Serdar Balcı

Pathology of Vessels Non-Atherosclerotic Vascular Diseases

Serdar BALCI, MD


Pathology of Vessels

Different vascular structures for different purposes

Robbins Basic Pathology

Layers of vessels


Small arteries (<2mm)

Arterioles (20-100 µm)

Connective tissue of organs

Media mostly composed of smooth muscle

Arterioles regulate blood flow resistance

Flow becomes steady rather than pulsatile


7-8µm, diameter of RBC

Lined by endothelial cells

Smooth muscle cell-like cells → pericytes

Rapid exchange of diffusible substances between blood and tissue

Diffusion of oxygen and nutrients is not efficient beyond 100 µm

Metabolically active tissues (heart) have the highest capillary density



Thin-walled, endothelium-lined channels

Excess fluid


Mononuclear cells

Tumors and infections

Robbins Basic Pathology


Endothelial activation

Bacterial products

Inflammatory cytokines

Hemodynamic stresses

Lipid products (atherosclerosis)

Advanced glycolysis products (diabetes)



Metabolic insults (hypoxia)

Activated endothelial cells

Endothelial dysfunction

Endothelium-dependent vasodilation

Hypercoagulable states

Increased oxygen free radical production

Initiate thrombosis

Promote atherosclerosis

Formation of the vascular lesions of hypertension and diabetes

Vascular Smooth Muscle Cells

Normal vascular repair



Upregulate ECM collagen, elastin, and proteoglycan

Form growth factors and cytokines

Mediate vasoconstriction or vasodilation

Robbins Basic Pathology



Berry aneurysms

Thin-walled arterial outpouchings in cerebral vessels

Branch points around the circle of Willis

Arterial media is congenitally attenuated

Spontaneously rupture

Fatal intracerebral hemorrhage

Arteriovenous fistulas

Fibromuscular dysplasia


Raynaud phenomenon

Primary Raynaud phenomenon

Secondary Raynaud phenomenon

Myocardial Vessel Vasospasm

Vasospasm of cardiac arterial or arteriolar beds (cardiac Raynaud) 20-30 minutes → myocardial infarction

Elevated levels of catechols increase heart rate and myocardial contractility → increase ischemia caused by the vasospasm

Sudden cardiac death (fatal arrhythmia)

Ischemic dilated cardiomyopathy


Varicose Veins of the Extremities

Abnormally dilated tortuous veins

Chronically increased intraluminal pressures

Weakened vessel wall support

Superficial veins of the upper and lower leg

20% of men and a third of women develop lower extremity varicose veins

Obesity, compression of the inferior vena cava during pregnancy

Familial tendency

Congestion in Portal Vein

Thrombophlebitis and Phlebothrombosis

Thrombosis and inflammation

Deep leg veins

Periprostatic venous plexus in males

Pelvic venous plexus in females

Large veins in the skull and the dural sinuses

Peritoneal infections

Hypercoagulability (polycythemia vera)

Deep venous thrombosis of the legs

Superior Vena Cava Syndromes

Neoplasms that compress or invade the superior vena cava

Bronchogenic carcinoma

Mediastinal lymphoma

Marked dilation of the veins of the head, neck, and arms


Pulmonary vessels compressed → Respiratory distress

Inferior vena cava syndrome

Neoplasms that compress or invade the inferior vena cava

Thrombus from the hepatic, renal, or lower extremity veins

Hepatocellular carcinoma and renal cell carcinoma grow within veins

Marked lower extremity edema

Distention of the superficial collateral veins of the lower abdomen



Acute inflammatory process by bacterial seeding

Red, painful subcutaneous streaks

Tender enlargement of draining lymph nodes (acute lymphadenitis)

Bacteremia or sepsis



Robbins Basic Pathology

Vascular Tumors

Vascular Ectasias

Capillary hemangiomas

Most common type


Subcutaneous tissues

Mucous membranes of the oral cavities and lips

Liver, spleen, and kidneys

Thin-walled capillaries with scant stroma

Robbins Basic Pathology

Robbins Basic Pathology

Juvenile hemangiomas Strawberry hemangiomas

Newborn skin

Common (1 in 200 births)

Can be multiple

Grow rapidly for a few months but then fade by the age of 1 to 3 years, with complete regression by age 7

Pyogenic granulomas

Capillary hemangiomas

Rapidly growing red pedunculated lesions on the skin, gingival, or oral mucosa

Resemble exuberant granulation tissue

Bleed easily and are often ulcerated

Develop after trauma, reaching a size of 1 to 2 cm within a few weeks

Robbins Basic Pathology

Cavernous hemangiomas

Large, dilated vascular channels

More infiltrative, frequently involve deep structures

Do not spontaneously regress

Sharply defined, unencapsulated

Large, cavernous blood-filled vascular spaces, separated by connective tissue stroma

Intravascular thrombosis, dystrophic calcification

Robbins Basic Pathology


Glomus Tumors (Glomangiomas)

Benign, painful tumors

Specialized smooth muscle cells of glomus bodies

Arteriovenous structures involved in thermoregulation

Distal portion of the digits, especially under the fingernails

Excision is curative

Bacillary Angiomatosis

Vascular proliferation in immunocompromised hosts (AIDS)

Opportunistic gram-negative bacilli of the Bartonella family

Skin, bone, brain, and other organs

Skin lesions are red papules and nodules, or rounded subcutaneous masses

Proliferation of capillaries lined by prominent epithelioid endothelial cells

Nuclear atypia and mitoses

The bacteria induce host tissues to produce HIF-1α, VEGF production and vascular proliferation

Cured by antibiotic treatment

Bacillary angiomatosis.

Robbins Basic Pathology

Bacillary angiomatosis.

B: Histologic features are those of acute inflammation and capillary proliferation. Inset, Modified silver (Warthin-Starry) stain demonstrates clusters of tangled bacilli (black)

Robbins Basic Pathology

Kaposi Sarcoma

Robbins Basic Pathology

Robbins Basic Pathology


Intermediate grade neoplasm

Sometimes resemble epithelial neoplasms morphologically

Excision is curative in a majority of the cases

40% of the tumors recur

20-30% metastasize

15% of patients die of their tumors


Malignant endothelial neoplasms

Highly differentiated tumors resembling hemangiomas to wildly anaplastic lesions difficult to distinguish from carcinomas or melanomas

Older adults

No gender bias

Can occur at any site, most often skin, soft tissue, breast, and liver

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Moderately differentiated angiosarcoma with dense clumps of atypical cells lining distinct vascular lumina

Immunohistochemical staining of angiosarcoma for the endothelial cell marker CD31

Robbins Basic Pathology

Vascular Intervention

Thrombosis, intimal thickening and atherosclerosis is seen after stent or grafts

Robbins Basic Pathology