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Malignant endovascular
papillary angioendothelioma, a rare but distinctive vascular tumour of
childhood, was first described in 1969 by Maria Dabska.
Malignant endovascular
papillary angioendothelioma of the skin in childhood.
Clinicopathologic study of 6 cases.
Cancer. 1969;24(3):503-10.
It
was termed malignant because of its mitotic activity, areas of necrosis,
and demonstrated ability to metastasize to regional lymph nodes.
Based on its good
long-term prognosis and variable histologic features, this lesion is
better classified as a borderline vascular tumour.
According to some authors Endovascular papillary angioendothelioma may not
be a distinct entity and may well include a heterogeneous group of
lesions.
Age:
Mostly occurs in
infants and children. Cases have also been reported in adults.
Site:
Slow growing pink or
bluish-black nodule located in the skin or soft tissue . There is slight
predominance in the head and neck region and extremities.
Microscopic features:
Image
Link: click (dermpath.de)
Presence of anastomosing
vascular channels.
Prominent endothelial
intraluminal papillary tufts with hyaline cores surrounded by lymphocytes.
The vascular spaces are lined ny monomorphic hobnail endothelial cells.
In some areas
glomeruloid structures are identified.
[
The three cell types originally described are as follows: i)
Lymphocyte-like cells ii) Large atypical cells sometimes showing hobnail
appearance iii) Flat endothelial cells ]
Papillary endothelial
proliferation with a central hyaline core is one of the most
characteristic features ,however, this type of
proliferation has been observed in other vascular tumours, such as angiosarcoma, retiform hemangioendothelioma and glomeruloid hemangioma.
Immunohistochemistry: Tumour cells
are positive for vimentin, von Willebrand factor,
CD31, and focally for CD34 and are negative for keratins, epithelial
membrane antigen, S-100 protein, and desmin.
Differential diagnosis:
Retiform hemangioendothelioma ;
Hobnail hemangioma;
Glomeruloid hemangioma; Intravascular
papillary endothelial hyperplasia (Masson's tumour) ;
Reactive
angioendotheliomatosis;
Angiosarcoma,
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