Diffuse dermal angiomatosis (DDA) is a rare acquired, cutaneous, reactive, vascular disorder that was originally thought to be a variant of cutaneous reactive angiomatosis (CREA) but is now considered to be on the spectrum of CREA. This article will focus on DDA and review the literature of prior case reports with brief descriptions of the differential diagnosis.
Case Report
A 43-year-old Haitian man presented to the clinic with a lesion on the left buttock that had developed over the last 6 years. The patient stated the lesion had been enlarging over the last several months. Upon examination, there was a large (15-cm diameter), indurated, hyperpigmented plaque covering the left buttock (Figure 1). The patient reported no medical or contributory family history. Upon review of systems, he described a burning sensation sometimes in the area of the lesion that would develop randomly throughout the year.
Figure 1. A 15-cm, indurated, hyperpigmented plaque covering the left buttock. A, Posterior view. B, Lateral view.
Three biopsies were performed, which revealed a collection of slightly dilated blood vessels with normal-appearing endothelial cells occupying the mid dermis and deep dermis (Figure 2). Immunohistochemical stains with antibodies were directed against human herpesvirus 8 (HHV-8), CD31, CD34, the cell surface glycoprotein podoplanin, Ki-67, and smooth muscle actin antigens, with appropriate controls. The vessel walls were positive for CD31, CD34, and smooth muscle actin, and negative for HHV-8 and podoplanin; Ki-67 was not increased. These histologic findings were consistent with a diagnosis of DDA. A detailed history was taken. The cause of DDA in our patient was uncertain.
Figure 2. A, Biopsy of the patient’s left buttock showed a diffuse interstitial proliferation of vascular structures and dilated lumen in the papillaryand reticular dermis (H&E, original magnification ×4). B and C, Higher magnification showed well-differentiated endothelial cells forming small vascular structures with intraluminal erythrocytes (H&E, original magnifications ×20 and ×40).
Comment
Classification and Epidemiology
Diffuse dermal angiomatosis is a rare acquired, cutaneous, reactive, vascular disorder first described by Krell et al1 in 1994. Diffuse dermal angiomatosis is benign and is classified in the group of cutaneous reactive angiomatoses,2 which are benign vascular disorders marked by intravascular and extravascular hyperplasia of endothelial cells that may or may not include pericytes.2 Diffuse dermal angiomatosis was originally described as a variant of CREA, which is characterized by hyperplasia of endothelial dermal cells and intravascular proliferation.3 However, DDA has more recently been identified as a distinct disorder on the spectrum of CREA rather than as a variant of CREA.2 Given the recent reclassification, not all physicians make this distinction. However, as more case reports of DDA are published, physicians continue to support this change.4 Nevertheless, DDA has been an established disorder since 1994.1