Pathology of Kaposiform  Hemangioendothelioma         

Dr Sampurna Roy MD                              2022

This lesion is commonly associated with Kasabach-Merritt syndrome and lymphangiomatosis.  

Site: Retroperitoneum, subcutaneous or deep soft tissue of upper extremities, head and neck area. 

Age: Occurs as solitary tumour in infants (first decade of life) .

Microscopic features:

Tumour consists of infiltrating lobulated nodules of spindle shaped endothelial cells

Nodules are separated by thick fibrous bands ; 

Spindle cells form short fascicles and line slit-like and round vessels ; 

Minimal cytological  atypia ; 

Mitotic activity is low  ; 

Epithelioid cells are sometimes  present ;

Cells  may contain hemosiderin pigment, hyaline globules and cytoplasmic vacuoles;

Ectatic vessels are present in the periphery ; 

Scattered microthrombi may be present within vascular spaces.

Immunohistochemistry: 

The spindle cells stain positively for CD34 and focally for CD31.

The pericytes around the capillaries stain positively for smooth muscle actin.  

Vascular Endothelial Growth Factor Receptor-3 (VEGFR-3): A Marker of Vascular Tumors with Presumed Lymphatic Differentiation, Including Kaposi's Sarcoma, Kaposiform and Dabska-Type Hemangioendotheliomas, and a Subset of Angiosarcomas.

Differential diagnosis :   

Kaposi's sarcoma (rare in children; multicentric; prominent chronic inflammatory infiltrate; lobular architecture is absent; dense fibrous bands are not present); infantile hemangioma ;  acquired tufted hemangioma ; spindle cell hemangioendothelioma ;  

Angiosarcoma (endothelial atypia, increased mitotic activity and dermal collagen dissection by infiltrating tumour)

Dermatopathology Quiz Case 99

Kaposiform hemangioendothelioma: five patients with cutaneous lesion and long follow-up.

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Variable response to propranolol treatment of kaposiform hemangioendothelioma, tufted angioma, and Kasabach-Merritt phenomenon.

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Kaposi-like infantile hemangioendothelioma. A distinctive vascular neoplasm of the retroperitoneum.