Infantile Hemangioma

 Slightly dilated and irregular in shape


image Lined by single layer of bland endothelial cells


• Secondary involutional changes in central portion

• Peripheral cellular areas show proliferation of vascular channels in loose fibrous stroma




Ancillary Tests




• Positive for vascular markers: Factor VIII, CD31, CD34, FLI-1

• GLUT-1 is often positive, while most vascular malformations are negative


Top Differential Diagnoses




• Angiosarcoma
image Previously termed infantile hemangioendothelioma type 2

image Key distinguishing feature is nuclear atypia of endothelial cells

• Cavernous hemangioma

• Lymphangioma

• Mesenchymal hamartoma

• Vascular malformation

image
Poorly Circumscribed Mass
This partial hepatectomy specimen shows a poorly circumscribed, white-tan mass image with central calcification. Infantile hemangioma may present as a solitary or multifocal lesion.


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Cellular Peripheral Portion
The peripheral, highly cellular portion of an infantile hemangioma image shows an irregular interface with the hepatic parenchyma and is partially entrapping it image .

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Closely Packed Vessels
A closer view of the cellular peripheral portion of the tumor shows densely packed vascular channels lined by a single layer of plump endothelial cells without significant cytologic atypia.

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CD34 Immunohistochemistry
The endothelial cells lining the irregular, variably dilated, capillary-like vascular channels are immunoreactive for the endothelial marker CD34.


TERMINOLOGY


Synonyms




• Originally described by Dehner and Ishak as infantile hemangioendothelioma type 1


Definitions




• Hepatic vascular neoplasm
image Most common hepatic neoplasm during 1st year of life

image Accounts for 15% of primary liver tumors in pediatric population


CLINICAL ISSUES


Epidemiology




• Age
image Most present before age of 6 months

image Rare in adults

Apr 20, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Infantile Hemangioma

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