Overlapping immunoglobulin G4-related disease and Rosai-Dorfman disease mimicking lung cancer

Abstract

To the Editor: We report the case of an elderly male referred with pulmonary opacities and extensive mediastinal lymphadenopathy suspicious for lung cancer. He was found to have Rosai–Dorfman disease in a lymph node and concomitant immunoglobulin (Ig)G4-related disease in the lung and kidney. An 83-yr-old male was referred with a pulmonary consolidation in the left lung with extensive lymphadenopathy without a pathological diagnosis. His past medical record showed gout for which he used colchicine only occasionally. Initially, he was referred to an internist with complaints of loss of appetite, weight loss and fatigue. His sense of taste was diminished and he had a dry mouth. No dyspnoea was present. He had a longstanding, non-productive cough. Until recently, he was remarkably fit for his age. He had quit smoking 45 yrs earlier after 30 pack-yrs. Physical examination was unremarkable except for a firm lymph node in the left supraclavicular region and minor pulmonary crackles basally on both sides. Spirometry results were normal. Initial laboratory analysis showed a normal complete blood count, and slightly elevated creatinine (168 μmol·L−1) and C-reactive protein (35 mg·L−1). A chest radiograph showed a hazy consolidation radiating from the left hilum to the periphery of the lung suggesting lung cancer. On computed tomography, diffuse opacification in the left lower lobe was seen with concomitant hilar, mediastinal (paratracheal and subcranial) and left supraclavicular lymphadenopathy. Fibreoptic bronchoscopy in our institution again revealed no endobronchial lesions. Pathological examination of lavage fluid from the left lower …