When Is 'Sarcoidosis' Not Sarcoidosis?

Stephen Paget, MD


January 13, 2016

Patient Profile

A 46-year-old woman presented to her primary care physician with a cough, and a chest x-ray showed hilar adenopathy. Mediastinoscopy was performed, and lymph node pathology revealed noncaseating granuloma. A diagnosis of sarcoidosis was made; but, because the patient was asymptomatic and had no significant organ dysfunction, no medications were recommended. Four months later, she developed the onset of left groin pain that radiated to the thigh and buttocks, and an MRI demonstrated a mass pressing on her left sciatic nerve. A lymph node and bone marrow biopsy showed non-Hodgkin lymphoma, and she was treated with systemic and intrathecal chemotherapy with full disease control. Six months later, when first seen by me for evaluation of her illness and in order to differentiate between sarcoidosis and non-Hodgkin lymphoma, she was asymptomatic save for chemotherapy-related neuropathy and mild finger discomfort. She denied fatigue, fever, night sweats, or weight loss.


So, the question here is whether she had two different diseases or whether the initial diagnosis of sarcoidosis was incorrect, and the noncaseating granuloma was a "red herring" and an early pathologic manifestation of her non-Hodgkin lymphoma. This brings up the issue of when noncaseating granuloma is truly a reflection of sarcoidosis and needs to be treated as such. When I see a noncaseating granuloma, I initially run away from the diagnosis of sarcoidosis as fast as possible in order to be sure that it truly reflects sarcoidosis and not one of the "look-a-likes." There are so many disorders that can present with noncaseating granuloma, including tuberculosis, leprosy, schistosomiasis, histoplasmosis, cryptococcosis, cat-scratch disease, Crohn disease, Listeria monocytogenes, Pneumocystis pneumonia, aspiration pneumonia, rheumatoid arthritis, systemic lupus erythematosus, granuloma annulare, foreign-body granuloma, and granulomas associated with vasculitis such as granulomatous polyangiitis/Wegener granulomatosis.

Granuloma (plural granulomas or granulomata) is an inflammation found in many diseases. It is a collection of immune cells known as histiocytes. Granulomas form when the immune system attempts to wall off substances it perceives as foreign but is unable to eliminate. Such substances include infectious organisms including bacteria and fungi as well as other materials such as keratin and suture fragments. The adjective granulomatous means characterized by granulomas. In pathology, a granuloma is an organized collection of macrophages. In medical practice, the most accurate use of the term "granuloma" requires a pathologist to examine surgically removed and specially colored (stained) tissue under a microscope.


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