Tufted angioma or Angioblastoma
(Nakagawa) is a rare, benign, vascular tumor, characterized histologically by tufts of capillary-sized vessels in the dermis.
This acquired lesion is closely related to capillary hemangioma.
Angioblastoma was reported in
the Japanese literature in 1929. In 1989 this lesion was described
as Acquired tufted angioma.
Age:
Young adults and children.
Site:
Usually located on the neck, the shoulders and the upper trunk and
sometimes on the lower limbs. A case of perianal tufted angioma
mimicking an anal fissure has also been reported.
Clinical presentation:
The lesions
developed as solitary or
multiple tender, erythematous, macules, papules
or plaques.
Microscopic features:
Microscopically, there
are multiple irregularly distributed vascular tufts and lobules within the dermis and subcutis
(cannon ball pattern).
The lobules are composed
of endothelial cells with small round to ovoid nuclei, surrounded by pericytes.
Dilated cresent-shaped thin walled vascular channels are noted
at the periphery. This is probably caused by bulging of the lobules into
the dilated vessels giving it a cresentic shape.
The vascular
element may be accompanied by hyperplasia of eccrine sweat glands.
Inflammation and oedema
are not seen. There may be some hemosiderin pigment deposition.
There is no cytological
atypia. Some mitotic figures may be present..
Immunohistochemistry:
The tumour cells
are positive for CD34, CD31 smooth muscle actin, muscle specific
antigen, and vimentin. The lesions are negative for keratins and
factor XIIIa.
Differential diagnosis :
Kaposi's sarcoma :
interlacing bundles of spindle cells and slit like vessels.
Low-grade angiosarcoma;
Kaposi hemangioendothelioma;
Bacillary angiomatosis;
Pyogenic granuloma
;
Glomeruloid hemangioma
;
Masson's tumour;
Spindle cell hemangioendothelioma
;
Reactive
angioendotheliomatosis
:
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