Sarcoidosis of the Lymph Nodes

Abstract

Sarcoidosis is one member of a large family of granulomatous disorders in which the common denominator is the histology of epithelioid cell granulomas. Like many other members of this loose-knit family, its etiology is unknown. It is a multisystem disorder that most commonly affects young adults presenting with intrathoracic, skin, and eye lesions. The diagnosis is most secure when clinicoradiographic findings are supported by histologic evidence of widespread noncaseating epithelioid cell granulomas in more than one system or by a positive Kveim-Siltzbach skin test. There is evidence of depression of delayed-type hypersensitivity with impairment of thymus-mediated suppressor T cells in the peripheral blood but with evidence of increased numbers and activity of helper T cells in the lungs and in bronchoalveolar fluid. These helper T cells activate B cells to produce raised serum immunoglobulins, raised lambda and kappa light chains, and increased titers of serum antibodies against many antigens. Other common features are circulating immune complexes also hypercalciuria with or without hypercalcemia.