Infectious Vasculitis Flashcards
Direct invasion of what agents may cause infectious vasculitis?
Pseudomonas
Aspergillus
Mucor
What is the general pathogenesis of infectious vasculitis?
Vascular invasion as part of localized tissue infection, or less commonly hematogenous spread
Septicemia or embolization from infective endocarditis
What conditions may result from infectious vasculitis?
Mycotic aneurysms = vascular infections weaken arterial walls
Thrombosis
Infarction
Inflammation induced thrombosis of meningeal vessels in bacterial meningitis can eventually cause infarction of underlying brain tissue
What are the DOs of blood vessel hyperreactivity?
Raynaud phenomenon
Myocardial vessel vasospasm
Describe what Raynaud Phenomenon is generally.
Excessive vasospasm of small arteries and arterioles, especially fingers and toes
“red, white, and blue” = proximal vasodilation, central vasoconstriction, and distal cyanosis
Describe Primary Raynaud Phenomenon.
Induced by cold or emotion; symmetric involvement of digits
Estimated 3-5% general population; YOUNG WOMEN
BENIGN course
Describe Secondary Raynaud Phenomenon.
Component of another arterial disease (SLE, scleroderma, thromboangiitis obliterans)
Asymmetric involvement of digits
Worsens with time
Describe Myocardial vessel vasospasm.
Excessive vasoconstriction of myocardial arteries or arterioles (“cardiac Raynaud”) - may cause ischemia or infarct
What is the pathogenesis behind Myocardial vessel vasospasm?
High levels of vasoactive mediators can precipitate prolonged myocardial vessel contraction
Usually caused by circulating vasoactive agents, which may be endogenous (epinephrine, pheochromocytoma), or exogenous (cocaine)
What is the outcome of Myocardial vessel vasospasm?
Sudden cardiac death
Takotsubo cardiomyopathy = “broken heart syndrome”, associated with emotional distress
What are varicose veins?
Abnormal dilation of veins with valvular incompetence, secondary to sustained intraluminal pressure
What Sx may you see with varicose veins?
Stasis, congestion, thrombus, edema, pain and ischemia of overlying skin (stasis dermatitis)
Poor wound healing and superimposed infections are common complications
Where do embolisms generally form in regards to varicose veins?
Embolism from thrombi of superficial lower extremity veins are RARE
They are more likely to form as DVTs (deep vein thrombosis)
What are esophageal varices? Why are they clinically important?
Portal HTN (often due to cirrhosis) opens portosystemic shunts which direct blood to veins at the gastroesophageal junction
Clinically important cause they may rupture
Portal HTN causes esophageal varies. What other conditions may it lead to?
Hemorrhoids = rectum
Caput medusa = periumbilical veins
What happens in caput medusae in relation to the abdominal wall?
In portal HTN, the umbilical vein (normally obliterated at birth) can dilate
Blood shunted from periumbilical veins –> umbilical vein –> abd wall
What are hemorrhoids?
Dilation of the venous plexus at the anorectal junction
Extremely common, and cause pain, bleeding, ulcers
What is thrombophlebitis?
Venous thrombosis and inflammation
Almost always (>90%) involves deep veins in the legs - can be completely asymptomatic
Pulmonary embolism is a serious consequence
What are the risks for DVT?
Single most important = prolong inactivity/immobilization
Systemic hypercoagulability
What is migratory thrombophlebitis?
Trousseau sign
Pts with cancer may experience hypercoagulability as a paraneoplastic syndrome
Particularly seen with mucin-producing adenocarcinomas (mucin through to be thrombogenic) = Associated with adenocarcinomas of lung, ovary, pancreas
Classic case - appear to one site, disappear, reappear elsewhere
What is Superior vena cava syndrome?
Neoplasms compress or invade SVC (bronchogenic carcinoma, mediastinal lymphoma, or aortic aneurysm)
What Sx does SVC syndrome produce?
Obstruction produces a characteristic clinical complex:
- Marked dilation of veins of head, neck, and arms w/ cyanosis
- Pulmonary vessels can also be compressed –> respiratory distress
What is inferior vena cava syndrome?
Neoplasms that compress or invade IVC or thrombosis of the hepatic, renal, or lower extremity veins that propagates cephalad
Hepatocellular carcinoma and renal cell carcinoma = tend to grow within veins, can ultimately occlude the IVC, and extend into the right atrium
What Sx does IVC syndrome produce?
IVC obstruction induces: Marked lower extremity edema
Distension of the superficial collateral veins of lower abd
Renal involvement –> massive proteinuria
What is lymphangitis?
Acute inflammation and spread of bacterial infection into lymphatics
What is the most common agent of lymphangitis?
Group A B-hemolytic streptococci
What Sx do you see with lymphangitis?
Red, painful subcutaneous streaks (inflamed lymphatics)
Painful enlargement of draining LN (lymphadenitis)
Can progress to cellulitis and focal abscesses; or bacteremia and sepsis
What is primary lymphedema?
Isolated congenital defect, of familial Milroy Dz (lymphatic agenesis or hypoplasia)
What is secondary or obstructive lymphedema?
Blockage of previously normal lymphatics
Ex: from Malignant tumor, surgical procedures (radical mastectomy with axillary node dissection), post irradiation fibrosis, filariasis, post inflamm thrombosis or scarring
Chylothorax, chylous ascites, chylopericardium
What is peau d’ orange (orange peel)?
Seen with secondary or obstructive lymphedema
Skin overlying breast cancer, draining lymphatics clogged with tumor cells
Describe vascular tumors, benign and malignant.
Benign tumors:
-Produce obvious vascular channels filled with blood cells lined by a monolayer of normal-appearing endothelial cells
Malignant tumors:
- More cellular, more proliferative
- Exhibit cytologic atypia
- Do not form well-organized vessels
- Endothelial derivation of neoplastic proliferations that don’t form distinct vascular lumina can usually be confirmed by immunohistochemical demonstration of endothelial cell-specific markers such as CD31 or vWF
What is ectasia?
Any local dilation of a structure
What is telangiectasia?
Permanent dilation of preexisting small vessels that form a discrete RED lesion - usually in the skin or mucous membranes
Congenital or acquired, not true neoplasms
Malformations or hamartomas
What is Nevus Flammeus?
Birthmark
Most common form of vascular ectasia
Light pink to deep purple flat lesion of head or neck composed of dilated vessels
Most regress spontaneously
Describe a Port wine stain.
Form of nevus flammeus
Grow during childhood, thicken, and don’t fade
Such lesions in distribution of trigeminal nerve = Sturge-Weber syndrome
Ipsilateral venous angiomas in the cortical leptomeninges, mental retardation, seizures, hemiplegia, skull radio-opacities
What is Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease)?
Autosomal dominant DO cause by mutation in genes that encode components of TGF-B signaling pathway
Malformations composed of dilated capillaries and veins that are present at birth
Lesions spontaneously rupture, causing epistaxis, GI bleeding, hematuria
Widely dist. over skin and oral mucous membrane + resp, GI, and GU tract
What are the benign vascular tumors?
Capillary hemangioma
Cavernous hemangioma
Pyogenic granuloma
Cavernous lymphangioma (Cystic hygroma) Simple (capillary) lymphangioma
Glomus tumor
Nevus flammeus
Spider telangiectasia
Hereditary hemorrhagic telangiectasis
Bacillary angiomatosis
What is a hemangioma? Where are the common sites? What happens with congenital hemangiomas?
Common tumors; localized increase in neoplastic blood vessels
Common sites = skin & mucous membranes of head & neck, and in liver
Congenital hemangiomas often regress
What is a capillary hemangioma?
Most common
Thin-walled capillaries, tightly packed together
What is a cavernous hemangioma?
Irregular, dilated vascular channels making a lesion with an indistinct border
More likely to involve deep tissue, more likely to bleed
What is a pyogenic granuloma (lobular capillary hemangioma)?
Type of capillary hemangioma (not pyogenic, not a granuloma)
Rapidly growing, often in oral mucosa (may ulcerate); 1/4 dev following trauma
Granuloma gravidarum (pregnancy tumor): gingiva of pregnant women
What is a simple lymphangioma?
Appear very similar to capillary hemangiomas, but w/o RBCs
Subcutis of head/neck and axillae
What is a cavernous lymphangioma cystic hydroma)?
Neck or axilla of children
Can be large (up to 15 cm)
Large cavernous lymphangiomas of the neck seen in turner syndrome
What is a Glomus tumor?
Aka Glomangioma, paraganglioma
Benign tumors arising from glomus bodies, and most often appear in distal fingers
Of smooth muscle origin rather than endothelial
PAINFUL
What is bacillary angiomatosis?
Vascular proliferation in response to gram (-) Bartonella bacilli
Occurs on the skin of immunocompromised patients
- lesions are localized, forming red papules
- micro = proliferation of capillaries with plump endothelial cells
- bacteria can be identified with PCR, or visualized with a Warthin-Starry stain
- macrolide abx are effective
What are the Intermediate-Grade (Borderline) vascular tumors?
Epithelioid hemangioendothelioma
Kaposi Sarcoma
What is Epithelioid Hemangioendothelioma?
Neoplastic endothelial cells are plump and cuboidal, resemble epithelium
Vascular channels may be difficult to recognize
Variable clinical behavior, with metastasis in 20-30%
What is Kaposi Sarcoma caused by?
HHV8
What are the 4 distinct clinical forms of KS?
Aids-associated KS
Classic KS
Endemic African KS
Transplant-assoc KS
What is AIDS-associated KS?
Most common form seen in US
Most common AIDS-related malignant tumor
May spread to lymph nodes and viscera
What is classic KS?
Older men from middle eastern, Mediterranean, or eastern European descent
Not associated with HIV
Tumors localized to skin
What is endemic African KS?
Not associated with HIV.
Pts <40
Can involve lymph nodes
What is transplant-associated KS?
Not associated with HIV, but with T-cell immunosuppression
Can spread to LN and viscera
What are the malignant vascular tumors?
Angiosarcoma
Hemangiopericytoma
What is a Angiosarcoma? Who does it affect more? How can it be induced?
Malignant endothelial tumor
Age = older, M=F
Can be induced by radiation exposure; can arise in setting of lymphedema (upper extremity after radial mastectomy)
What is hepatic angiosarcoma associated with?
Arsenic, pesticides, thorotrast (contrast agent), polyvinyl chloride
Where do angiosarcomas occur? What is the survival rate?
May occur anywhere, but most common sites = skin, soft tissue, breast, and liver (CD31 marker)
Locally invasive and may metastasize
5 yr survival around 30%
What is the pathology behind vascular intervention?
Therapeutic intervention that injures the endothelium also tends to induce intimal thickening by recruiting smooth muscle cells promoting extracellular matrix deposition, analogous to atherosclerosis
What are types of endovascular stenting?
Balloon angioplasty
Coronary stents
Drug-eluting stents
What is a balloon angioplasty?
Rupture of occluding plaque
Limited dissection produced
Abrupt reclosure can result form extensive dissection; thus 90% of angioplasties are followed by stent placement
What is a coronary stent?
Expandable tubes of metallic mesh
Due to endothelial injury may induce thrombosis
Long term = proliferative in-stent restenosis (1/3 pts within 6-12 mo)
What are Drug-eluting stents? What are the drugs?
Leach antiproliferative drugs to block smooth muscle activation
Decrease restenosis at 1 yr by 50-80%
Paclitaxel and Sirolimus
What are vascular replacements?
Synthetic or autologous vascular grafts
Synthetic large bore works for aorta, but small bore fail due to thrombosis or intimal hyperplasia at junction of the graft with the native vasc.
What can you use for small bore grafts (coronary arteries)?
Saphenous vein = 50% patency at 10 yrs
Left internal mammary arteries = 90% patency at 10 yrs
