Chapter 147- Vascular malformation II Flashcards
Most common complication of lymphatic anomalies in 20% of cases
Infection
Macro cystic LM can be diagnosed in utero as early as the ___ trimester of pregnancy
First
Most LMs are diagnosed during ___
Infancy, before the age of 2 years
Localized morphogenic errors of lymphatic vessels
Lymphatic malformations
Condition wherein lymph fluid accumulates the interstitial tissue
Primary lymphedema
Primary lymphedema can be divided into
Congenital (Milroy disease) Late onset (Meige disease)
It is a combined capillary-venous-lymphatic malformation associated with hypertrophy of the the affected limb
Klippel Trenaunay syndrome
It is characterized by geographic widespread CM associated with lymphatic vesicles
Klippel-Trenaunay syndrome
Pathognomonic for Klippel Trenaunay syndrome
Persistence of embryonic vein located on the lateral side of the thigh
CLOVES is an eponym for
Congenital Lipomatous Overgrowth with Vascular malformation, Epidermal nevi, and Skeletal anomalies
It is characterized by progressive asymmetric hypertrophy, multiple truncal lipomatous masses with parasoibal fast flow or slow flow vascular anonalies, epidermal nevus or nevi, acral lesions, and skeletal or spinal anomalies
CLOVES syndrome
Rare condition in which LMs can invade several organs such as mediastinum, lungs, pleura, GIT, bones, and soft tissue (pleura effusion, ascites, malabsorption)
Generalized Lymphatic Anomaly
Aggressive rare lymphatic disorder characterized by progressive demineralization and destruction of bones, which are replaced by lymphatic vessels and capillaries; characterized by painful pathological fractures
Gorham-Stout syndrome or vanishing bone disease
Microcysts <1cm are previously termed as ___; ill-defined and often invade adjacent structures
Lymphangioma circumscriptum
Macrocysts >1 cm in diameter are previously termed as ___; soft, well-defined, multilobulated mass
Cystic hygroma
Capillary- lymphatic malformation, pink- to - bluish red in color, slightly raised, hyperkeratotic, located on an extremity
Angiokeratoma circumscriptum
Circumscribed, dark red, hyperkeratotic plaques on distal extremities
Angiokeratoma of Mibelli
Very common hyperkeratotic blue black papules on the scrotum of elderly men
Angiokeratoma of Fordyce
Present at birth, with swelling of bilateral dorsum of feet; with family history of lymphedema
Milroy disease
Other features associated with congenita lymphedema
(37%) hydrocele (23%) prominent veins (14%) upslanting toenails (10%) papillomatosis (4%) urethral abnormalities in males
Major complication of Klippel Trenaunay syndrome
Cellulitis
Pulmonary embolism can occur in
Klippel Trenaunay syndrome (persistent embryonic vein) CLOVES syndrome (ectatic thoracic vein)
Visceral LM can cause (2)
Protein losing enteropathy
Hypoalbuminemia
Most commonly associated with microcystic LM
Facial asymmetry esp. of mandible
Lymphatic malformations (KTS, CLOVES) are caused by mutations in
PI3K/AKT/mTor signaling pathway
Milroy disease, as well as sporadic hydrops fetalis and generalized subcutaneous edema, is caused by loss-of-function mutation in
VEGFR3
Lymphedema distichiasis is caused loss of function mutation in
FOXC2 transcription factor
Lymphedema associated with microcephaly, with or without chorioretinopathy or developmental delay is caused by mutation in
KIF11
Hypotrichosis-lymphedema-telangiectasia is AD-AR mutation caused by mutations in
SOX18
Emberger syndrome is caused by mutations in
GATA2
It is an AR disorder characterized by generalized lymphatic dysplasia characterized by intestinal lymphangiectasia with severe and progressive lymphedema of limbs, genitalia, and the face
Hennekam syndrome
Hennekam syndrome is caused by mutations in
CCBE1
Specific lymphatic markers
Podoplanin
D2-40
VEGR3
Histologically
- Single or multiple lymphatic cysts surrounded by a thick fibrous membrane that do not communicate with each other
- Abnormalities in primary peripheral lymphatic capillaries, collecting lymphatic vessels, or lymphatic valves, and lymphovenous valves
- Dilated, flat, endothelium-lined channels of variable wall thickness
- No blood cells are seen in these spaces
- Extensive fibrosis is often present
- Macrocystic LM
2,5. Lymphedema
3,4. Lymphatic malformations
Best study to show bone involvement
CT
For CLOVES, ff up every ___ is warranted due to progressive overgrowth during infancy
6 months
In contrast to VM, LM are
Noncompressible
In cases of vulvar involvement, it is important to rule out acquired lymphangiectasia caused by
Radiotherapy
Crohn disease
Most likely DDx of lymphatic malformation
Infantile hemangioma
Regression is commonly seen post ___ due to ____
Infection; postinflammatory autosclerosis
Gorham-Stout syndrome is lethal in ___%
16
Patients with KTS or CLOVES need preTx of ___ before any surgery and continued ___ postop to reduce risk of pulmonary embolism
LMWH of 100 anti-Xa/kg/day; 10-30 days
For extensive LMs resistant to standard treatment
Rapamycin
Lymphedema is best treated with (3)
Elastic stockings
Massage
Pneumatic compression devices
Treat dermal LMs with oozing
NdYAG laser or carbon dioxide laser photocoagulation
Examples of sclerosing agents
STS Pure ethanol OK432 (streptococcus pyogenes: picbanil) Doxycycline Bleomycin
Extract from a killed strain of Streptococcus pyogenes
OK432
Congenital, fast flow malformations that can be occult until puberty
Arteriovemous malformation
Most severe and devastating malformation that is difficult to treat
AV malformation
AV fistula
It is characterized by the presence of a nidus, epicenter of a lesion composed of direct communications between multiple feeding arteries and draining veins
AV malformation
Autosomal dominant disorder with spontaneous recurrent epistasis, telangiectasia, hepatic or pulmonary AVMs
Hereditary Hemorrhagic Telangiectasia
Hereditary Hemorrhagic Telangiectasia has the Curacao triad:
- Multiple cutaneous and mucosal telangiectases, often on the mucosal lip
- Epistaxis
- Positive family history
In ___% of HHT, they present with spontaneous recurrent epistaxis
90%
In 30% of HHTs, they present with ___
Hepatic, pulmonary, cerebral AVM
Initial manifestation of HHT
Recurrent epistaxis
Patients are at higher risk for stroke and brain abscess due to normal filtering function of lung is lost
HHT
The prevalence of brain AVM is ___ fold higher in patients with HHT1; and ___fold in patients with HHT2
1000
100
HHT is caused by alterations in ___ signaling pathway
TGFB
Genes mutated in HHT1; HHT2
Endoglin (ENG); Type III TGFB
ACVRL1 (ALK1); Type 1 TGFB
Successfully used to reduce the frequency and duration of nosebleeds in HHT
Thalidomide
It is a sporadic, syndromic AVM located in the centrofavial, hemifacial area with oculo-orbital and cerebral involvement
Bonnet-Dechaume-Blanc
Wyburn- Mason
Intracerebral AVMs are common with epistaxis, exophthalmos, hemianopia, and mental retardation
Bonnet-Dechaume- Blanc
Wyburn- Mason
Sporadic, syndromic AVM that associates cutaneous and spinal cord AVMs of the same metamere
Cobb syndrome
It manifests in childhood with sudden onset of back or lower extremity pain associated with sensory disturbance
Cobb syndrome
It is a large, congenital, cutaneous red vascular stain on an extremity in association with soft tissue and skeletal hypertrophy of the affected limb and underlying multiple AV microfistulas
Parkes Weber syndrome
Treatment to control leg length discrepancy of Parkes Weber syndrome
Epiphysiodesis
It is an autosomal dominant disorder that includes patients with macrocephaly, penile freckling, multiple developmental venous anonalies in the brain, multifocal fast flow VMs, and increased risk of malignancy
Phosphatase and Tensin Homolog Hamartoma Tumor Syndrome
Syndromes associated with Phosphatase and Tensin Homolog Hamartoma Tumor Syndrome
Bannayan-Riley-Ruvalcaba
Cowden syndrome
Cutaneous, faint, red to purple, ill-defined masses with a thrill, a bruit, or a pulsation of increased amplitude
AV malformations
1/3 of AVMs are present at __; 1/3 at ___; the rest at
At birth
At childhood or puberty
In adulthood d/t trauma and hormonal changes
70% of AVMs occur in
Face
Schobinger stage classification:
1- red stain with bruit and pulses of increased amplitude
2 - prominent and tortuous veins
3 - darker, painful veins which ulcerate and bleed
4 - cardiac failure
In ___% of CM-AVM1, and ___% of CMAVM2, ak intracerebral or intraspinal AVM is present
23%
13%
Patients with CM-AVM can exhibit intrauterine life threatening intracerebral bleeding due to ___ aneurysmal malformation
Vein of Galen
Sporadic extracranial AVMs are caused by somatic mutations of
MAP2K1 (MEK)
Brain AVM is caused by mutaion in
KRAS
__ determines the extent of AVM and differentiate AVMs from hemagiomas
MRI
Pathognomonic for AVM
Flow voids
Dx modality needed to determine nidus before starting any Tx
Arteriography
Can differentiate between slow flow CM vs fast flow AVM
Dopller ultrasonography
Mismanagement of AVM can lead to __
Amputation
Focus of management of AVM
Control evolution of malformation rather than cure
Synthetic matrix metalloproteinase inhibitor used to treat extensive AVMs with decrease in pain, bruits
Marimastat
It is used in unresectable stage 3 AVMs
Thalidomide
Done only in unresectable complicated AVM
Superselective embolization
AVf is usually the result of
Trauma
There is no risk of visceral AVM in
CM-AVM
10-15% of CM-AVM have __ phenotype affecting LE or UE
Parkes Weber phenotype
Common feature of facial AVM
Bony hypertrophy
PTEN regulates __ activity
PI3K-AKT pathway
___ have equatorial feeding arteries and peripheral veins but no true AV shunting
Hemangiomas
Embolization is only curative for
AV fistula
Ff up for __ years is mandatory after any Tx of AVM with Doppler or MRI
5 years
Done in unresectable, complicated AVM
Super selective embolization
Ligature of __ stimulates recruitment of new feeding arteries and expands the malformation
Proximal arteries