common biopsy finding, and may often be confused with malignant lymphoma. It may be separated into major morphologic patterns, each with its own differential diagnosis with certain types of lymphoma. Most cases of reactive follicular hyperplasia are easy to diagnose, but some cases may be confused with follicular lymphoma. There are seven distinct patterns of benign lymphadenopathy: Follicular hyperplasia: This is the most common type of reactive lymphadenopathy. Paracortical hyperplasia/Interfollicular hyperplasia: It is seen in viral infections, skin diseases, and nonspecific reactions. Sinus histiocytosis: It is seen in lymph nodes draining limbs, inflammatory lesions, and malignancies. Nodal extensive necrosis Nodal granulomatous inflammation Nodal extensive fibrosis (Connective tissue framework) Nodal deposition of interstitial substance These morphological patterns are never pure. Thus, reactive follicular hyperplasia can have a component of paracortical hyperplasia. However, this distinction is important for the differential diagnosis of the cause. Diagnosis In cervical lymphadenopathy (of the neck), it is routine to perform a throat examination including the use of a mirror and an endoscope. On ultrasound, B-mode imaging depicts lymph node morphology, whilst power Doppler can assess the vascular pattern. B-mode imaging features that can distinguish metastasis and lymphoma include size, shape, calcification, loss of hilar architecture, as well as intranodal necrosis. Soft tissue edema and nodal matting on B-mode imaging suggests tuberculous cervical lymphadenitis or previous radiation therapy. Serial monitoring of nodal size and vascularity are useful in assessing treatment response. Fine needle aspiration cytology (FNAC) has sensitivity and specificity percentages of 81% and 100%, respectively, in the histopathology of malignant cervical lymphadenopathy. PET-CT has proven to be helpful in identifying occult primary carcinomas of the head and neck, especially when applied as a guiding tool prior to panendoscopy, and may induce treatment related clinical decisions in up to 60% of cases. Classification Lymphadenopathy may be classified by: Size, where lymphadenopathy in adults is often defined as a short axis of one or more lymph nodes is greater than 10mm. By extent: Localized lymphadenopathy: due to localized spot of infection e.g., an infected spot on the scalp will cause lymph nodes in the neck on that same side to swell up Generalized lymphadenopathy: due to a systemic infection of the body e.g., influenza or secondary syphilis Persistent generalized lymphadenopathy (PGL): persisting for a long time, possibly without an apparent cause By localization: Hilar lymphadenopathy. Mediastinal lymphadenopathy Bilateral hilar lymphadenopathy Dermatopathic lymphadenopathy: lymphadenopathy associated with skin disease. By