A Correlative Cytological and Histopathological Study on Superficial Lymphadenopathy.

The Lymph Node Is One Of The Major Anatomic Components Of The Immune System. Lymph Nodes Are The Most Widely Distributed And Easily Accessible Component Of Lymphoid Tissue And Hence They Are Frequently Examined For Diagnosis Of Lymphoreticular Disorders. Diagnosis Of Lymphadenopathy Depends Mainly On Excision Of A Gland And Histopathological Examination. For This, General Anaesthesia And Hospitalisation Are Required. Fine Needle Aspiration Cytology, On The Other Hand, Is Free From These Disadvantages And Can Safely Be Used As An Alternative Or Complementary Investigative Technique. Anatomy: Lymph Nodes Are Organized Collections Of Lymphoreticular Tissue In The Form Of Pink Gray, Kidney Shaped, Encapsulated Organs. They Are Located At Anatomically Constant Points Along The Course Of Lymphatic Vessels. The Common Sites Of Distribution For Clinical Consideration Are The Cervical, Axillary, Supraclavicular And Inguinal Regions. Histology: The Lymph Node Consists Of Lymphocyte Aggregations, Intermeshed With Lymphatic Sinuses Supported By Reticular Fibre Framework And Surrounded By Connective Tissue Capsule. The Lymph Node Has Cortex, Para Cortex, And Medulla. The Cortex Is Situated Beneath The Capsule And Contains Large Number Of Follicles. The Medulla Close To The Hilum Is Rich In Lymph Sinuses, Arteries, And Veins But Contains Only A Minor Lymphocytic Component. Both Cortex And Medulla Represent ‘B’zones. The Cortex Contains Primary And Secondary Follicles, Which Are Characterized By The Presence Of Central Pale Area Of Germinal Centers. The Cells Present In These Formations Are Blymphocytes Known As Follicular Center Cells (Centroblasts, Centrocytes Or Small And Large Cleaved And Noncleaved Cells), Macrophages, And Follicular Dentritic Cells. A Mantle Of Dark Staining Small B-Lymphocytes Surrounds The Germinal Centre. The Para Cortex Is The Zone Situated Between The Cortex And Medulla Which Contains The Mobile Pool Of T Lymphocytes50 Development: In Human Embryo, The Lymph Sacs From Which The Lymph Vessels Are Derived Are Six In Number. 2 Paired (Jugular And The Posterior Lymph Sacs) And Two Unpaired (The Retroperitoneal And Cysterna Chyli). From The Lymph Sacs, The Lymph Vessels Bud Out Along Lines Corresponding More Or Less Closely With The Course Of Embryonic Blood Vessels, Most Commonly Veins. All The Lymph Sacs Except The Cysterna Chyli Are At A Later Stage Divided By A Number Of Slender Connective Tissue Bridges; Subsequently They Are Invaded By Lymphocytes And Transformed Into Groups Of Lymph Nodes. Fine Needle Aspiration Cytology Of Lymph Node: A Normal Lymph Node Is Rarely Palpable. Cytological Characteristics Of Cells From A Normal Lymph Node Are Essentially Based On The Morphology Of Individual Cells As Observed In The Aspirate From A Reactive Lymph Node. The Lymphocytes Constitute 87% To 99%, Plasma Cells 0% To 5% And Remainder Cells (Histiocytes, Mast Cells, Eosinophils And Neutrophils) 1% To3%