Study of Cytomorphology of Tubercular and Granulamatous Lymph Node Swellings

Aspiration of lymph nodes was reported early in 1904 by Grieg and Gray for the diagnosis of Trypanosomiasis. In 1921, Guthrie described the application of FNAC in the diagnosis of lymph node lesions. Serves as an excellent clue to the underlying disease, the cytological features frequently correlate well with histologic appearance of the same lesion. Identification of granulomatous lesions are now considered as a valuable diagnostic aid and is gaining popularity. Tuberculosis and leprosy are the mycobacterial infections that may affect lymph nodes. The granulomatous inflammation of tuberculous lymphadenitis is typically associated with necrotic material, although sometimes the epithelioid granulomas are without necrosis, particularly in the earlier stages of the infection. The term caseous necrosis is based on the gross appearance of the necrotic material, which looks cheesy. At times liquefied necrotic material with marked polymorphonuclear infiltration gives rise to suppurative lymphadenitis. Sometimes the aspirates may just contain the necrotic material without evidence of epithelioid granuloma. The number of lymphoid cells and giant cells is also variable.