Pathology of Acquired Tufted Angioma or Angioblastoma [Nakagawa]
Tufted angioma or Angioblastoma (Nakagawa) is a rare, benign, vascular tumour, 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.
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.
The lesions developed as solitary or multiple tender, erythematous, macules, papules or plaques.
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..
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 :
interlacing bundles of spindle cells and slit like vessels.