The University of Louisville Journal of Respiratory Infections


In this case report, we describe a case of progressive acute pulmonary blastomycosis in a healthy adult living in Kentucky, initially presenting with flu like illness with a left sided consolidation, who did not respond to antibiotic therapy. Patient’s clinical condition deteriorated with development of necrotizing bronchopneumonia, mediastinal lymphadenopathy, tree-in-bud reticulonodularity and pleural effusion. A diagnosis of progressive pulmonary blastomycosis was established by radiological findings as well as transbronchial needle aspiration cytology and bronchoalveolar lavage culture demonstrating Blastomyces dermatitidis. Patient showed significant clinical improvement with resolution of pulmonary lesions on antifungal treatment. Since symptoms of blastomycosis are often similar to the symptoms of flu or other lung infections, our case highlights the importance of maintaining a high index of suspicion and appropriate microbiologic and histologic evaluation especially in patients who live in or have traveled to areas endemic for blastomycosis and are not responding to antibiotic therapy. Early diagnosis coupled with prompt initiation of antifungal treatment may lead to favorable outcomes.


No financial support.



Figure 1 v2.png (140 kB)
Figure 1. Initial Chest X-ray (CXR) showing ovoid superior segment left lower lobe consolidation.

Figure 2 v2.png (451 kB)
Figure 2. Chest computed tomographic (CT) scan showing dense consolidation involving the majority of the left lower lobe and trace left pleural effusion.

Figure 3 v2.png (652 kB)
Figure 3. Chest X-ray (CXR) showing left lower lobe consolidation with cavitary changes consistent with necrotizing pneumonia.

Figure 4.png (438 kB)
Figure 4. Chest computed tomographic (CT) scan showing dense necrotizing bronchopneumonia seen throughout left lower lobe with left hilar, central mediastinal lymphadenopathy, and “tree-in-bud” reticulonodularity identified throughout the remainder of lungs with scattered areas of non-cavitary satellite nodularity.

Figure 5 v2.png (669 kB)
Figure 5. Chest X-ray (CXR) showing persistent diffuse bilateral pneumonia, left greater than right, with a moderate left-sided pleural effusion.

Figure 6.png (419 kB)
Figure 6. Chest computed tomographic (CT) scan showing worsening diffuse pneumonia with complete consolidation of the left lower lobe, new patchy consolidation in the left upper lobe/lingula and right lower lobe and new/enlarging nodules in the right lung. New small left pleural effusion with fluid in the fissure and layering over the apex.

Figure 7a.png (1791 kB)
Figure 7a. Hematoxylin-and-eosin-stained section of left lower lobe lung biopsy, low-power (Bottom) and high-power (Top) magnification, shows numerous lymphocytes, histiocytes, many multinucleated giant cells, forming ill-defined granulomas and presence of thick-walled single yeast forms of approximately 8–15 µm in size with eccentric broad-based budding overall morphology consistent with blastomycosis.

Figure 7b.jpg (300 kB)
Figure 7b. Gomori methenamine silver (GMS) (1000X magnification) stain shows a budding yeast of Blastomyces dermatitidis with the characteristic broad-based bud.

Figure 8a.png (965 kB)
Figure 8a. Phase-contrast microscopy: (1000X magnification): Shows the typical appearance of Blastomyces dermatitidis. Round to oval shape, thick, doubly refractile cell wall, and single broad-based bud.

Figure 8b.jpg (210 kB)
Figure 8b. Lacto-Phenol-Cotton-Blue Stain (LPCB) (1000X magnification): Shows the mold form of Blastomyces dermatitidis characterized by delicate, septate hyphae, unbranched conidiophores of rather short, yet varying length extending from the hyphae. Conidia are produced singly at the apex of the conidiophore or develop directly on the hyphae. Conidia are unicellular, round to pyriform (tear drop) in shape (~2 to 10 µm dia.). Conidia at the terminal end of the conidiophore resemble a “lollipop” in structure.

Figure 8c.jpg (112 kB)
Figure 8c. Bronchial and BAL culture using Sabouraud Dextrose Agar (SDA): Blastomyces dermatitidis takes 2 to 3 weeks to grow at 25 to 30 degrees C. Blastomyces dermatitidis appears as white to beige cottony, mold (mycelium) on Sabouraud dextrose agar.



To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.