Hemangioma Infantil

01Pathophysiology

Infantile hemangioma (IH) is the most common benign vascular tumor of infancy, affecting approximately 4–5% of children. It arises from clonal hyperproliferation of endothelial cells and follows a predictable, triphasic natural history that distinguishes it from vascular malformations.

Proliferative phase begins at around 1–2 weeks of age and accelerates between 1–3 months, peaking at approximately 5 months. During this phase, clusters of unencapsulated capillaries form well-defined lobules separated by thin septa or normal soft tissue. These capillaries are lined by plump endothelial cells with enlarged nuclei and large cytoplasm, surrounded by pericytes without smooth muscle cells. The tumor also contains mast cells and interstitial dendritic cells. This rapid angiogenesis is what produces the characteristic bright red, raised, "strawberry-like" appearance of superficial lesions. The deeper component, when present, appears as a bluish or skin-colored subcutaneous mass because the proliferating vessels sit below the dermis.

Stabilization (plateau) phase follows from approximately months 6–9, where growth slows and the tumor size remains relatively constant.

Involution phase is the hallmark that separates IH from other vascular tumors. Beginning around age 1 year, it proceeds gradually through age 4–10 years. During involution, capillaries regress and are replaced by fibrofatty (adipose) tissue. There is increased mast cell activity and apoptosis of endothelial cells, with thickening and hyalinization of the basement membrane. This is why residual skin changes after involution often include telangiectasia, fibrofatty tissue, or atrophic scarring rather than a completely normal surface.

A critical concept for the exam: the proliferative phase is always faster than the involution phase. The tumor grows rapidly over weeks to months but takes years to involute. This asymmetry is why intervention is considered during proliferation for high-risk lesions, since waiting for natural involution may result in permanent functional or cosmetic damage.

At birth, the skin lesion is typically absent, but precursor signs may be present: a pale or blanched area, telangiectasia, or a grayish patch at the future tumor site.

The majority of lesions (60%) are located on the head and neck, with 25% on the trunk and 15% on the extremities. IH can also involve mucosal surfaces and extracutaneous organs, with the liver being the most commonly affected internal organ. Hepatic hemangiomas can be asymptomatic or, in severe cases, cause high-output congestive heart failure, consumptive hypothyroidism, or hepatic failure.

When IH is multifokal with more than 5 cutaneous lesions, screening with hepatic and abdominal USG is recommended to evaluate for visceral involvement.

IH is generally localized, but when large or segmental, it may be part of a syndromic association:

PHACE syndrome (Posterior fossa malformations, Hemangiomas of the face, Arterial anomalies, Cardiac anomalies, Eye abnormalities) is associated with large facial hemangiomas (>5 cm) on the head.

LUMBAR syndrome (Lower body infantile hemangioma, Urogenital anomalies, Ulceration, Myelopathy, Bony deformities, Anorectal malformations, Arterial anomalies, Renal anomalies) is associated with segmental hemangiomas of the lumbosacral, sacrococcygeal, or pelvic region.

02Classification & Clinical Manifestation

Classification by Tumor Depth

Classification by Distribution

Natural History Timeline

03Diagnostic Workup

The vast majority of IH cases are diagnosed clinically. A typical history of a lesion appearing at 1–2 weeks with rapid growth in the first few months of life, combined with the characteristic physical examination (bright red, soft, compressible, well-circumscribed), is sufficient for diagnosis.

USG Doppler is the best initial imaging modality when the clinical diagnosis is uncertain, when you need to evaluate the extent of a deep component, or when there is concern about visceral involvement. The hallmark finding is a well-defined solid mass with high-flow vascularity but without arteriovenous shunting. The absence of AV shunting is what differentiates IH from arteriovenous malformations on imaging.

Histopathology is rarely needed and is reserved for cases where the clinical presentation is atypical and there is concern for a malignant or borderline vascular tumor. During the proliferative phase, you see unencapsulated lobules of capillaries with plump endothelial cells. During the involution phase, capillary regression with replacement by adipose tissue, increased mast cells, apoptosis, and basement membrane thickening with hyalinization are seen. The immunohistochemical marker GLUT1 is the key discriminator: IH is GLUT1 positive, while congenital hemangiomas (both RICH and NICH) are GLUT1 negative.

MRI/MRA is not routine but becomes necessary when syndromic association is suspected. For PHACE syndrome, MRI of the brain and MRA of the head and neck vasculature are indicated. For LUMBAR syndrome, spinal MRI is warranted.

When IH is multifocal or large, thyroid function screening (T3, TSH) should be performed because the tumor tissue can express type 3 iodothyronine deiodinase, which inactivates circulating thyroid hormones, leading to consumptive hypothyroidism.

Multidisciplinary referral to cardiology, ophthalmology, and neurology is recommended for syndrome-associated IH.

04Management & Treatment

The first and most important clinical decision is whether the IH requires treatment at all. Most IH will involute spontaneously without clinically meaningful residua, so observation with close follow-up is appropriate for lesions that are small, superficial, located away from vital organs, and uncomplicated (1B).

Indications for active treatment include: life-threatening complications (airway obstruction), functional impairment (periorbital IH causing amblyopia, nasal IH causing feeding difficulty), ulceration, syndromic association (PHACE/LUMBAR), and IH involving anatomically sensitive areas such as the eyes, nose, mouth, genitalia, perianal region, or any location with high risk of permanent disfigurement or bleeding.

Topical therapy with timolol maleate 0.5% (a beta-blocker) is indicated for small, superficial, thin IH. The dose is 1–2 drops applied topically twice daily for 6–9 months, extendable to 12 months or longer depending on tumor size. In Indonesia, the available formulation is timolol ophthalmic solution 0.5% (timolol gel is not currently available). Timolol reduces volume and redness in superficial-type IH. This is useful to remember: topical timolol is for superficial, small lesions only. It will not adequately treat deep or large IH.

Oral propranolol is the gold standard systemic therapy (1A) for high-risk IH. The starting dose is 1 mg/kg/day, titrated to an optimal dose of 2–3 mg/kg/day divided into 2–3 doses. Treatment duration is typically 6 months and may continue up to age 12 months. Propranolol at 3 mg/kg/day during the proliferative phase for 6 months has been shown to be both safe and effective (1A). Before initiating propranolol, the clinician should assess for contraindications: reactive airway disease (asthma/bronchospasm), sinus bradycardia, heart block, decompensated heart failure, and hypoglycemia risk (especially in premature or low-birth-weight infants who are fasting). Monitoring of heart rate and blood pressure is recommended during dose initiation and titration. The mechanism of propranolol in IH involves vasoconstriction (immediate effect causing visible color change), inhibition of angiogenesis (via downregulation of VEGF and bFGF), and induction of apoptosis of endothelial cells.

Oral corticosteroids (prednisolone or prednisone at 2–5 mg/kg/day in 3 divided doses for 4–12 weeks, followed by a gradual taper through age 9–12 months) are the second-line systemic option (1B), reserved for patients with contraindications to propranolol or inadequate response to propranolol.

Interferon-alpha (1C) is reserved for steroid-resistant IH that threatens vital organ function or life. Vincristine and cyclophosphamide (both 1C) represent last-resort chemotherapy options for refractory cases.

Surgical indications (1C) include: ulcerated IH in areas prone to complications (anogenital, axillary, neck), airway obstruction, IH at functionally important anatomic sites (nose, eyes, ears), residual tissue (permanent scarring, fibrofatty remnants) after involution, pedunculated IH, failure of systemic and topical therapy, and cases where surgical excision can close the defect easily. Surgery is not recommended as first-line during the proliferative phase.

Laser therapy with pulse dye laser (1B) is indicated for recurrent IH, residual lesions, and patients with pharmacologic contraindications. PDL is beneficial for post-involution skin changes such as residual redness and telangiectasia. Laser can be combined with systemic or topical therapy and reportedly enhances efficacy without added side effects. However, PDL is not effective for early proliferating lesions and has been associated with skin atrophy and hypopigmentation. Long-pulsed Nd:YAG 1064 nm laser (3B) is an alternative for deeper components.

Intralesional corticosteroid injection (1B) is recommended for focal, large IH during the proliferative phase or for anatomically sensitive locations such as the lip.

Multidisciplinary referral (1B) to cardiology, ophthalmology, and neurology is indicated for syndrome-associated IH (PHACE, LUMBAR).

05Differential Diagnosis & Distractors

06Traps & High-Yield Pearls

The single most common trap with infantile hemangioma is confusing it with congenital hemangioma or vascular malformations. The test-writer will build a vignette around the timeline: if the lesion is fully present at birth and not growing, it is not IH. IH appears at 1–2 weeks and then proliferates. A vignette describing a "red birthmark present since day one that has not changed in size" points away from IH and toward a capillary malformation or congenital hemangioma. The key discriminator on pathology is GLUT1: positive for IH, negative for congenital hemangioma.

The second trap is management sequencing. Students often default to "surgery" or "laser" when they see a growing vascular tumor in an infant. The correct first-line systemic therapy for high-risk IH is oral propranolol, not corticosteroids and not surgery. Corticosteroids are second-line, reserved for propranolol failure or contraindications. Surgery is not first-line during the proliferative phase. A vignette where a 3-month-old has a rapidly growing periorbital hemangioma causing visual obstruction is testing whether you choose propranolol (correct) over steroids or surgery (incorrect first step).

The third commonly tested concept is screening for visceral involvement. When a vignette describes an infant with more than 5 cutaneous hemangiomas (multifocal IH), the next best step is abdominal/hepatic USG to screen for hepatic hemangioma, plus thyroid function tests (T3, TSH) to screen for consumptive hypothyroidism.

The fourth trap involves syndromic associations. A large, segmental facial hemangioma (>5 cm on the head) should trigger evaluation for PHACE syndrome with MRI/MRA and echocardiography. A lumbosacral segmental hemangioma should prompt consideration of LUMBAR syndrome with spinal MRI. Students who treat the hemangioma without investigating for syndromic features will miss the question.

Finally, remember that USG Doppler shows high-flow vascularity without AV shunting in IH. A vignette describing a high-flow lesion with AV shunting points toward an arteriovenous malformation, not IH. This imaging distinction is a favorite distractor on the exam.

The core competency being tested: recognizing the natural history timeline of IH (not present at birth, proliferates, then involutes), selecting propranolol as first-line systemic therapy, knowing when to screen for complications (multifocal = hepatic USG + thyroid), and distinguishing IH from congenital hemangioma using GLUT1 status.