Definition/General
Introduction:
Hemangioma is a benign vascular tumor
It represents proliferation of endothelial cells
Most common benign soft tissue tumor in infants
FNAC shows endothelial cells and blood.
Origin:
Arises from vascular endothelium
Can be congenital or acquired
Infantile hemangioma: Proliferative phase
Adult hemangioma: Stable lesions
Originates from primitive mesenchymal cells.
Classification:
WHO classification: Benign vascular tumor
Types: Capillary hemangioma
Cavernous hemangioma
Mixed type
Intramuscular hemangioma
Synovial hemangioma.
Epidemiology:
Most common in infancy (10% of infants)
Female predominance (3-5:1)
Head and neck most common site
Premature infants higher risk
Low birth weight association.
Clinical Features
Presentation:
Soft, compressible mass
Bluish discoloration
Temperature elevation (proliferative)
Pulsatile (some cases)
Rapid growth (infantile)
Well-demarcated borders.
Symptoms:
Usually painless
Cosmetic concern
Ulceration (large lesions)
Bleeding (trauma/ulceration)
Mass effect
Functional impairment (location-dependent).
Risk Factors:
Female gender
Premature birth
Low birth weight
Advanced maternal age
Multiple gestation
Placental anomalies.
Screening:
Clinical examination
Doppler ultrasound
MRI for extent
FNAC if diagnosis unclear
Ophthalmologic evaluation (periocular)
Airway assessment (large lesions).
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Gross Description
Appearance:
Soft, spongy mass
Red to purple color
Compressible consistency
Well-circumscribed
Lobulated surface
Hemorrhagic on cut section.
Characteristics:
Vascular spaces visible
Soft consistency
Purple-red appearance
Bleeding tendency
Cystic spaces (cavernous type)
Heterogeneous texture.
Size Location:
Head and neck (60%)
Trunk (25%)
Extremities (15%)
Size: Variable 0.5-15 cm
Superficial more common
Deep lesions (intramuscular).
Multifocality:
Usually solitary
Multiple lesions (5% cases)
Segmental distribution
PHACES syndrome association
Hepatic hemangiomas (multiple cutaneous).
Microscopic Description
Histological Features:
FNAC shows endothelial cells in clusters
Bland nuclear features
Abundant blood
Capillary-like structures
No cellular atypia
Background of RBCs.
Cellular Characteristics:
Plump endothelial cells
Oval nuclei
Fine chromatin
Small nucleoli
Moderate cytoplasm
Well-defined cell borders.
Architectural Patterns:
Cohesive cell clusters
Capillary-like arrangements
Hemorrhagic background
Individual endothelial cells
Vascular fragments
Clean background (when not traumatic).
Grading Criteria:
Benign features
No grading applicable
Assessment: Endothelial morphology
Absence of atypia
Vascular pattern
Background characteristics.
Immunohistochemistry
Positive Markers:
CD31 - positive (endothelial)
CD34 - positive (endothelial)
Factor VIII - positive
ERG - positive (nuclear)
FLI1 - positive (nuclear)
GLUT1 - positive (infantile).
Negative Markers:
Cytokeratin - negative
EMA - negative
S-100 - negative
Desmin - negative
Smooth muscle actin - negative (endothelium)
D2-40 - negative (blood vascular).
Diagnostic Utility:
Endothelial markers confirm vascular nature
GLUT1 distinguishes infantile hemangioma
D2-40 negative (vs lymphatic malformation)
Ki-67 variable (phase-dependent)
Differentiation from other vascular lesions.
Molecular Subtypes:
Infantile hemangioma: GLUT1+, CD31+, CD34+
Congenital hemangioma: GLUT1-, CD31+, CD34+
All types: Endothelial markers positive
Cavernous: Same markers, larger vessels.
Molecular/Genetic
Genetic Mutations:
VEGFR2 pathway activation
Endothelial progenitor cell involvement
Simple karyotype
Clonal proliferation in some cases
No specific mutations identified.
Molecular Markers:
VEGF pathway activation
Angiogenic factors upregulated
Endothelial proliferation markers
Low mutational burden
Normal tumor suppressors
Proliferative phase: High VEGF.
Prognostic Significance:
Excellent prognosis
Spontaneous involution (infantile type)
No malignant potential
Complete resolution by age 5-7 years (infantile)
Stable lesions in adults.
Therapeutic Targets:
Observation (most cases)
Propranolol (proliferative infantile)
Corticosteroids (severe cases)
Laser therapy (superficial)
Surgical excision (complications)
Interferon-α (refractory).
Differential Diagnosis
Similar Entities:
Angiosarcoma
Hemangioendothelioma
Vascular malformation
Pyogenic granuloma
Kaposi sarcoma
Lymphatic malformation.
Distinguishing Features:
Hemangioma: Benign endothelium, GLUT1+ (infantile), no atypia
Angiosarcoma: Atypical endothelium, infiltrative, high Ki-67
Vascular malformation: Mature vessels, GLUT1-
Pyogenic granuloma: Lobular capillaries, surface ulceration
Kaposi: Spindle cells, HHV8+
Lymphatic: D2-40+.
Diagnostic Challenges:
Distinguishing from vascular malformations
Angiosarcoma in older patients
Traumatic sampling artifacts
Phase of hemangioma (proliferative vs involuting)
Deep location imaging correlation.
Rare Variants:
Epithelioid hemangioma
Spindle cell hemangioma
Targetoid hemosiderotic hemangioma
Microvenular hemangioma
Anastomosing hemangioma.
Sample Pathology Report
Template Format
Sample Pathology Report
Complete Report: This is an example of how the final pathology report should be structured for this condition.
Specimen Information
Fine needle aspiration from [site], [size] cm vascular lesion
Clinical History
[age]/[sex] with [duration] history of soft, compressible, [color] mass at [site]
Microscopic Examination
Smears show cohesive clusters of bland endothelial cells with oval nuclei and moderate cytoplasm. Background shows abundant blood and capillary-like structures. No cellular atypia noted.
Immunocytochemistry
CD31: Positive, CD34: Positive, GLUT1: [result], D2-40: Negative
Cytological Diagnosis
Cytological features consistent with HEMANGIOMA
Comments
Benign vascular tumor. Clinical correlation and imaging recommended. Excellent prognosis. Consider observation vs treatment based on clinical factors.