Giant cell pneumonia with DiGeorge syndrome
Clinical History
A 7 month-old male was admitted for severe pneumonia with respiratory compromise. Laboratory studies demonstrated leukocytosis and profound hypocalcemia. An inherited immunodeficiency syndrome was suspected. A CT scan of the chest revealed bilateral lobar pneumonia, and no thymus was seen. Dual-probe fluoresence in-situ hybridization for deletions of 10p13p14 and 22q11.2 was performed on the peripheral blood, revealing hemizygosity for 22q11.2 deletion. Flow cytometry on the peripheral blood revealed markedly decreased number of circulating CD45RA- and CD62L-positive naïve T-cells. Sputum was obtained via nasopharyngeal aspiration. Bacterial and fungal cultures were negative, but immunofluoresence for respiratory syncitial virus (RSV) was positive. The patient required mechanical ventilation shortly after admission. Despite aggressive antibacterial, antifungal and antiviral treatment, his respiratory function rapidly declined, and he died a few days after presentation.
Pathological Findings
At autopsy, no thymus tissue was present in the mediastinum. The great vessels were abnormal, with a vascular ring (right aortic arch with left ligamentum arteriosum ) encircling the trachea and esophagus. The lungs were extremely boggy and heavy with severe diffuse bilateral consolidation. There were no facial abnormalities.
