Page 421 - Textbook of Pathology, 6th Edition

405

Figure 15.14 Buerger’s disease (Thromboangiitis obliterans). There is acute panarteritis. The lumen is occluded by a thrombus containing
microabscesses.

Raynaud’s Disease and Raynaud’s Phenomenon ANEURYSMS
Raynaud’s disease is not a vasculitis but is a functional DEFINITION
vasospastic disorder affecting chiefly small arteries and
arterioles of the extremities, occurring in otherwise young An aneurysm is defined as a permanent abnormal dilatation
healthy females. The disease affects most commonly the of a blood vessel occurring due to congenital or acquired CHAPTER 15
fingers and hands. The ischaemic effect is provoked primarily weakening or destruction of the vessel wall. Most commonly,
by cold but other stimuli such as emotions, trauma, hormones aneurysms involve large elastic arteries, especially the aorta
and drugs also play a role. Clinically, the affected digits show and its major branches. Aneurysms can cause various ill-
pallor, followed by cyanosis, and then redness, corresponding effects such as thrombosis and thromboembolism, alteration
to arterial ischaemia, venostasis and hyperaemia respectively. in the flow of blood, rupture of the vessel and compression
Long-standing cases may develop ulceration and necrosis of neighbouring structures.
of digits but occurrence of true gangrene is rare. The cause
of the disease is unknown but probably occurs due to CLASSIFICATION
vasoconstriction mediated by autonomic stimulation of the
affected vessels. Though usually no pathologic changes are Aneurysms can be classified on the basis of various features:
observed in the affected vessels, long-standing cases may A. Depending upon the composition of the wall:
show endothelial proliferation and intimal thickening. 1 True aneurysm composed of all the layers of a normal The Blood Vessels and Lymphatics
vessel wall.
Raynaud’s phenomenon differs from Raynaud’s disease in
having an underlying cause e.g. secondary to arthero- 2. False aneurysm having fibrous wall and occurring often
sclerosis, connective tissue diseases like scleroderma and from trauma to the vessel.
SLE, Buerger’s disease, multiple myeloma, pulmonary B. Depending upon the shape: These are as under
hypertension and ingestion of ergot group of drugs. (Fig. 15.15):
Raynaud’s phenomenon like Raynaud’s disease, also shows 1. Saccular having large spherical outpouching.
cold sensitivity but differs from the latter in having structural 2. Fusiform having slow spindle-shaped dilatation.
abnormalities in the affected vessels. These changes include 3. Cylindrical with a continuous parallel dilatation.
segmental inflammation and fibrinoid change in the walls 4. Serpentine or varicose which has tortuous dilatation of the
of capillaries. vessel.

Figure 15.15 Common shapes of aneurysms of various types.