Figure 4a: PET/CT horizontal view with evidence of FDG avidity in all lobes, with nodules as the dominant morph. Coronal view, showing the extensive interstitial process as well as the diffuse lymphadenopathy. Figure 4B: Bottom picture - skin biopsy demonstrates mycotic branched septate fibres and oval spores of variable size in the epidermis and the inflammatory infiltrate in the dermis (PAS and Grocott’s method)
4th challenge point: The PET-CT scan showed an extensive interstitial lung process. Usually, corticosteroids would be administered to prevent permanent changes, however, with the suspicion of fungal infection, the immunosuppressive treatment might be harmful.
4th learner reflection : Which disease could explain these findings? Which test/consult would you order to confirm your suspicion? Additional information in the 4thpodcast.
4th case progression: An immunological investigation was requested, including immunoglobulin IgG, IgG subclasses, IgA, IgM and lymphocyte differential which were, however, not suggestive of any major cellular or humoral immunodeficiency. Additionally, the granulocytes’ ability to produce reactive oxygen species was tested with the oxidative burst test, or dihydrorhodamine test was found to be markedly disturbed. This was a specific hallmark of primary immunodeficiency called chronic granulomatous disease (CGD). CGD patients are susceptible to fungal, bacterial and viral infections. At the same time, the results of beta-D-glucan test from BAL showed borderline levels (96 ug/mL, confirmatory result greater than 100 ug/mL) while an extensive mold-derived antigen specific IgG panel returned strongly positive for numerous types of molds. Therefore, treatment with antifungal voriconazole was initiated (20 mg/kg/day), as well as sulfamethoxazole - trimethoprim prophylaxis, which is a standard of care for CGD patients. Genetic testing was requested to confirm the CGD.