Chapter 188 - Pediatric vascular tumors Flashcards
Types of pediatric vascular tumor
1) infantile hemangioma 2) congenital hemangioma 3) kaposiform hemangioendothelioma 4) pyogenic granuloma
Pediatric vascular tumor that can also be seen at any age
Pyogenic granuloma
Pediatric vascular tumour that’s considered intermediate and not fully benign
KHE
Differentiating vascular tumour from malformation
Tumours have proliferative endothelium
Infantile hemangioma cell type
Progenitor cells that are supposed to develop into blood vessels Multipotent hemangioma-derived stem cells
Likely triggers of infantile hemangioma
hypoxia –> endothelial proliferation
Natural course of infantile hemangioma
Involute before age 4 tumour replaced by fat cells also derived from same stem cells
Factors associated with infantile hemangioma
1) caucasian 2) premature low birth weight 3) female
Most common location of lesions in infantile hemangioma
1) head & neck 2) trunk 3) extremity
Infantile hemangioma that are solitary lesions (rate)
80%
Appearance of infantile hemangioma tumour
if superficial dermis = bright red if deeper = bluish or normal
Chance of visceral hemangioma if > 5 cutaneous
16%
Most common visceral hemangioma location
liver
Infantile hemangioma course
Growth - birth to 9 month; first 8 weeks rapid
Age 5 - 80% volume growth
Involution 1-4 years
Disease associated with diffuse infantile hemangioma
1) replace liver parenchyma –> massive hepatomegaly
2) IVC compression
3) hypothyroidism (from deiodinase inactivation of thyroid hormone)
Hypothyroidism complication in children
Mental retardation
Segmental midline lumbosacral region infantile hemangioma associated with
33% spinal anomaly
1) tethered cord
2) lipoma
3) intraspinal hemangioma
Lower body infantile hemangioma associated with
LUMBAR
1) urogenital anomalies or ulceration
2) myelopathy
3) bone deformities
4) anorectal malformation
5) arterial and renal anomalies
mostly girls
Segmental plaquelike infantile hemangioma of the face associated with
PHACES syndrome
1) posterior fossa brain malformation (72%)
2) hemangioma
3) arterial anomalies
4) coarctation of aorta and cardiac defects
5) eye abnormalities
6) sternal clefting or supraumbilical raphe
Mostly female
Risk of PHACE syndrome in all infantile hemangioma
3%
Congenital hemangioma differentiate from infantile hemangioma
1) no post-natal growth
2) solitary usually 2-20 cm
Classic lesion of congenital hemangioma
1) red violaceous color
2) course telangiectasia
3) central pallor
4) peripheral pale halo
Congenital hemangioma distribution in body
mostly in extremity
Gender distribution of congenital hemangioma
equal sex distribution
Classification of congenital hemangioma based on involution
1) rapidly involuting
2) partially involuting
3) non-involuting
Rapid involuting congenital hemangioma time frame for involution
Birth and most gone by 7-14 months
Skin appearance after involution of congenital hemangioma
1) atrophic skin
2) lack underlying subcutaneous adipose tissue (unlike IH)
Staining marker for infantile hemangioma
GLUT 1
Noninvoluting congenital hemangioma typical location
Head/neck 43%
Extremity 38%
torso 19%
Large rapidly involuting congenital hemangioma can cause
thrombocytopenia
Characteristic of a kaposiform hemangioendothelioma
1) > 5cm in diameter +/- hair
2) 60% in neonatal and 90% by infancy
3) locally invasive but not metastatic
4) profound thrombocytopenia (Kasabach-Merritt)
5) reddish purple with ill-defined border
Epidemiology of kaposiform hemangioendothelioma
Equal gender distribution
1/100000
Distribution of kaposiform hemangioendothelioma
Head/neck 40%
Truck/extremity 30%
Pyogenic granuloma characteristic
1) lobular capillary hemangioma
2) solitary red papule 6.5 mm
3) rapid growth with stalk
4) bleeds and ulcerates
Epidemiology of pyogenic granuloma
Male:female 2:1
mean age onset 7 years
less likely at older ages
Location of pyogenic granuloma in the skin
90% cutaneous
12% mucous membrane
Causes of pyogenic granuloma
1) trauma
2) insect bite
3) viral infection
4) dermatologic disorder
Distribution of pyogenic granuloma in body
Head/neck 62%
trunk 19%
UE 13%
LE 5%
Ultrasound of infantile hemangioma
1) well-circumscribed hypervascular mass
2) low resistance arterial waveform
3) venous drainage
MRI of infantile hemangioma in proliferative phase
1) parenchymal mass with dilated vessels and signal void
2) isointense on T1
3) hyperintense on T2
4) enhances homogeneously after admin of contrast
MRI of involuting infantile hemangioma
1) lobular with adipose tissue and less vessels
2) signal void or enhancement
Microscopic characteristics of infantile hemangioma in proliferative phase
1) tightly packed capillaries
2) plump endothelial cells
3) minimal intervascular stroma
Microscopic characteristics of infantile hemangioma in involution stage
1) reduced capillaries
2) increased stroma
3) increased fibrofatty tissue
MRI findings on KHE
1) infiltrative lesions
2) hypertense on T2
3) enhances with contrast
4) subcutaneous stranding
5) ill-defined boarders
6) prominent vessels with hemosiderin (signal voids)
Histopathology of KHE
1) lobules of spindled lymphatic endothelial cells
2) glomeruloid appearance
3) vessels with thrombi and hemosiderin
4) tumor immuno stain for lymphatic markers D240 and PROX1
Microscopic characteristics of pyogenic granuloma
1) exophytic mass with narrow stalk
2) normal number of mast cells (not like IH)
3) immature capillaries interspersed with fibroblastic tissue superficially
4) proliferating capillaries in lobular pattern deep
Rate of skin ulceration in IH
16%
Treatment of IH
1) conservative
2) topical antibiotic and vaseline
3) topical lidocaine
4) topical corticosteroid (clobestasol
5) timolol application
6) Propranolol if not improving (stops 90% of tumor growth)
Contraindication to systemic beta blocker for treating IH
1) reactive airway disease
2) congenital heart disease
3) glucose abnormalities
Systemic drugs for IH
1) beta blocker
2) steroid
3) interferon or vincristine (high side effect like spastic diplegia)
Surgical treatment for IH
1) embolization
2) pulsed dye laser therapy
3) excision of lesion
Managing of congenital hemangioma
1) self limiting if rapidly involuting
2) surgical resection if non-involuting
Kasabach-Merritt phenomenon
Profound thrombocytopenia < 25
consumptive coagulopathy
life threatening in 12-24% of the time
Goals of treating Kaposiform Hemangioendothelioma
1) prevent complication of Kasabach-Merritt
2) minimize fibrosis
3) reduce chronic pain
4) reduce stiffness and contractures
Treatment for Kasabach-Merritt
1) corticosteroid (10% effective)
2) vincristine (90%)
3) interferon (50%)
