Page 420 - Textbook of Pathology, 6th Edition

404 and characterised by acute and chronic occlusive
iii) The internal elastic lamina is often fragmented.
iv) There is eccentric or concentric intimal cellular inflammatory involvement. The disease affects chiefly men
proliferation causing marked narrowing of the lumen. The under the age of 35 years who are heavy cigarette smokers.
narrowed lumen may contain thrombus. The symptom-complex consists of intermittent claudication
v) Occasionally, only nonspecific inflammatory cell due to ischaemia manifested by intense pain affecting the
infiltrate consisting of neutrophils, lymphocytes and limbs, more commonly the legs. Eventually, gangrene of the
eosinophils is found throughout the arterial wall. affected extremities occurs requiring amputation.
ETIOPATHOGENESIS. Following possible mechanisms
Takayasu’s Arteritis (Pulseless Disease) have been suggested:
This is a form of granulomatous vasculitis affecting chiefly There is consistent association with heavy cigarette
the aorta and its major branches and hence is also referred to smoking. This has led to the hypothesis that tobacco products
as aortic arch syndrome. The disease affects chiefly young cause either direct endothelial damage leading to
women and is typically characterised by absence of pulse in hypercoagulability and thrombosis, or it is a result in
both arms and presence of ocular manifestations. Other hypersensitivity to tobacco products. In support is the
features referable to ischaemic effects from thrombotic demonstration of anti-endothelial cell antibodies (AECAs).
occlusion of vessels include myocardial infarction, congestive Genetic factors play a role as the disease has familial
heart failure and neurologic deficits. The etiology of occurrence and has HLA association. An increased
Takayasu’s arteritis is not known but the autoimmune prevalence is seen in individuals with HLA-A9 and HLA-B5
reaction to aortic tissue has been suggested as the possible antigens. It is seen more commonly in persons from Israel,
cause. Japan and in India.
Grossly, the aortic wall is irregularly thickened and intima Grossly, the lesions are typically segmental affecting small
wrinkled. The branches of major arteries coming off the and medium-sized arteries, especially of the lower
aortic arch have obliterated lumina. extremities. Involvement of the arteries is often
Histologically, the features are as under: accompanied with involvement of adjacent veins and
i) There is severe mononuclear inflammatory infiltrate nerves. Fibrous tissue cuff generally surrounds these three
involving the full thickness of the affected vessel wall. structures. Mural thrombi are frequently present in the
ii) The inflammatory changes are more severe in the vessels.
adventitia and media and there is perivascular infiltration Microscopically, the following changes are seen in
SECTION III
of the vasa vasorum. different stages of the disease:
iii) Granulomatous changes in the media with central i) In early stage, there is infiltration by polymorphs in all
necrosis and Langhans’ giant cells are found in many the layers of vessels and there is invariable presence of
cases. mural or occlusive thrombosis of the lumen (Fig. 15.14).
iv) Advanced lesions show extensive fibrosis of the media The appearance differs from atherosclerosis in having
and adventitia causing thickening in the vessel wall. microabscesses in the thrombi, proliferation of endothelial
cells, lack of lipid aggregates and presence of intact
Kawasaki’s Disease
internal elastic lamina.
Also known by more descriptive name of ‘mucocutaneous ii) In advanced stage, the cellular infiltrate is predomi-
lymph node syndrome’, it is an acute and subacute illness nantly mononuclear and may contain an occasional
Systemic Pathology
affecting mainly young children and infants. Kawasaki’s epithelioid cell granuloma with Langhans’ giant cells. The
disease is a febrile illness with mucocutaneous symptoms thrombi undergo organisation and recanalisation. In more
like erosions of oral mucosa and conjunctiva, skin rash and chronic cases, marked fibrosis of the media is present.
lymphadenopathy. The etiology is unknown; possible causes
considered are infectious, genetic, toxic and immunological. Miscellaneous Hypersensitivity Vasculitis
The most characteristic finding is the presence of multiple Various connective tissue diseases (e.g. rheumatoid arthritis,
aneurysms of the coronaries detected by angiography during ankylosing spondylitis and SLE), rheumatic fever, certain
life or observed at autopsy. Other vessels that may be malignancies and Henoch-Schönlein purpura are associated
involved are renal, mesenteric, hepatic and pancreatic with vasculitis. The type of vasculitis is generally of
arteries. hypersensitivity or allergic angiitis as already explained but
sometimes may resemble PAN.
Histologically, the picture is of panarteritis resembling Rheumatoid vasculitis affects chiefly the small and
PAN, characterised by necrosis and inflammation of the medium-sized arteries of multiple visceral organs in patients
entire thickness of the vessel wall. Therefore, some who have rheumatoid nodules of long duration. Vasculitis
consider Kawasaki’s disease as an infantile form of PAN.
in SLE affects mainly the small arteries of the skin.
Rheumatic vasculitis involves the aorta, carotid and
Buerger’s Disease (Thromboangiitis Obliterans)
coronary arteries and the visceral vessels. Usually, fibrinoid
Buerger’s disease is a specific disease entity affecting chiefly change and perivascular inflammation are seen rather than
small and medium-sized arteries and veins of the extremities typical Aschoff nodules (page 439).