemic to
Histoplasma capsulatum.
