118: Vascular Tumors Flashcards
What are the two broad categories into which vascular anomalies are divided according to the ISSVA classification?
Vascular anomalies are divided into vascular malformations and vascular tumors.
What distinguishes infantile hemangiomas (IHs) from other vascular tumors and malformations?
Infantile hemangiomas are distinguished by their unique growth pattern, which includes a rapid proliferative phase followed by slower involution.
What is the most significant risk factor for the development of infantile hemangiomas?
The most significant risk factor for infantile hemangioma development is low birth weight, with a 40% risk increase for every 500 g decrease in birth weight.
What is the typical growth pattern of infantile hemangiomas during the early proliferative phase?
During the early proliferative phase, infantile hemangiomas exhibit rapid nonlinear growth, with the peak growth period occurring between 5.5 and 7.5 weeks of age.
What percentage of infantile hemangiomas have completed all growth by 5 months of age?
80% of infantile hemangiomas have completed all growth by 5 months of age.
What are the clinical features that are critical in the diagnosis of infantile hemangiomas?
A clinical history marked by characteristic proliferation and involution is critical in the diagnosis of infantile hemangiomas.
What is the typical color change observed during the involution of infantile hemangiomas (IHs)?
The typical color change during involution of IHs is from a dull red to gray or milky-white, followed by flattening and softening.
What percentage of infantile hemangiomas have completed involution by 3.5 to 4 years of age?
More than 90% of infantile hemangiomas have completed involution by 3.5 to 4 years of age.
How do superficial infantile hemangiomas differ from deep infantile hemangiomas in terms of residual skin changes after involution?
Superficial infantile hemangiomas are more likely to develop residual skin changes following involution compared with deep infantile hemangiomas, with an odds ratio of 8.4.
What classification is used for cutaneous infantile hemangiomas based on tumor depth and distribution?
Cutaneous infantile hemangiomas can be classified based on tumor depth (superficial, deep, combined/mixed) and distribution (localized, segmental, indeterminate, multifocal).
What is the association between segmental infantile hemangiomas and the risk of complications?
Segmental infantile hemangiomas are 11 times more likely to experience complications and 8 times more likely to receive treatment than localized hemangiomas, even when controlled for size.
What are the clinical features of combined infantile hemangiomas?
Combined infantile hemangiomas have clinical features of both deep and superficial hemangiomas.
What is the significance of the anatomic location of infantile hemangiomas in relation to risk factors?
The anatomic location of infantile hemangiomas is one of the most important factors affecting risk, with involvement of the central face, periocular area, neck, mandibular region, and perineum indicating possible increased risk of complications.
What are the complications associated with infantile hemangiomas (IHs)?
Complications of infantile hemangiomas can include:
- Ulceration
- Severe bleeding (less than 1% of cases)
- Scarring
- Pain
- Infection
- Additional complications may involve airway obstruction, congestive heart failure, and visual compromise.
Approximately 12% of all IHs are complex and may require specialist referral, with outcomes dependent on the timing of referral and intervention.
Which segments are associated with specific anomalies in segmental infantile hemangiomas?
The following segments are associated with specific anomalies:
Segment | Associated Anomalies |
|———|———————|
| Fronto-temporal (S1) | Cerebral, cerebrovascular, and ocular anomalies |
| Maxillary (S2) | Less frequently associated with extracutaneous involvement |
| Mandibular (S3) | Airway IH, ventral developmental defects, cardiovascular abnormalities |
| Frontonasal (S4) | High-risk territory of the nose, including nasal tip, with risk of cerebral and cerebrovascular involvement |
What is PHACE syndrome and its associations?
PHACE syndrome is a neurocutaneous association with facial segmental infantile hemangiomas (IHs). Key points include:
- It is sometimes referred to as PHACES to denote additional associations like sternal defects.
- Up to 90% of PHACE cases are in girls.
- Up to one-third of patients with facial segmental IHs with a surface area ≥ 22 cm² meet criteria for PHACE syndrome.
- The fronto-temporal (S1) and mandibular (S3) segments are most highly associated with PHACE.
What are the common extracutaneous features associated with PHACE syndrome?
Common extracutaneous features associated with PHACE syndrome include:
- Congenital vascular anomalies (most common)
- Cerebral vascular anomalies (occur in >90% of cases)
- Cardiac abnormalities (up to 67% of cases)
- Dysplasia, stenosis, hypoplasia, and agenesis of major cerebral and cervical vessels
- Coarctation of the aorta reported in 19% to 30% of cases
- Structural brain anomalies in approximately 40% of PHACE patients
- Arterial ischemic stroke, often presenting with seizure or hemiparesis.
What is LUMBAR syndrome and its associated risks?
LUMBAR syndrome describes the constellation of lower body hemangiomas and other cutaneous defects. It is associated with:
- Risk factors for spinal anomalies
- Bony anomalies
- Genitourinary anomalies
Segmental IHs on the lower body, particularly involving the perineum or lumbosacral area, are significant risk factors for these associated anomalies.
A 2-month-old infant with a segmental IH on the face is suspected of having PHACE syndrome. What extracutaneous anomalies should you evaluate for?
Evaluate for cerebral vascular anomalies, cardiac abnormalities, structural brain anomalies, ocular anomalies, and endocrine abnormalities.
A 5-month-old infant with a large IH on the face is suspected of having PHACE syndrome. What cardiac anomaly is most commonly associated?
Coarctation of the aorta is reported in 19% to 30% of PHACE cases and is frequently associated with aberrant origin of both subclavian arteries.
A 3-month-old infant with a large IH on the scalp is suspected of having PHACE syndrome. What structural brain anomalies should you evaluate for?
Evaluate for dysplasia, stenosis, hypoplasia, and agenesis of major cerebral and cervical vessels, as well as structural brain anomalies.
A 2-month-old infant with a large IH on the face is suspected of having PHACE syndrome. What ocular anomalies should you evaluate for?
Evaluate for posterior segment anomalies (e.g., morning glory disc anomaly, optic nerve hypoplasia, persistent fetal vasculature, or retinal vascular anomalies) or microphthalmia.
A 3-month-old infant with a large IH on the scalp is suspected of having PHACE syndrome. What endocrine abnormalities should you evaluate for?
Evaluate for hypothyroidism, hypopituitarism, growth hormone deficiency, headaches, and speech and language delays.
A 5-month-old infant with a large IH on the face is suspected of having PHACE syndrome. What structural brain anomalies are associated?
Structural brain anomalies occur in approximately 40% of PHACE patients and include dysplasia, stenosis, hypoplasia, and agenesis of major cerebral and cervical vessels.
What are the common extracutaneous abnormalities associated with myelopathy in infants with infantile hemangiomas?
The most commonly associated extracutaneous abnormality is myelopathy, which can present as tethered cord or lipomyelo(meningo)cele. MRI is strongly recommended for evaluation.
What is the risk of amblyopia in infants with periocular hemangiomas, and what should be done for patients with these hemangiomas?
Infants with periocular hemangiomas are at risk for amblyopia, which is the most common ocular complication, occurring in 40% to 60% of untreated cases. Any patient with a hemangioma in the periocular area should have a prompt formal ophthalmologic evaluation with repeat visits during the rapid and late proliferative phases.
What is the significance of segment 3 hemangiomas in the beard area of infants?
Segment 3 hemangiomas involving the preauricular, mandibular, chin, and neck skin carry a 60% risk of causing symptomatic airway disease. They often present with the insidious onset of biphasic stridor between weeks 4 and 12 of life, necessitating prompt evaluation by a pediatric otolaryngologist.
What are the characteristics and risks associated with multifocal infantile hemangiomas?
Approximately 15% of infants will have more than 1 hemangioma. Infants with multifocal IH have an increased risk of noncutaneous IH. Screening with hepatic and abdominal ultrasound is recommended for infants presenting with 5 or more cutaneous hemangiomas.
What are the potential complications of hepatic hemangiomas in infants?
Hepatic hemangiomas can be focal, multifocal, or diffuse. They are frequently asymptomatic but can cause high-output congestive heart failure, hypothyroidism, or hepatic failure. Diffuse infantile hepatic hemangiomas are less common and associated with high morbidity and mortality, potentially leading to abdominal compartment syndrome and severe hypothyroidism.
What is the most common complication of infantile hemangiomas and its prevalence?
Ulceration is the most common complication of infantile hemangiomas, occurring in greater than 20% of infants during the proliferative phase, with a median age of onset of 4 months. It most commonly occurs in large or segmental IHs and at sites exposed to moisture and friction.
A 4-month-old infant with a periocular IH is at risk for amblyopia. What is the recommended course of action?
Prompt formal ophthalmologic evaluation and treatment should be initiated urgently to prevent long-term effects, including permanent blindness.
A 6-month-old infant with a large IH on the liver is diagnosed with diffuse hepatic hemangiomas. What complications should you monitor for?
Monitor for high-output congestive heart failure, hypothyroidism, and hepatic failure. Aggressive thyroid hormone replacement and systemic β-blocker therapy may be required.
A 6-month-old infant with a large IH on the lower body is suspected of having LUMBAR syndrome. What extracutaneous anomalies should you evaluate for?
Evaluate for spinal, bony, and genitourinary anomalies, as well as arterial anomalies and limb hypotrophy.
A 6-month-old infant with a large IH on the liver is diagnosed with diffuse hepatic hemangiomas. What treatment options are available?
Systemic β-blocker therapy, systemic corticosteroids, or embolization may be required. In life-threatening cases, liver transplantation may be considered.
What is the significance of early gray-white discoloration in infants younger than 3 months?
Early gray-white discoloration in infants younger than 3 months is a sensitive marker of impending ulceration.
What are the essential components of local wound care for ulcerations in infants?
Local wound care for ulcerations should include:
- Bio-occlusive dressings that do not adhere well near the mouth or in diaper areas.
- Thick applications of petrolatum-based ointments.
- Pain management with occlusive dressings, oral acetaminophen, and topical lidocaine ointment.
What are the treatment options for severe ulcers that remain unhealed after 2 to 3 weeks?
For severe ulcers that remain unhealed after 2 to 3 weeks, more aggressive therapy is warranted, which may include:
- Systemic β-blocker therapy.
- Topical β-blocker (e.g., topical timolol maleate).
- Pulsed-dye laser (PDL).
- Other options like becaplermin 0.01% gel, intralesional and systemic corticosteroids, and early excision.
What is the role of GLUT1 in the pathogenesis of infantile hemangiomas (IH)?
GLUT1 is a red blood cell glucose transporter protein and is the most reliable histologic marker of IH. It is expressed in all stages of IH and is absent in normal cutaneous vasculature, suggesting a unique role in the pathogenesis of IH.
How does hypoxia contribute to the development of infantile hemangiomas?
Hypoxia is postulated to trigger neovasculogenesis in infants, and low birth weight, which is the most significant risk factor for IH, is known to be associated with hypoxia. Additionally, GLUT1 is upregulated in the setting of hypoxia, indicating its role in IH development.
What are the histologic features that differentiate between proliferating and involuted infantile hemangiomas?
Histologic features that differentiate between proliferating and involuted IH include the presence of endothelial progenitor cells (HemEPCs) in proliferative IH, which are absent in the involution phase. Additionally, the expression of the primitive cell marker CD133+ is noted in proliferative IH.
A 3-month-old infant with a large IH develops ulceration. What is the first-line treatment?
Local wound care, barrier protection, and pain control are essential. Bio-occlusive dressings or thick applications of petrolatum-based ointments can be used.
A 4-month-old infant with a large IH on the perineum develops ulceration. What additional complications should you consider?
Consider secondary infection, pain, and scarring. Systemic antibiotics may be required if deep or persistent infection is suspected.
A 4-month-old infant with a large IH on the perioral area develops ulceration. What is the first sign of impending ulceration?
Early gray-white discoloration in patients younger than 3 months is a sensitive marker of impending ulceration.
A 4-month-old infant with a large IH on the perineum develops ulceration. What additional treatment options are available for severe ulcers?
Systemic β-blocker therapy, topical β-blocker (e.g., topical timolol maleate), and pulsed-dye laser (PDL) therapy are options for severe ulcers.
A 4-month-old infant with a large IH on the perioral area develops ulceration. What pain management options are available?
Pain can be minimized with an occlusive dressing, oral acetaminophen with or without codeine, and the use of very small amounts of topical lidocaine ointment.
What is the primary clinical method for diagnosing infantile hemangiomas (IH)?
The diagnosis of IH is almost exclusively clinical, based on the physical examination and clinical history.
What imaging technique is preferred for evaluating infantile hemangiomas due to its lack of ionizing radiation?
Ultrasound imaging is preferred.
What is the first sign of impending ulceration in an infant with infantile hemangioma (IH)?
Early gray-white discoloration in patients younger than 3 months is a sensitive marker of impending ulceration.
What imaging technique is preferred for evaluating infantile hemangiomas due to its lack of ionizing radiation?
Ultrasound imaging is preferred for evaluating infantile hemangiomas due to its lack of need for sedation, lack of ionizing radiation, and relatively low cost.
What are the histopathological features of infantile hemangiomas during the proliferative phase?
During the proliferative phase, IH is characterized by a well-defined mass of capillaries arranged in lobules, lined with plump endothelial cells with enlarged nuclei and abundant cytoplasm, and surrounded by pericytes in the absence of smooth muscle cells.
What laboratory tests should be performed in infants with significant hepatic hemangiomas?
Infants with significant hepatic hemangiomas should have thyroid function evaluated, including triiodothyronine (T3) and thyroid-stimulating hormone, as thyroxine (T4) levels may initially remain normal.
What is the significance of GLUT1 immunostaining in the diagnosis of infantile hemangiomas?
GLUT1 immunostaining is positive in the endothelial cells lining IH capillaries at all stages of IH growth, distinguishing IH from other vascular tumors and all vascular malformations.
What diagnostic imaging is recommended for a 6-week-old infant with a rapidly growing red lesion on the scalp?
Doppler ultrasound is recommended as it is a high-flow lesion and appears as a well-defined solid mass with increased vascular flow. It is non-invasive, does not require sedation, and is cost-effective.
What syndrome should you screen for in a 3-month-old infant with a segmental IH on the lower back?
Screen for LUMBAR syndrome, which includes spinal, bony, and genitourinary anomalies. MRI/MRA of the lumbosacral spine, pelvis, and/or lower extremity is recommended.
What diagnostic tests should be performed for a 2-month-old infant suspected of having PHACE syndrome?
Perform MRI/MRA of the head, neck, and chest, a formal ophthalmologic evaluation, and an echocardiogram to evaluate for PHACE syndrome.
What additional evaluation is necessary for a 1-year-old child with a history of IH found to have hypothyroidism?
Perform a hepatic ultrasound to evaluate for hepatic hemangiomas, as they can cause hypothyroidism due to high levels of Type III iodothyronine deiodinase activity.
What imaging is necessary for a 6-month-old infant with a large IH on the lower body suspected of having LUMBAR syndrome?
MRI/MRA of the lumbosacral spine, pelvis, and/or lower extremity is necessary to evaluate for LUMBAR syndrome.
What diagnostic tests should be performed for a 3-month-old infant with a large IH on the scalp suspected of having PHACE syndrome?
Perform MRI/MRA of the head, neck, and chest, a formal ophthalmologic evaluation, and an echocardiogram to evaluate for PHACE syndrome.
What is the most important factor affecting the prognosis of complicated infantile hemangiomas (IH)?
The most important factor affecting prognosis in complicated IH is the timing of specialist referral for management, including initiation of therapy and workup as necessary.
What is the recommended approach for managing small infantile hemangiomas (IH)?
For the majority of small IH, the recommended approach is active nonintervention with close observation and follow-up, especially during the first few months of life.
What medication is approved by the FDA for the treatment of complicated infantile hemangiomas?
Propranolol is the only medication approved by the FDA for the treatment of complicated infantile hemangiomas.
What are the key criteria for considering beta-blocker treatment initiation for infantile hemangiomas?
Key criteria for considering beta-blocker treatment initiation for IH include: 1. Facial deformity 2. Active or impending functional impairment 3. Early prevention of anticipated permanent sequelae 4. Mitigation of the need for surgery.
What are the potential treatment options for infantile hemangiomas that warrant intervention?
Potential treatment options for infantile hemangiomas that warrant intervention include: - Pharmacologic treatments - Laser therapy - Surgical interventions.
What are the common side effects of propranolol in the treatment of infantile hemangiomas?
Common side effects of propranolol include: - Sleep disturbance - Acrocyanosis - Asymptomatic transient decrease in blood pressure or heart rate. Rarely observed potential important adverse effects include: - Hypoglycemia - Symptomatic hypotension or bradycardia - Wheezing - Bronchospasm - Diarrhea.
What is the recommended dosing strategy for propranolol in treating infantile hemangiomas?
The dosing strategy for propranolol typically involves: 1. Starting at 1 mg/kg/day in 2 divided doses. 2. Increasing by 0.5 mg/kg/day increments every 3 to 7 days. 3. Target dose between 2 and 3 mg/kg/day, with most practitioners using 2 mg/kg/day.
What factors should be considered when determining a patient’s candidacy for propranolol treatment?
Factors to consider include: - Family history to ensure absence of congenital heart disease, arrhythmia, and maternal connective tissue disease. - Young age (infants as young as 5 weeks). - Comorbid medical conditions (e.g., respiratory or cardiovascular issues). - Inadequate social support or preexisting concerns for blood glucose.
How does topical timolol compare to aqueous timolol solution in terms of systemic absorption?
Topical timolol gel-forming solution has less systemic absorption compared to aqueous timolol solution. Factors affecting systemic absorption include: - Application site (mucosa, ulceration, and areas under occlusion increase absorption). - Application size and patient size (neonates and premature infants have greater absorption due to increased surface-area-to-volume ratios).
What are the short-term complications associated with systemic corticosteroids in the treatment of infantile hemangiomas?
Short-term complications of systemic corticosteroids include: - Cushingoid faces (71%) - Personality changes (irritability/fussiness) (29%) - Gastric irritation (21%) - Fungal infection (oral or perineal, 6%) - Diminished gain of weight.
What precautions should be taken during initiation of propranolol in a 5-week-old infant with a segmental IH?
Use the lowest effective dose, consider a slower dose titration, and administer the medication in 3 divided doses to avoid significant alterations in peak blood levels.
What are the common side effects of propranolol in a 3-month-old infant with a large IH?
Common side effects include sleep disturbance, acrocyanosis, and asymptomatic transient decrease in blood pressure or heart rate.
What is the expected mechanism of action of propranolol in a 3-month-old infant with a large IH?
Propranolol causes lesional capillary vasoconstriction, angiogenesis inhibition, and induction of apoptosis, leading to IH regression.
What side effects should you monitor for in a 3-month-old infant with a large IH started on propranolol?
Monitor for sleep disturbance, acrocyanosis, hypoglycemia, symptomatic hypotension or bradycardia, wheezing, bronchospasm, and diarrhea.
What dosing regimen is recommended for propranolol in a 2-month-old infant with a large IH?
Start at 1 mg/kg/day in 2 divided doses and increase by 0.5 mg/kg/day increments every 3 to 7 days to a target dose between 2 and 3 mg/kg/day.
What molecular mechanisms contribute to the efficacy of propranolol in a 3-month-old infant with a large IH?
Propranolol causes lesional capillary vasoconstriction, angiogenesis inhibition, and induction of apoptosis, leading to IH regression.
What is the typical dosing regimen for propranolol in a 2-month-old infant with a large IH?
Dosing is typically started at 1 mg/kg/day in 2 divided doses and increased by 0.5 mg/kg/day increments every 3 to 7 days to a target dose between 2 and 3 mg/kg/day.
What are the common complications associated with high-dose corticosteroid treatment in children?
Common complications include: - Hypertension - Steroid-induced myopathy - Immunosuppression - Transient adrenal insufficiency. Additionally, children taking more than 2 mg/kg/day of prednisone for longer than 14 days may have a deficit in cell-mediated immunity.
What is the role of intralesional corticosteroids in the treatment of infantile hemangiomas (IHs)?
Intralesional corticosteroids can be effective for select, relatively small, localized IHs located in high-risk sites such as the lip, nasal tip, cheek, and ear. They have shown: - Greater than 50% reduction in volume in superficial IHs. - Adverse events occurred in 6.4% of patients, including cushingoid appearance, cutaneous atrophy, and anaphylactic shock.
What are the indications for surgical intervention in infantile hemangiomas during infancy?
Indications for surgical intervention during infancy include: 1. Anatomically favorable site amenable to resection. 2. Contraindication or failure of pharmacotherapy. 3. High risk of ultimately necessary resection with similar scar regardless of timing.
What are the findings from studies comparing PDL treatment and observation for infantile hemangiomas?
In a prospective, randomized, controlled study: - PDL with epidermal cooling showed significant color improvement but unchanged total surface area and echo depth by 12 months. - Another study with PDL without cooling and observation groups showed comparable results of (near-) complete resolution at age 1 year, with a trend toward increased hypopigmentation and textural change in the PDL group.
What is the current stance on the use of interferon-α and vincristine for treating infantile hemangiomas?
Interferon-α and vincristine are no longer advocated for treating infantile hemangiomas due to: - Established efficacy and more favorable side-effect profile of beta blockers. - Interferon-α carries a notable risk of neurotoxicity, specifically spastic diplegia.
What surgical options are available for a 2-year-old child with a residual fibrofatty mass after IH involution?
Surgical excision can be performed to reconstruct affected adjacent structures, resect residual excess skin or fibrofatty tissue, or revise scars. Decisions are often made between 3 and 5 years of age.
What treatment options are available for a 2-year-old child with a history of IH and residual telangiectasias?
Pulsed-dye laser (PDL) therapy can be used to diminish residual telangiectasias and erythema after IH involution.
What is the recommended age for surgical intervention for a 2-year-old child with residual fibrofatty tissue after IH?
Surgical intervention is often recommended between 3 and 5 years of age, even if involution is not complete.
What laser therapy is recommended for a 2-year-old child with residual telangiectasias after IH?
Pulsed-dye laser (PDL) therapy is recommended to diminish residual telangiectasias and erythema after IH involution.
What is the appropriate threshold age for involution of infantile hemangiomas (IHs) and why?
Four years serves as an appropriate threshold age as most IHs have completed involution and children develop self-awareness, long-term memory, and self-esteem.
What are the three major subtypes of congenital hemangiomas based on their natural history?
The three major subtypes of congenital hemangiomas are: 1. Rapidly involuting congenital hemangioma (RICH) 2. Noninvoluting congenital hemangioma (NICH) 3. Partially involuting congenital hemangioma.
What are the distinguishing pathologic features of congenital hemangiomas?
The distinguishing pathologic features of congenital hemangiomas include: - Lobules of capillaries with plump endothelial cells and pericytes - Densely fibrotic stroma containing hemosiderin deposits - Focal lobular thrombosis - Sclerosis - They are GLUT1 negative, unlike infantile hemangiomas.
What are the indications for treatment of congenital hemangiomas?
Indications for treatment of congenital hemangiomas include: - Ulceration - Impairment of vital function - Congestive heart failure - Excision, with or without preoperative embolization, should be considered for ulceration and post-involutional skin changes if disfiguring.
What is the clinical significance of RICHs in relation to thrombocytopenia?
RICHs can be associated with mild to moderate thrombocytopenia and a coagulopathy characterized by elevated fibrin degradation products and low fibrinogen in the neonatal period.
How can you differentiate a congenital hemangioma from IH in a neonate?
Congenital hemangiomas are GLUT1 negative, unlike IH, and do not proliferate postnatally. They are classified as RICH, NICH, or partially involuting congenital hemangiomas based on their natural history.
What subtype of congenital hemangioma is most likely in a neonate presenting with thrombocytopenia and coagulopathy?
The lesion is likely a rapidly involuting congenital hemangioma (RICH), which can be associated with mild to moderate thrombocytopenia and coagulopathy.
What subtype of congenital hemangioma is most likely in a neonate presenting with a well-circumscribed, indurated mass?
The lesion is likely a noninvoluting congenital hemangioma (NICH), which presents as a well-circumscribed, round to oval, indurated or raised soft-tissue mass.
What subtype of congenital hemangioma is most likely in a neonate presenting with a raised, violaceous tumor with large, radiating veins?
The lesion is likely a rapidly involuting congenital hemangioma (RICH), which often appears as a raised, violaceous tumor with large, radiating veins.
What are the clinical features of TA (angioblastoma of Nakagawa)?
TA typically presents as: - A subtle stain-like area that later thickens - A large, plaque-like, infiltrated, red or dusky blue-purple lesion - An exophytic, firm, rubbery, violaceous, cutaneous nodule - Tenderness and overlying hyperhidrosis may occur.
What is a rapidly involuting congenital hemangioma (RICH)?
The lesion is likely a rapidly involuting congenital hemangioma (RICH), which often appears as a raised, violaceous tumor with large, radiating veins.
What are the clinical features of TA (angioblastoma of Nakagawa)?
TA typically presents as:
- A subtle stain-like area that later thickens
- A large, plaque-like, infiltrated, red or dusky blue-purple lesion
- An exophytic, firm, rubbery, violaceous, cutaneous nodule
- Tenderness and overlying hyperhidrosis may occur.
- TA is usually solitary, but multifocal cases have been reported.
What is the Kasabach-Merritt phenomenon (KMP) and its association with TA and KHE?
KMP refers to the presence of platelet trapping within a vascular tumor, leading to:
- Profoundly severe thrombocytopenia (typically <30,000/μL)
- Associated microangiopathic hemolytic anemia
- Consumption of clotting factors resulting in low fibrinogen and elevated d-dimers.
KMP is more common with KHE but can also develop in TA. It is now recognized as a complication almost exclusively of TA and KHE, not infantile hemangiomas (IH).
What are the recommended management options for TA?
Management options for TA include:
1. Excision
2. Compression
3. Laser therapy
4. Topical or systemic corticosteroids
5. Propranolol
6. Chemotherapy
What are the clinical features of KHE (Kaposiform Hemangioendothelioma)?
KHE is characterized by:
- An infiltrative, aggressive tumor classified as locally aggressive or borderline.
- Presentation as a brown-red stain at birth that thickens and becomes purpuric, or as plaques or deep-seated nodules and bulky tumors.
- Involvement of skin and musculature, often affecting extremities, joints, trunk, head, and neck.
- Deeper viscera can be affected, but KHE does not occur in the liver.
What is the epidemiology of KHE?
KHE is a rare vascular tumor with:
- An estimated prevalence of 0.91 cases per 100,000 children.
- Presentation at birth or development in early childhood, with 60% presenting as neonates and 93% in infancy.
- Rare adult cases reported, with three-quarters involving the skin.
What is the histological characteristic of Kaposiform Hemangioendothelioma (KHE)?
KHE is characterized by infiltrative nodules and sheets of spindled endothelial cells with minimal atypia and infrequent mitoses lining slit-like or crescentic vessels containing hemosiderin. Edema, microthrombi, fibrosis, and atypical appearing lymphatic vessels can also be observed.
What is the management approach for KHE complicated by KMP?
Management of KHE complicated by KMP requires more aggressive intervention than KHE without coagulopathy. The approach includes:
1. Complete surgical excision when feasible.
2. Systemic corticosteroids as first-line treatment, often combined with vincristine.
3. Adjunctive therapies like ticlopidine and aspirin.
4. Arterial embolization before surgery to decrease bleeding risk.
5. Oral sirolimus showing promise in reversing coagulopathy.
6. Avoidance of platelet transfusions unless active bleeding occurs.
What are the typical clinical features of Pyogenic Granuloma (PG)?
PG typically presents as a solitary, red, rapidly growing papule or nodule, often with a subtle collarette of scale. Common locations include the cheek or forehead, but it can affect virtually any body site, including mucous membranes. PG often develops an eroded surface with subsequent bleeding, and it does not typically involute spontaneously.
What is Multifocal Lymphangioendotheliomatosis with Thrombocytopenia (MLT) and its characteristics?
MLT, also known as cutaneovisceral angiomatosis with thrombocytopenia, is characterized by:
- Multiple cutaneous vascular papules and plaques that are usually congenital.
- Development of new lesions over time.
- Intermittent thrombocytopenia and lesions in the GI tract, leading to GI bleeding.
- Involvement of other sites such as bones, synovium, lungs, liver, spleen, and brain.
- Skin biopsy shows thin-walled vessels and hobnailed endothelial cells.
What is the prognosis for patients with Multifocal Lymphangioendotheliomatosis with Thrombocytopenia?
The prognosis for patients with MLT varies based on the extent of disease and bleeding complications. A meta-analysis reported a 65% mortality rate associated with this condition.
What is the clinical significance of the presence of ‘hobnail’ endothelial cells in PILA/Dabska tumors?
The presence of ‘hobnail’ endothelial cells inside tumoral vessels is the sine qua non of PILA/Dabska tumors, indicating a definitive diagnosis of this low-grade vascular tumor.
What are the histopathological features of Retiform Hemangioendotheliomas?
Retiform Hemangioendotheliomas demonstrate a retiform pattern of long, arborizing blood vessels lined by monomorphic hobnail endothelial cells. They often show a prominent lymphocytic infiltrate and a focal presence of hyaline collagenous core comprising papillae.
What is required for the diagnosis of Composite Hemangioendothelioma?
The diagnosis of Composite Hemangioendothelioma requires the identification of at least two hemangioendothelioma variants. Epithelioid and retiform variants are most commonly observed, along with possible foci of spindle-cell hemangioma or angiosarcoma-like foci.
What are the typical clinical features of Targetoid Hemosiderotic Hemangioma?
Targetoid Hemosiderotic Hemangioma typically presents as a violaceous papule surrounded by a pale rim and peripheral ecchymotic halo, which fades with time. Lesions are usually found on the trunk or extremities and consist of dilated vascular channels within intraluminal papillary projections dissecting into collagen bundles in the subcutis.
What are the characteristic histologic findings of Congenital Eccrine Angiomatous Hamartoma?
Congenital Eccrine Angiomatous Hamartoma is characterized by closely packed eccrine sweat glands associated with dilated capillaries, a few dysplastic venous channels, and a dense collagenous matrix. It typically presents with ill-defined plaques and increased lanugo hair and sweating at the site of the lesion.
