Orbital Vascular Hamartomas PDF

Vascular hamartomas: abnormal proportion of vascular elements present at a cutaneous site - Growth on tissues that are supposed to be there Capillary hemangioma: The benign, high-flow hamartomatous proliferation of primitive vasoformative tissues AKA strawberry hemangioma ○ Ju...

Vascular hamartomas: abnormal proportion of vascular elements present at a cutaneous site - Growth on tissues that are supposed to be there Capillary hemangioma: The benign, high-flow hamartomatous proliferation of primitive vasoformative tissues AKA strawberry hemangioma ○ Just composed of a mass of small blood vessels Typically appears as a raised, red or purplish lesion on the skin, particularly on the face, scalp, or neck Most common orbital benign vascular tumor of childhood (1% to 2% of infants) Female 3:2 Predisposing factors: maternal chorionic villus sampling and prematurity ○ Chorionic villus sampling (or CVS) is a prenatal test that diagnoses DNA genetic conditions in a fetus by looking at cell samples from the placenta (done around 10-12 weeks of pregnancy) One-third are noted at birth (virtually all are diagnosed by age 6 months) Largest size within 6 months and then typically involutes* Most commonly a unilateral diffuse subcutaneous or circumscribed, dimpled, red dermal lesion (strawberry nevus) is noted on the upper eyelid Palpebral or forniceal conjunctiva may be involved Commonly is associated with orbital septum (variable degrees of proptosis if it extends more posteriorly) Early flat, then bulky, compressible masses in weeks to months Most common ocular complications of adnexal capillary hemangiomas is visual loss, most often resulting from amblyopia or in rare cases optic atrophy Amblyopia occurs in 44% to 64% of these infants (anisometropia, visual deprivation, or both) ○ Amblyopia that can be caused by strabismus or sensorial deprivation because of anisometropia Anisometropia may result from axial myopia induced by the eyelid closure or astigmatism (plus cylinder axis points toward the tumor mass) Strabismus may be present in up to 34% of patients with periorbital infantile capillary hemangioma Associated visceral hemangiomas throughout the body have been reported; w/ time run other imaging tests to R/O other hemangiomas elsewhere ○ Laryngeal hemangiomas are the most frequent visceral vascular manifestation  ○ Sequestration of platelets and red blood cells leading to thrombocytopenia and bleeding diathesis (Kasabach-Merritt syndrome) can occur with large visceral lesions but are rare with isolated head and neck lesions a rare, life-threatening condition that occurs when a vascular tumor destroys platelets Diagnosis: normally not CT because too much radiation on a kid ○ Can be diagnosed readily by clinical inspection ○ Enhanced MRI (Gadolinium- pentetic acid enhancement, and fat suppression) if delineation of orbital involvement is required, or to confirm ○ High vascular flow may be demonstrated on Doppler echography ○ Histopathology ○ DDX ○ Rhabdomyosarcoma ○ Dermoid cyst in the area of the orbit and limbal area Composed of tissue that is not supposed to be there causing it ○ Orbital cellulitis Management considerations ○ Outlining the natural history of these lesions to the parents (justifying conservative management) ○ Rate of complete resolution w/ tx is 32% to 60% at 4 years of age, and 72% to 76% at 7 y/o ○ There is variable improvement in the remaining children until the age of 10 to 12 years Indications for treatment ○ Amblyopia (threatened occlusion of the visual axis) ○ Compression of the ON ○ Corneal exposure secondary to severe proptosis  If you ptosis, you have exposure ○ Induced astigmatism and anisometropic refractive error ○ Nonvisual indications Deep lesions that bleed frequently Secondary maceration and erosion of the epidermis Severe disfigurement Cardiovascular, hematologic, or obstructive complications Treatment ○ Intralesional injections of long and short-acting corticosteroids Long-acting steroid is directed deep into the lesion to prevent deposits from being visible under the skin Short-acting corticosteroid is given subcutaneously around the periphery of the capillary hemangioma Therapeutic effectiveness results from arteriolar constriction and narrowing of precapillary sphincters Separate 1- to 3-mL syringes with 25- or 27-gauge needles of : ○ ✓ 40 mg triamcinolone acetate and 6 mg betamethasone or ○ ✓ 40 mg methylprednisolone and 4 mg dexamethasone sodium phosphate Involution may begin in several days; usually is considerable within 2 to 4 wks May be repeated at 6-week intervals, as needed Cavernous hemangioma Benign, non infiltrative, low-flow hamartomas Vascular malformation (not a malformation) with large blood-filled pockets They do not contain tissue of the organ in which they are situated Often cited as the most common primary orbital tumor of adults Clinical Features ○ Typically in the fourth and fifth decades (although the age range < 18 - > 78) ○ 60% to 70% female preference ○ Gradually increasing painless proptosis common ○ Less common - orbital pain, eyelid swelling, diplopia, and gaze-induced amaurosis Usually isolated lesions  Very rarely, associated with multiple hemangiomas ○ involving predominantly the arms and trunk (usually evident at birth) ○ visceral lesions commonly in the small intestine leading to gastrointestinal bleeding and iron deficiency anemia Contrast-enhanced axial CT scan - well-demarcated, oval intraconal mass (normally at the lateral part of the middle third of the orbit) ○ Not an issue to do CT here ○ Axial magnetic resonance imaging - well-defined, homogeneous intraconal mass ○ T1-weighted image (A) ○ T2-weighted image (B) ○ Displacement of the optic nerve and indented posterior globe ○ Histopathology ○ Large, endothelium-lines, blood-filled spaces separated by fibrous septa ○ DDX: ○ Neurofibroma, cystic schwannoma, fibrous histiocytoma, vascular leiomyoma ○ All can have identical clinical, CT, and MRI findings Management consideration ○ As the natural history of cavernous hemangiomas is to enlarge- gets bigger ○ Excision is predominantly advised as soon as the diagnosis is established  Treatment ○ Surgical excision of the lesion ○ Blunt dissection reveals a nodular, plum-colored, encapsulated mass with vascular channels on its surface ○ Because of its low-flow character: punctured during surgery, leading to exsanguination and shrinkage of the tumor – facilitates excision ○ A cryo-probing may assist with extraction ○ No evidence of recurrence from incompletely excised lesions ○ Risks of surgery depend on location – at the orbital apex can be challenging ○ Transcranial approach (superomedial orbital apex) makes an incision in scalp and go through bone to reach orbital apex vs transorbital (apical locations) makes incision in eyelid and goes directly through orbit