54 Vascular Malformations Flashcards
What are the four major classification schemes for vascular lesions, and what is the most useful and currently used nomenclature?
What are the four major classification schemes for vascular lesions, and what is the most useful and currently used nomenclature?
- Descriptive
- Anatomic-physiologic (microscopic)
- Embryologic
- Biologic behavior
Mulliken and Glowacki published a landmark paper in 1982 simplifying the nomenclature of vascular anomalies by classifying them based on cellular turnover and histology, which is most useful in the diagnosis, management, and prognosis of these lesions.
- Vascular tumors or infantile hemangiomas, characterized by rapidly enlarging endothelial proliferations that spontaneously involute.
- Vascular malformations are structural anomalies that are subcategorized based on channel type (capillary, venous, arterial, lymphatic, or combinations of these), present at birth and are characterized by growth proportional to the child. Unlike an infantile hemangioma, there is no cellular proliferation and instead there is progressive dilation of vascular channels.
What is the most common tumor of infancy and what is the classic presentation?
What is the most common tumor of infancy and what is the classic presentation?
Hemangioma is the most common tumor of infancy with an incidence of 1% to 2.6% at birth and ≈10% by one year of age. Eighty percent are noted within the first month of life, typically presenting at 2 to 4 weeks of life. The female to male ratio is 3 : 1 and 60% occur in the head and neck. Superficial lesions are bright red or crimson whereas deeper lesions may have a bluish hue. Hemangiomas have a very characteristic cycle involving a proliferative phase (first 8 to 12 months of life), quiescence, and a slow involution (beginning at about 12 months of age and involute at variable rates, typically over 5 to 8 years).
What is the distinguishing cellular marker for hemangioma?
What is the distinguishing cellular marker for hemangioma?
GLUT-1 (glucose transporter isoform-1) shares common antigenicity to placental tissue and GLUT-1 positivity distinguishes hemangiomas from vascular malformations. Exceptions are rapid involuting congenital hemangioma (RICH) and non-involuting congenital hemangiomas (NICH), which may be GLUT-1 negative.
What are the indications for treatment for hemangiomas of the head and neck?
What are the indications for treatment for hemangiomas of the head and neck?
Absolute indications for treatment include functional ocular obstruction or airway compromise. Other indications for intervention include large ulcerated lesions with hemorrhage or infection, those prone to functional compromise (ear/nose) or long-term cosmetic deformity, and those that are a source of psychosocial trauma to the child.
What is the first-line treatment for hemangiomas? What other treatments are available?
What is the first-line treatment for hemangiomas? What other treatments are available?
Currently, propranolol is used as the first-line treatment for hemangiomas unless a contraindication exists. Propranalol is a nonselective beta blocker that exerts a vasoconstrictive effect, which may result in reduction of lesion volume, softening, and regression of the lesion. Induction of apoptosis is also a possible mechanism of action for reducing hemangioma lesions. Propranolol has a 97% response rate and is taken orally with possible utility for topical beta blockers such as timolol. Side effects include bronchospasm, hypoglycemia, GERD, hypotension, and somnolence.
Systemic or intralesional steroids were the mainstay of therapy prior to the use of propranolol and exhibit a 50% to 90% response rate. Intralesional injections require multiple treatments at 6- to 8-week intervals. Periorbital lesions should not undergo intralesional injections because this carries a risk of central retinal artery occlusion.
Interferon a-2a is an angiostatic agent indicated if steroids or propranolol are ineffective or for recurrent or refractory cases. It is not commonly used secondary to a 25% risk of spastic diplegia.
Photocoagulation of hemangiomas can be performed with pulsed dye (superficial), argon (ulcerated or active bleedings), and Nd:Yag (deep penetration into dermis) lasers.
Surgical excision is typically timed during the involution phase or during the proliferative phase in cases recalcitrant to medical therapy.
What are the advantages and limitations of medical treatments for hemangiomas?
What are the advantages and limitations of medical treatments for hemangiomas?
See Table 54-1.
What is Kasabach-Merritt syndrome?
What is Kasabach-Merritt syndrome?
Kasabach-Merritt syndrome is a complication of rapidly enlarging vascular lesions (hemangioma) and is characterized by platelet trapping, hemolytic anemia, thrombocytopenia, and coagulopathy. This is most commonly associated with kaposiform hemangioendothelioma and tufted angioma.
What is PHACES syndrome?
What is PHACES syndrome?
PHACES is an acronym for Posterior fossa malformation, Hemangiomas, Arterial anomalies, Cardiac defects (coarctation of the aorta), Eye abnormalities (coloboma), and Sternal abnormalities or ventral developmental defect (need 2 of 6 for diagnosis). PHACES syndrome is common in patients with segmental (dermatome distribution) hemangioma. Workup should include ophthalmology and cardiology consultation along with brain MRI.
Hemangiomas in the beard distribution carry high risk of what related vascular anomaly? (Figure 54-1)
Hemangiomas in the beard distribution carry high risk of what related vascular anomaly? (Figure 54-1)
Hemangiomas in the V3/beard distribution have a high incidence (≈30% to 65%) of airway hemangioma, which may involve the oral cavity, oropharynx, hypopharynx, supraglottis, glottis, or subglottis. The subglottis is the most common location of focal hemangioma in the upper airway. Treatment modalities include systemic therapy with propranolol or steroids and local treatment with laser therapy or surgical excision. A tracheotomy may be required to bypass obstruction in some cases.
What is a port-wine stain?
What is a port-wine stain?
Port-wine stain is a superficial capillary vascular malformation typically present at birth appearing as a sharply demarcated pink-red patch that darkens over time and grows proportionately to the child. Pulsed-dye laser is the gold standard treatment with improved results if treated early in life.
What syndrome is related to the pictured vascular malformation?
What syndrome is related to this vascular malformation?
Sturge-Weber syndrome, also known as encephalotrigeminal angiomatosis, is characterized by a facial port-wine stain in the V1 (ophthalmic) distribution, glaucoma, seizures, mental retardation, and dural involvement.
Figure: Infant with port-wine stain (capillary vascular malformation) in V1/ophthalmic distribution associated with Sturge-Weber syndrome.
How are lymphatic malformations (LM) classified (based on 1996 International Society for the Study of Vascular Anomalies)? (Figure 54-3)
How are lymphatic malformations (LM) classified (based on 1996 International Society for the Study of Vascular Anomalies)? (Figure 54-3)
Classified as macrocystic (e.g., cystic hygroma), microcystic (e.g., lymphangioma), or mixed. Macrocystic LM are comprised of single or multiple cysts >2 cm3 in size. Microcystic LM are cysts <2 cm3. Mixed LM contain both macro- and microcystic components.
Figure: Child with left sided macrocytic lymphatic malformation
What are the mainstays of treatment for lymphatic malformations?
What are the mainstays of treatment for lymphatic malformations?
Microcystic lesions are more severe and extensively infiltrate tissues; treatment is usually not curative. Treatment goals are to correct deformity and maintain function via surgery, coblation/radiofrequency, or laser excision/reduction. Macrocystic lesions are amenable to treatment with complete surgical excision or sclerosing agents such as doxycycline, bleomycin, ethanol, and OK-432 (picibanil). Acutely infected cysts may be treated with antibiotics and/or steroids.
What is the diagnostic workup for lymphatic malformation? (Figure 54-4)
What is the diagnostic workup for lymphatic malformation?
MRI with gadolinium and fat suppression, which shows marked high intensity of the lesion on T2 images and fluid/fluid levels suggestive of LM. Ultrasound may be useful, but CT scans are often not helpful.
Figure: T2-weighted MRI scan of a microcystic lymphatic malformation demonstrating fluid layering.
Which low flow vascular malformation tends to involve muscle such as the tongue? (Figure 54-5)
Which low flow vascular malformation tends to involve muscle such as the tongue? (Figure 54-5)
Venous malformations tend to involve muscles and may be deep. These lesions tend to swell with activity or in a dependent fashion. They can be painful, may clot, and may have palpable phleboliths (can be identified on US or CT scan) from previous clot resolution.
Figure: Child with venous malformation affecting the tongue, floor of mouth, and lower lip.
