[Interstitial pneumonia, pulmonary thrombotic microangiopathy, and hyperimmunoglobulinemia associated with Basedow's...

A 44-year-old man with a history of Basedow's disease complained of dry cough and lymphadenopathy. Polyclonal hypergammaglobulinemia (IgG level: 5,839 mg/dl) was present, and the patient's serum was positive for lupus anticoagulant. Chest radiography disclosed irregular thickening of bronchovascular bundles, centrilobular granular and branching opacities, and small cystic changes in both lung fields. Examination of a thoracoscopic biopsy specimen revealed fibrous thickening of the pleura, interlobular septum, and peribronchiolar/perivascular connective tissue, with mild round-cell infiltration. Lymphoid follicle formation and pulmonary thrombotic microangiopathy were also observed. Corticosteroid therapy was ineffective for hypergammaglobulinemia and diffuse opacities disclosed by chest computed tomographic scans. This case differed from multicentric Castleman's disease with respect to the pathological findings of a lymph nodes biopsy, and also was not consistent with any known collagen vascular disease, (e.g., Sjögren's syndrome). We suspect this case may be representative of a new form of collagen vascular disease.