Summary This document provides a comprehensive overview of vascular pathology, covering venous disorders such as varicose veins and deep vein thrombosis, and ly
Summary This document provides a comprehensive overview of vascular pathology, covering venous disorders such as varicose veins and deep vein thrombosis, and lymphatic conditions including lymphangitis and lymphoedema. It thoroughly classifies and details various vascular tumors, from benign hemangiomas and lymphangiomas to intermediate-grade Kaposi Sarcoma and malignant angiosarcoma, highlighting their unique clinical features and associations. Furthermore, the notes address the pathology related to modern vascular interventions like endovascular stenting and different types of bypass grafts. Key Points - Varicose veins are abnormally dilated, tortuous superficial veins caused by increased intraluminal pressure and incompetent valves, rarely leading to embolism unlike deep vein thrombosis (DVT). - Lymphatic disorders encompass acute lymphangitis, often bacterial, and lymphoedema, which can be primary or secondary to lymphatic obstruction by tumors, surgery, or filariasis. - Vascular tumors range from common benign hemangiomas, which often regress spontaneously, to aggressive malignant angiosarcomas and HHV8-associated Kaposi Sarcoma, particularly in immunocompromised individuals. - Endovascular stenting effectively dilates arterial stenoses but carries risks of immediate thrombosis and long-term in-stent restenosis, with drug-eluting stents reducing restenosis but requiring prolonged anticoagulation. - Vascular replacement for coronary bypass utilizes saphenous vein grafts with limited long-term patency due to atherosclerosis and intimal hyperplasia, while internal mammary artery grafts offer superior patency for specific applications. Detailed Notes OUTLINE Section 1: Venous Disorders - Varicose Veins - Phlebothrombosis and Thrombophlebitis Section 2: Lymphatic Disorders - Lymphangitis - Lymphoedema Section 3: Vascular Tumours - Classification Overview - Vascular Ectasias (Nevus Flammeus, Spider Telangiectasia, Osler-Weber-Rendu) - Benign Tumours — Capillary Hemangioma · Cavernous Hemangioma · Pyogenic Granuloma · Lymphangioma · Glomus Tumour - Reactive Proliferations — Bacillary Angiomatosis - Intermediate-Grade — Kaposi Sarcoma - Malignant — Angiosarcoma Section 4: Pathology of Vascular Intervention - Endovascular Stenting and Restenosis - Vascular Replacement and Bypass Grafts SECTION 1: VENOUS DISORDERS Varicose Veins - Abnormally dilated, tortuous veins produced by prolonged increased intraluminal pressure with vessel dilation and incompetence of venous valves - Superficial veins of the upper and lower leg most commonly involved — venous pressures in these sites can be elevated up to 10 times normal by prolonged dependent posture - Affect up to 20% of men and one third of women Risk Factors: - Obesity — increases risk - Pregnancy — gravid uterus compresses inferior vena cava ↑ venous pressure; explains higher incidence in women - Familial predilection — reflects defective venous wall development Clinical Features: - Incompetence of venous valves → stasis, congestion, oedema, pain, thrombosis - Secondary tissue ischaemia from chronic venous congestion and poor vessel drainage: - Stasis dermatitis (also called "brawny induration") — brawny colour from haemolysis of extravasated red cells - Ulcerations — poor wound healing; superimposed infections common - Embolism from superficial varicose veins is very rare — in contrast to relatively frequent thromboembolism from deep vein thrombosis Two other important varicosity sites: - Oesophageal varices — from portal hypertension (covered in GI pathology notes) - Haemorrhoids — anal and perianal collaterals; from portal hypertension or straining Phlebothrombosis and Thrombophlebitis - Phlebothrombosis — thrombosis of veins with only minimal inflammatory response - Thrombophlebitis — venous thrombosis associated with prominent venous wall inflammation - Together these account for at least 90% of clinical venous disease Deep Vein Thrombosis (DVT): - Most often involves deep leg veins (popliteal, femoral, iliac) - Major risk: pulmonary embolism — thrombi may propagate to involve larger veins, dislodge, and embolise - Risk factors ( Virchow's triad ): stasis + hypercoagulability + endothelial injury - Clinical: leg pain, swelling, warmth — but up to 50% are clinically silent - Unlike superficial varicosities, deep vein thrombosis is a major source of pulmonary embolism Migratory Thrombophlebitis (Trousseau Syndrome): - Repeated thrombophlebitis in different venous sites - Associated with occult visceral malignancy (especially pancreatic, lung, GI carcinomas) - Mechanism: tumour-derived mucins and other procoagulants activate clotting SECTION 2: LYMPHATIC DISORDERS Lymphangitis - Acute inflammation from spread of bacterial infections into lymphatics - Most common agent: group A β-haemolytic Streptococcus - Morphology: affected lymphatics dilated and filled with exudate of neutrophils and monocytes; infiltrates can extend through vessel wall → cellulitis or focal abscesses - Clinical features: - Red, painful subcutaneous streaks (inflamed lymphatics tracking proximally) - Painful enlargement of draining lymph nodes (lymphadenitis) - If bacteria not contained within lymph nodes → escape into venous circulation → bacteraemia or sepsis Lymphoedema Primary Lymphoedema: - Isolated congenital defect (simple congenital lymphoedema) - Milroy disease (heredofamilial congenital lymphoedema) — lymphatic agenesis or hypoplasia Secondary (Obstructive) Lymphoedema — Causes: - Tumours obstructing lymphatic channels or regional lymph nodes - Surgical procedures severing lymphatic connections (e.g. axillary lymph node resection in radical mastectomy) - Post-radiation fibrosis - Filariasis — parasitic obstruction (most common worldwide cause of massive lymphoedema) - Post-inflammatory thrombosis and scarring Pathophysiology: - Blockage → increased hydrostatic pressure distal to obstruction → oedema - Chronic oedema → ECM deposition + fibrosis → brawny induration or peau d'orange appearance of overlying skin - Inadequate tissue perfusion → skin ulceration Rupture of dilated lymphatics: - Chylous ascites — abdomen - Chylothorax — thorax - Chylopericardium — pericardium SECTION 3: VASCULAR TUMOURS Classification Overview Category Examples --- --- Benign Hemangioma (capillary, cavernous), pyogenic granuloma, lymphangioma, glomus tumour, vascular ectasias Reactive/Borderline Bacillary angiomatosis, Kaposi sarcoma, hemangioendothelioma Malignant Angiosarcoma, hemangiopericytoma General Principles: - Vascular neoplasms arise from endothelium (hemangioma, lymphangioma, angiosarcoma) OR from cells supporting blood vessels (glomus tumour) - Benign tumours: obvious vascular channels filled with blood cells, lined by a monolayer of normal-appearing ECs - Malignant tumours: more solidly cellular, proliferative, exhibit cytologic atypia ; usually do not form well-organised vessels - Endothelial origin of malignant tumours confirmed by immunohistochemical staining for CD31 or von Willebrand factor Vascular Ectasias - Generic term for local dilation of existing vessels — NOT true neoplasms - Telangiectasia — permanent dilation of pre-existing small vessels (capillaries, venules, arterioles), usually in skin or mucous membranes Nevus Flammeus ("Birthmark"): - Most common form of vascular ectasia - Light pink to deep purple flat lesion on head or neck composed of dilated vessels - Most ultimately regress spontaneously - Port wine stain — type of nevus flammeus that tends to grow during childhood , thickening skin, and persists over time - Port wine stain in trigeminal nerve distribution → Sturge-Weber syndrome (encephalotrigeminal angiomatosis): - Facial port wine nevi - Ipsilateral venous angiomas in cortical leptomeninges - Intellectual disability, seizures, hemiplegia, skull radiopacities - Caused by somatic GNAQ missense mutation (Gα subunit) Spider Telangiectasias: - Nonneoplastic vascular malformations grossly resembling a spider - Radia