Granulomatous lymphadenitis is a condition of chronic inflammation and histiocytes in the lymph nodes, states NCBI. Granulomatous lymphadenitis can be caused by reactive, infectious and malignant diseases.
Granuloma is formed when the immune system attempts to eliminate foreign bodies but is unable to do so. This results in a buildup of immune cells called granulocytes, forming the granuloma. Macrophages, or histiocytes, characterize a granuloma.
Granulomatous lymphadenitis is categorized in three different groups: caseating, noncaseating and suppurative. Caseating granuloma is chronic and characterized by necrosis, or cell death. Noncaseating is chronic, but it does not feature necrosis. Suppurative is characterized by acute onset coupled with necrosis. Identifying which type of granuloma is present is a useful diagnostic tool, as certain diseases present with particular types of granuloma. In diagnosis, the location of the granulomatous lymphadenitis is as important as its type. The appearance of granuloma on the face, bones, mouth cavity or skin can indicate diseases such as Wegener's granulomatosis or eosinophilic granuloma.
The type of disease causing the granulomatous lymphadenitis often can be tested for by fine-needle aspiration biopsy. The fluid obtained is sent to a laboratory for testing. Laboratory tests are often inconclusive, making the patient's history important. Granuloma is often caused by pathogens present in particular environments or by contact with certain animals. Mycoses, or fungal infections, are common causes of granuloma and can often be diagnosed by reviewing the places to which a patient has recently traveled.