A 49-year-old man with superficial lymphadenopathy presented with symptoms of low-grade fever, general fatigue and weight loss. On examination, multiple superficial lymphadenopathies and brown macules were observed on the trunk. Laboratory studies revealed an elevation of serum C reactive protein and interleukin 6 (IL-6) in addition to polyclonal hyperimmunoglobulinaemia. High-resolution CT of the chest showed bilateral multiple nodules and patchy ground-glass opacities with interstitial thickening. Biopsy of the cervical lymph node and skin biopsy showed numerous perivascular plasma cells, which were characteristic of the plasma cell type of Castleman's disease. Surgical lung biopsy showed hyalinising granuloma, which are hyalinous nodular lesions surrounded by lymphoid cells. He was diagnosed with multicentric Castleman's disease complicated by pulmonary hyalinising granulomas; his symptoms improved by treatment with tocilizumab, which is a humanised antihuman IL-6 receptor monoclonal antibody and corticosteroid. This is the first report of a comorbid case successfully treated with tocilizumab and corticosteroid.