Chronic Granulomatous Disease (CGD) Mimicking Neoplasms: A Suspected Mediastinal Teratoma Unmasking as Thymic Granulomas Due to X-linked CGD, and 2 Related Cases

Abstract

Patients with chronic granulomatous disease (CGD) suffer from severe bacterial and fungal infections and deregulated inflammation, which are often associated with granuloma formation. We describe a 2-year-old boy who was seemingly healthy at the age of 1 year when a conventional chest radiograph was taken to exclude pulmonary aspiration of a piece of apple. Incidentally, a space-occupying mediastinal mass was revealed that was further evaluated by magnetic resonance imaging. Varying solid and also cystic, septated parts of the mass could be discerned and it was considered to be a teratoma. Removal of the mass by surgery was arduous because of adhesiveness to surrounding areas and led to severe complications. Unexpectedly, histopathologic examination revealed massive acute granulomatous inflammation with liquefied thymic cysts. X-linked CGD was subsequently diagnosed by a dihydrorhodamine 123 assay and sequencing of the CYBB gene (hotspot mutation c.742-743insA). This is the third example that we are aware of, where CGD granulomas were mistaken for neoplasms. The other 2 patients were initially believed to have tumors of the stomach and the urinary bladder, respectively. All patients initially received inadequate treatment. We discuss possible strategies to avoid such tragic confusions.

Thymitis in chronic granulomatous disease

“…Invasive examinations (biopsy and resection of the lesion) were not performed before additional antibiotic treatment, due to the high suspicion of spread of pathogens to the thymic region. Interestingly, another group reported a CGD patient with similar lesions in the thymus on chest magnetic resonance imaging (MRI): pathology of multiple thymic lesions indicated infiltration of inflammatory cells, granuloma formation, and cysts …”

“…(a, c) Thymic lesions are shown on contrast computed tomography at (a) the time of diagnosis of multiple thymic lesions and (c) at 12 weeks of treatment. (b) Thymic lesions on T1‐weighted contrast‐enhanced magnetic resonance imaging at 6 weeks of treatment; low‐signal‐intensity nodules are seen, similar to a previous report . (d) During the clinical course, the diameter of the thymic lesions on chest ultrasonography reduced during treatment with antibiotics and antifungal agents.…”

“…In patients without immunodeficiency diseases, mediastinal masses can be associated with neoplastic disease, including malignant lymphoma, esophageal diverticula, cysts, and goiter. Indeed, a mediastinal mass was extracted, as stated in a previous report, and CGD was diagnosed after the surgical intervention. In the present case, it was unclear how a pathogen could invade the thymus, given that blood cultures were negative.…”

Chronic Granulomatous Disease

“…Genitourinary complications are also highly steroid responsive. It is important to keep in mind that inflammatory masses in CGD can mimic tumors and should be considered (48).…”