Normal Histology: Lymph nodes (LN) are small, round or reniform organs located throughout the body along the lymphatic vessels. LN are more numerous in some districts and drain specific organs. Quiescent LN do not exceed 1 cm in diameter and are undetectable at a physical examination; any possible stimulus may cause their enlargement, making them clinically evident. If removed, LN are normally white-pinkish and homogenous. Any change in shape, consistency or colour of the cut surface, or a distinct nodular, haemorrhagic or ne-crotic change is suspicious for various pathological processes. In the quiescent state, LN show variable degrees of fatty metaplasia, especially those located in the axillary, inguinal or mesenteric regions. LN are surrounded by a fibrous capsule and are divided by septa. Beneath the capsule there is a subcapsular sinus connected to the cortical and medullary sinuses. The main role of LN is to process and present antigens that reach the cortical via the afferent lymphatic vessels to the LN immunocompetent cells.
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