Sarcoidosis

Sarcoidosis is a disease of unknown etiology believed by some to be a hyperimmune form of tuberculosis. Granulomatous lesions resembling tubercles without casea­tion develop in the regional and medi­astinal lymph nodes, in the spleen and in the bones and skin. The disease as a rule pursues a slow, benign course, with spon­taneous healing. More rarely a fatal course is observed with involvement of the lungs, nervous system and the heart. Lymphadenopathy and splenomegaly are usually present. The osseous lesions produce foci of bone resorption. When the uveal tract of the eye and the parotid glands are in­volved the condition is known as Heerfordt's syndrome. Involutional changes in the granulomatous nodules may result in the deposition of amyloid. A significant number of patients have a falsely positive Wassermann reaction and an unexplained increase in plasma globulins.

Brucellosis

Brucellosis (undulant fever) affects primarily the reticuloendothelial system, the joints and at times the reproductive organs, heart, vessels, lungs, meninges and kidneys. Three organisms, B. melitensis, B. abortus, and B. suis may produce the disease. The reservoir of infection is in goats, cattle and pigs. Infection occurs through contaminated milk or through meat handling. The organ­isms lodge in the lymph nodes and then in the blood stream. Diagnosis is confirmed by agglutination of Brucella organisms by the patient's serum. In the common nonfatal form there is a low-grade undulating fever. loss of weight, cough or gastro-intestinal symptoms with enlargement of the lymph nodes and spleen. These symptoms may persist intermittently for years. A maculo-papular skin eruption and arthritis may occur. The characteristic lesion is granulomatous with an infiltrate of epithelioid cells, macrophages and giant cells resem­bling the Reed-Sternberg cell of Hodgkin's disease. In rare fatal cases with septicemia there is necrosis of lymphoid tissues and widespread thrombophlebitis. Infected em­boli may produce mycotic aneurysms.