In angiectasis, preexisting clitoral gland blood vessels become dilated and filled with blood cells, accompanied by compression of the clitoral gland parenchyma (Figure 1 and Figure 2). A distinction between angiectasis and hemangioma should be attempted, although the distinction is not always obvious. Hemangiomas tend to be well-circumscribed, unencapsulated masses composed of tightly packed, dilated vascular spaces. Each vascular space is enclosed and lined by a single layer of normal-appearing endothelial cells aligned on collagenous septa, which are usually thin, although some have broad collagenous stroma. Angiectasis does not usually present as a well-circumscribed mass: the dilated vascular channels often course irregularly through the tissue. Compression of adjacent parenchyma may occur in both angiectasis and hemangioma.
National Toxicology Program. 2003. NTP TR-509. Toxicology and Carcinogenesis Studies of 2,4-Hexadienal (89% trans,trans Isomer, CAS No. 142-83-6; 11% cis,trans Isomer) in F344/N Rats and B6C3F1 Mice (Gavage Studies). NTP, Research Triangle Park, NC.Abstract: https://ntp.niehs.nih.gov/go/14896