Basics of a Blood Vessel
Endothelial cells:

- Line blood vessels.
- CD34 positive â Marker for endothelium
- Contain Weibel-Palade bodies.
- Weibel-Palade bodies contain:
- W for von Willebrand factor.
- P for P-selectins.
Vasculitis


Chapel Hill classification (based on affected vessel size).
- Large vessel vasculitis.
- Medium vessel vasculitis.
- Small vessel vasculitis.
- (Cryoglobulinemia â Small vessel vasculitis)
Large Vessel Vasculitis
- Mnemonic: The two T's
- Temporal Arteritis
- Takayasu Arteritis
Temporal Arteritis (Giant Cell Arteritis - GCA)

- Affected Vessel:
- Most commonly superficial temporal artery.
- nodular and very tender.
- Age: Occurs in individuals older than 50 years.
- "Giant cell" because it occurs in "giants" (older people).
- Symptoms:
- Most Common: Headache (throbbing, unbearable, localized, unilateral).
- Most Specific: Jaw claudication or jaw pain.
- Most Dangerous:Â Loss of vision (Involvement of Ophthalmic Artery)
- Ophthalmic manifestation
- AION (Anterior ischemic optic neuropathy)
- M/c/c â non-arteritic AION
- A/w
- GCA â arteritic AION
- Posterior ciliary Artery supplying anterior part of ON is affected
- Amourosis fugax (curtain falling)
- Features
- Sudden painless vision loss
- Swollen Pale Optic disc
- RAPD
- Gold Standard:
- Biopsy â superficial temporal artery > 1 cm (bcz skip lesions are present)
- Microscopy:
- Shows multi-nucleated giant cells and granulomas.
- VVG stain is used.
- Mnemonic: Giant Cell â Very Very Giant Stain is used
- Characteristic:
- Fragmentation of internal elastic lamina.


- Treatment:Â
- Start steroids ASAPÂ
- prevent vision loss.
- Do not wait for pathology reports.
Takayasu Arteritis (Aortic Arteritis / Pulseless Disease)

- Age: Occurs in individuals less than 50 years of age.
- Affected Vessel:
- M/c branches of arch of aorta â Left Subclavian artery
- Renal Artery Stenosis
- Coronary vessel â MI
- Microscopy/Pathology:
- Shows intimal thickening â very narrow lumen.
- Called "pulseless disease"
- Clinical Presentation:
- Young individuals
- Weak pulse: Especially in upper limb (e.g., radial artery).
- Rx
- Steroids
- Abatacept
- Mechanism:
- Inhibits interaction of T-cells and APC
- â T cell activation
- â CD 80/86
- (Co stimulation inhibitor)
- Can be used in Takayasu Arteritis
- (similar efficacy to steroids)
- A Bat and ball â co stimulation
- Takatsubo â Heart dilatation
- Takayasu â Artery constriction â Pulseless disease
Renal artery stenosis


- Affects the ostium.
- Young patient (without a family history of hypertension)
- 1st investigation is renal Doppler (Image 1)
- has a slow and blunted uptake.
- i.e. pulsus parvus et tardus waveform (Image 2)
- Normal renal artery has a quick upstroke.
- 2nd investigation is CT-angiography or MR-angiography.
- Gold standard procedure is digital subtraction angiography (DSA).
Medium Vessel Vasculitis
- Mnemonic: PAN Khata Bacha
- PAN: Polyarteritis Nodosa
- KA: Kawasaki Disease
- BA: Buerger's Disease
Polyarteritis Nodosa (PAN)

- middle-aged females â HBsAg positive.
- 30% of cases:Â HBsAg (Australia antigen)Â +
- Involved Vessels:
- Most common: Renal vessels (but no glomerulonephritis).
- Never Affected:Â Pulmonary vessels.
- PANOOO â Pulm Art Not Involved
- (Polyarteritis Nodosa does not involve Pulmonary vessels).
- Guy Got Hep B () after going to Australia (Australia antigen) â beat his Kidney (Renal vessels) with a PAN ()
- Microscopy: Shows fibrinoid necrosis.
Kawasaki Disease (M/C in Kids)


Tongue appearance | Seen in |
Strawberry tongue | ⢠Kawasaki disease ⢠Scarlet fever |
Beefy tongue | ⢠Vitamin B12 deficiency |
Magenta red/ Geographical tongue | ⢠Vitamin B2 deficiency |
Case scenario
- A 4-year-old child presents with fever and rash for 6 days, along with red eyes and tongue and swelling of hands.
- Age: Typically occurs in children less than 5 years of age.
Diagnostic Criteria (CRASH BURN criteria):
- Fever >39°C for more than 5 days + at least 4 of the following:
- At least four of five criteria: CRASH
- Conjunctivitis (B/L Non Purulent)
- Rash â Polymorphous
- Adenopathy (non tender)
- Strawberry tongue
- Red, fissured lips
- Note: Strawberry tongue also in scarlet fever.
- Hands and feet Erythema that later leads to desquamation â edema
Pathogenesis:
- Associated with anti-endothelial cell antibodies.
Blood Test Findings:
- Thrombocytosis (increased platelet count).
- Leukocytosis, elevated ESR or CRP.
Complications:
- M/c â Myocarditis
- Most dangerous
- Coronary artery aneurysm
- Giant >8mm (>1cm) in diameter
- Risk â resemble infection
- Male sex
- Fever âĽ14 days
- Elevated ESR and CRP
- WBC count >12,000/mmÂł
- Hematocrit (PCV) <35%
- Serum sodium <135 mEq/L
- Can lead to aneurysm or myocardial infarction (heart attack) in child
- Rare but potentially fatal
Treatment
- Aimed at preventing coronary artery aneurysm
- IVIG
- if given within first 10 days, reduces the risk of coronary artery aneurysm
- Corticosteroids
- if persistent fever despite IVIg
- ASPIRIN
- High dose aspirin reduces risk of thrombosis, given until subside fever
- Low dose aspirin is given until ECHO is performed at 6 weeks to exclude aneurysm
- Reyeâs syndrome
- Acute Liver Failure
- Microvesicular steatosis
Buerger's Disease (Thromboangiitis Obliterans - TAO)



Feature | Buergerâs Disease (Thromboangitis Obliterans) | Atherosclerosis |
Gender | M > F | M = F |
Age | 3rd Decade â most important | ⼠5th Decade |
Risk Factors | Smoking | Smoking, Alcohol, Type A Personality, Hyperlipidemia |
Limbs Affected | Lower Limbs > Upper Limbs | Lower Limbs > Upper Limbs |
Affected Structures | Artery, Vein, Nerve Small to Medium Arteries and veins (totally obliterated). Never Affected: Lymphatics. | Arteries Large to Medium |
Progression | Distal â Proximal | Proximal â Distal |
Clinical Symptoms: | ⢠Initial: Intermittent claudication, usually leg claudication (pain during walking). ⢠Later: Pain at rest (due to nerve involvement). | ă
¤ |
Other Features | - Confirmatory Test: Muscle Biopsy â â Shows Neutrophilic microabcess - Imaging: Corkscrew Collaterals | - |
Management | 1. Stop Smoking 2. Pentoxyphylline 3. Conservative Amputation 4. Lumbar Sympathectomy â Only if Rest Pain Present â If B/L, Conserve L1 Ganglion on One Side to Prevent Impotence | 1. Angioplasty (First line) 2. Bypass (Best) : Using grafts |
Small Vessel Vasculitis
- M/C associated with connective tissue diseases
- HSP
- 3 ANCA vasculitis
Henoch-SchĂśnlein Purpura (HSP)
Vasculitis - Henoch-SchĂśnlein Purpura (HSP)




Case Scenario
- A child presents with abdominal pain, hematuria, and palpable purpura over the leg.
- Small vessel vasculitis
- Often preceded by infections/drugs
Diagnostic criteria
- Palpable purpura with presence of 1 or more of:
- Diffuse abdominal pain
- Arthritis or arthralgia
- Any biopsy showing IgA deposition
- Renal involvement
Organs affected (PAARpura):
- P â Purpura (commonly on lower limbs).
- A â Arthralgia.
- A â Abdominal pain.
- Complication - intussusception
- Submucosal hematoma
- Main indication for giving steroid â GI bleed
- R â Renal involvement (e.g., hematuria).
- Kidney is the most common affected organ.
- Glomerulonephritis is seen in 1/3 of patients.
- Proteinuria
- haematuria,
- RBC casts
Biopsy:
- Leukocytoclastic vasculitis with IgA-containing immune complexes


Skin Presentation:
- Palpable purpura (felt)
- Thrombocytopenia is Absent.
- Lower legs and buttocks
- Painful
Treatment:
- Most of the cases are self-limiting.
- if not self-limiting
- DOC: Corticosteroids
- Dapsone
- Colchicine
NOTE:
- Palpable purpura â Vasculitis
- Non palpable purpura â Bleeding, clotting, thrombocytopenia
ANCA-Associated Vasculitis
(Pauci-immune Vasculitis)
- ANCA:Â Anti-Neutrophilic Cytoplasmic Antibody.
Types of ANCA:

Feature | C-ANCAÂ (Cytoplasmic ANCA) | P-ANCAÂ (Perinuclear ANCA) |
New Name | PR3-ANCA Anti Proteinase 3 ANCA CPR: C â PR3 | MPO-ANCA |
Appearance | Green color throughout cytoplasm See â Anal hole | Green color only around nucleus P â Puu â Flowe app. |
ă
¤ | - Wegners | - Churg strauss - Wegners - Microscopic Polyangiitis - UC >> CDxx - Primary Sclerosing Cholangitis. |
ă
¤ | See (C Anca) doing PR 3 (PR3) times with a Vegetable (Wegners) | Cholangitis â Colitis â chrug strauss â Polyangitis |
Granulomatosis with Polyangiitis (GPA)
(formerly Wegener's Granulomatosis)



- Necrotizing vasculitis with granulomas.
- Strawberry gingiva.

- ENT TriadÂ
- Ears: Otitis media.
- Nose: Nasal septal perforation / Saddle nose
- Throat:Â Strawberry gums
- Upper respiratory tract (URT) involvement:
- Recurrent sinusitis.
- Epistaxis.
- Lower respiratory tract (LRT) involvement:
- Hemoptysis.
- Cavitations (due to lung blood supply damage).

- Kidney:
- Hematuria.
- A/w
- RPGN Type 3 (with Microscopic polyangitis)
- PAUCI IMMUNE
- Flea bitten kidney
- Note:
- In TB, cavity in upper lobe of lungs.
- In this condition, multiple small cavities due to necrotizing vasculitis.
- Workup:
- Shows both C-ANCA > P-ANCA.
- against cytoplasmic antigen â anti-proteinase 3

- Treatment:
- Cyclophosphamide + Mesna
- Differentiation from Goodpasture syndrome:
- Goodpasture:
- Hemoptysis + hematuria (basement membrane damage in lung and kidney).
- Wegenerâs:
- Lung cavitation + URT involvement + hematuria
Microscopic Polyangiitis (MPA)

- aka Leukocytoclastic VasculitisÂ
- broken white blood cells in biopsies
- Key Feature:Â Does not show granulomas.
- P-ANCA.
Feature | Polyarteritis Nodosa (PAN) | Microscopic Polyangiitis (MPA) |
HBsAg | Positive | Not HBsAg positive |
Glomerulonephritis | No | Occurs |
Pulmonary Vessels | Never involved | Involved |
Microscopy | Fibrinoid necrosis | Leukocytoclastic vasculitis |
Eosinophilic Granulomatosis with Polyangiitis (EGPA)
(formerly Churg-Strauss Syndrome)


- Eosinophilic Granulomatosis with Polyangiitis (EGPA).
- Key Feature: Shows lots of eosinophils.
- ANCA Type:Â P-ANCA.
- Other diseases with P-ANCA:
- Ulcerative Colitis (more than Crohn's disease).
- Primary Sclerosing Cholangitis.
- Microscopic Polyangiitis
- Wegnerâs
Vascular Tumors

- Divided into benign, intermediate, and malignant.
Benign Tumors



Capillary Hemangioma

- Clinical: Occurs on superficial sites (skin, mucosa).
- Microscopy: Shows extremely tiny, small blood vessels.
Cavernous Hemangioma
- M/c benign tumour of liver.
- Association:Â
- VHL Syndrome (Von Hippel-Lindau Syndrome).
- Involves chromosome deletion 3P.
- Clinical:Â
- Deep-seated (organs like liver).
- Usually asymptomatic.
- Microscopy:
- Shows very large and dilated blood vessels.
- CT:
- Peripheral nodular enhancement.

- No surgical intervention required.
- Mnemonic: Hemand (Hemangioma) oru deep large cave (cavernous) il poi, 3 Pakal (3p) thamasichu â Very hot locationil (VHL)
Pyogenic Granuloma

- Misnomer:Â
- Not associated with pus/bacteria (pyogenic);Â
- does not show granulomas.
- Other Names:
- Granuloma Gravidarum (partially correct, seen in pregnancy);Â
- Pregnancy Tumor (most accurate).
- Clinical: Seen in pregnant ladies (reddish lesion).
- Oral cavity or fingertips.
- Microscopy: Known as Lobular Capillary Hemangioma (LCH).
- Tiny capillaries arranged in lobules/groups.
Lymphangioma
- Location: Occurs in the neck.
- Association:
- When in neck:Â Cystic hygroma.
- Seen in Turner Syndrome (45XO).
Glomus Tumor


- Location: Always on nail beds (subungual).
- Symptom: Excruciating pain (pain to the power infinity).
- Origin: Arises from glomus bodies (arteriovenous anastomoses at fingertips).
- Regulate temperature (thermoregulation).
Bacillary Angiomatosis


- Cause:Â Bartonella henselae.
- Bartonella henselae also causes cat scratch disease.
- Stain: Positive for Warthin-Starry silver stain (organism appears black).
- Clumps of neutrophils with bacilli seen
Cat scratch disease
- Bacillary Angiomatosis
- Stellate cells seen
Intermediate Tumors


- Association: Seen in HIV-positive individuals
- Gamma virus
- Most Common Sites:
- First:Â
- Seen on legs
- Presents with deep red to bluish papules and nodules
- Second:Â Lymph node.

- M/c lid malignancy in HIV
- Microscopy:
- Shows spindle cells.
- IHC (Immunohistochemistry):Â
- LANA (latency associated nucleic acid) positive.
- Kakkusil pokumbo sing LALA (LANA) and SPIN (Spindle)
Malignant Vascular Tumors
Angiosarcoma

- Most Common Organ:
- Most commonly in the liver.
- Most common cause for malignant cancer of heart in adults
- Causes:Â VAT chemicals:
- V: Vinyl chloride (plastics, polyvinyl chloride).
- A: Arsenic (pesticides).
- T: Thorotrast (thorium-based contrast dye, old radiology use).
- Thorotrast,
- Thorotrast linked to
- HCC,
- cholangiocarcinoma &
- renal cell carcinoma.
- Angiosarcoma (VAT â Plastic)
- Histology:
- Anastomosing vascular channels.
- Highly pleomorphic cells.
- IHC markers:
- von Willebrand factor.
- Factor VIII.
- VEGF.
- CD31 (PCAM)
- Mnemonic: Plastic (Plastic industry) ittu Vaattan (VAT) poyapo Liveril blood cancer vannnu
Hemangiopericytoma

- Microscopic Appearance:
- Blood vessels appear like staghorn or fishhook blood vessels.

Behcetâs Disease



Â
- Systemic vasculitis
- Anti alpha enolase Ab
- Pathergy â Pathetic diagnosis â misunderstood young patient with recurrent oral and genital ulcers
- Misunderstood a young as 51 () yr old nolan (Enolase) in bus ()
Triad of Features


- Relapsing uveitis (mainly posterior)
- Recurrent genital ulcers
- Recurrent oral ulcers
Features (Oro-Oculo-Genital Syndrome)
- Most common diagnostic feature:
- Recurrent oral ulceration.
- Painful, like aphthae, recurrent
- Recurrence at least thrice in any 12 months.

- PLUS TWO OF:
- Genital ulcers:
- Female: Vulva ulcer
- Male: Scrotal ulcer
- not penile ulcer as in STDs like H. ducreyi, syphilis
- Eye lesions:
- Anterior uveitis.
- Posterior uveitis.
- Hypopyon
- Retinal vasculitis
- Skin lesions:
- Erythema nodosum
- Pseudofolliculitis or papulopustular lesions, OR
- Acneform nodules in post-adolescent patients not on corticosteroids.
- Positive pathergy test
Other Systemic Involvement:
- Non-erosive, asymmetric oligoarthritis
- Multi-system: Pulmonary, cardiac, GI, neurological
Pathergy Test/ Pathergy phenomenon:
- Positive because it can cause systemic vasculitis
- Not a diagnostic criteria
- Type 4 Hypersensitivity reaction
- Procedure:
- Sterile needle puncture on forearm with hypodermic cutting edge.
- Normal response:
- bleeding, clotting, mark disappears in 2-3 days.
- Behcetâs response:
- After 48 hours, formation of sterile pustule

Complications:
- Pulmonary artery aneurysm possible.
- Rupture: Lethal complication.
- Note: Pulmonary artery not involved in polyarteritis nodosa.
Management:
- Corticosteroids
- Ocular involvement:
- Azathioprine.
Mnemonic:
- Bus on a path â Pathergy test
- Oro occulo genital â On bus



