Castlemans disease is a rare but potentially serious diagnosis and, therefore, this paper aims to enhance the medical community's knowledge of this diverse disease. This is a non-malignant angiofollicular nodular hyperplasia. There are three types according to the histological picture - hyalinvascular, plasmocellular and plasmablastic, and two types according to the clinical picture - unicentric and multicentric. The symptoms are rather heterogeneous, from an asymptomatic mass seen in the unicentric form, to life-threatening systemic inflammatory state with systemic symptoms in the multicentric form. Pathophysiological mechanism involves hypersecretion of IL-6 cytokin, although the process trigger is known only in a small proportion of cases. This is HHV-8 infection that, however, is not found in every patient with Castlemans disease. Aetiology in HHV-8 negative patients is unclear. The disease is associated with a range of autoimmune conditions and some haematological malignancies. Surgical resection, some-times followed with radiotherapy, is the gold standard in the treatment of the unicentric form. Anti-IL-6 monoclonal antibodies are the optimal therapy of the multicentric form, although other modalities, including corticosteroids, chemotherapy (CHOP, CVAD), immunomodulators and rituximab, given in monotherapy or in combination, are more accessible in real practice.