perithelial

It is predominantly perithelial, rather than an endothelial tumour.

ACD was initially considered to be synonymous with Fabry's disease, first described by Anderson and Fabry independently in 1898.9 It is a rare X-linked recessive disorder, with an incidence of about 1:40 000,10 caused by the mutation in a-galactosidase, a gene on long arm of X chromosome11 and subsequent deficiency of lysosomal hydrolase, alpha-galactosidase, which results in the progressive deposition of uncleaved neutral glycosphingolipids, predominantly a-galactosyl-lactosyl ceramide (trihexosyl ceramide) within the lysosomes of endothelial, perithelial, smooth muscle cells, autonomic nervous system, kidneys, eyes and heart.12

Immuno histochemistry shows actin as a perithelial component (11) among the tumor capillaries, also there was positivity for VwF usually limited to a few vessels.