A Case of Multicentric Castleman's Disease Presenting with Follicular Bronchiolitis
A 37-year-old human immunodeficienct virus-negative Korean woman was referred to our hospital for one year of cough with mucoid sputum. She had no hemoptysis, dyspnea, nor chest pain. She had lost 6 kg in the past 3 months. She was a nonsmoker and had no noteworthy specific family history. Physical examination on admission showed no abnormality. Laboratory data included a normochromic normocytic anemia with hemoglobin of 10.4 g/dL and elevated serum protein (11.5 g/dL) with hypoalbuminemia (2.8 g/dL). Serum protein electrophoresis showed polyclonal gammopathy and increased α2-globulin level (1.3 g/dL). The levels of erythrocyte sedimentation rate (ESR, 120 mm/hr) and serum C-reactive protein (CRP, 7.1 mg/dL) were elevated, but serum lactate dehydrogenase level was within the normal range. On lung function test, no ventilator impairment was noted, but diffusing capacity for carbon monoxide corrected for hemoglobin was reduced (15.8 mL/mm Hg/min [69% pred.]). Chest radiography showed thickened bronchovascular markings and diffuse bilateral reticulonodular opacities in both lungs (). Enhanced chest computed tomography (CT) scan demonstrated multiple mediastinal and hilar lymph node enlargement () and high-resolution CT scan showed the thickening of bronchovascular bundles, interlobular septal thickening, and poorly defined centrilobular nodules in both lungs ().\nBronchoalveolar lavage (BAL) fluid analysis demonstrated an increase in the total cell count (3.0×105/mL) with a normal distribution of differential cell count (98% alveolar macrophages, 1% lymphocyte, and 1% neutrophil). Flow cytometric analysis for BAL fluid disclosed a reduction of CD4+/CD8+ cell ratio (0.82). However, transbronchial lung biopsy did not give any useful diagnostic results, except for chronic inflammation. For a pathologic diagnosis, she underwent a video-assisted thoracoscopic surgery (VATS) for lung tissues and mediastinal lymph nodes. VATS biopsy revealed typical findings of plasma cell type CD in the mediastinal lymph node () and many hyperplastic lymphoid follicles with reactive germinal centers, located around the bronchioles in the lung tissue (). No remarkable lymphocytic and plasma cell infiltration were observed in the interstitium of alveolar walls.\nShe was diagnosed as having multicentric CD with a pulmonary involvement. She received a high dose prednisolone therapy (1 mg/kg/day), which was tapered over 6 months. At 6 months, a repeat CT scan demonstrated a slight reduction in size of mediastinal lymph nodes, but no significant improvement was observed in lung parenchymal lesions. Then, she underwent azathioprine combined with prednisolone, but did not experience any significant improvement on chest CT scan.