S8C27P13-1:The vascular changes in the upper portion of the dermis (red arrows) are most characteristic of acral angiodermatitis; they are in keeping with a response to the altered hemodynamics associated with stasis. Angiodermatitis is a vaso-proliferative process manifested in the formation of new vessels in lobular arrays. These prolferative changes usually are most pronounced in the upper portion of the dermis but, in severe examples, may be represented at all levels of the dermis. In this example, there is a prominent increase in the number of vessels in the lower portion of the dermis; some of the abnormal vessels are muscular veins. In this particular example, the fibrosing reaction has probably extended into the subcutaneous fat, expanding the domain of the “dermis.”

S8C27P13-2: At a higher magnification, the lobular aggregates (red arrows) of newly formed vessels are prominent in the papillary dermis; they extend into the reticular dermis. It is a characteristic of acral angiodermatitis that the most prominent changes are to be found in the papillary dermis and the upper portion of the reticular dermis. The vessels, in this example, are supported by a myxoid matrix that is relatively free of inflammation. The lack of inflammation is in keeping with pure angiodermatitis, as opposed to angiodermatitis as an associated finding in a dermatitis, such as a neurodermatitis.

S8C27P13-3: The margin of a stasis ulcer is represented. At the margin, an overhanging lip is covered by squamous epithelium. The prominent component of angiodermatitis (red arrows) is a marker of the role for stasis in the formation of the ulcer (providing there are no specific markers for some other disorder which might be complicated by stasis changes). The ulcer is covered by fibrin.