Make the Diagnosis

Violaceous papules on calf & foot

A 70-year-old male with a history of a left lower-extremity deep vein thrombosis and right cerebrovascular accident resulting in left hemiplegia presented with progressively worsening violaceous papules on his left foot and calf. The lesions improved when his leg was elevated and became more prominent when his leg was in a dependent position. He also has a history of venous insufficiency in his left lower extremity.

Make the diagnosis:

Kaposi sarcoma

Acroangiodermatitis of Mali

Arteriovenous malformation

Hemangioma

Acroangiodermatitis of Mali, also called pseudo–Kaposi sarcoma, is an uncommon, benign condition that usually presents on the distal lower extremities or feet as red to violaceous papules, patches, and plaques.

Clinically, lesions may look similar to Kaposi sarcoma (KS). It is considered to be a variant of stasis dermatitis or severe chronic venous stasis with a more exuberant vascular proliferation of preexisting vasculature. Although the exact etiology is unknown, it is thought that chronic edema, increased venous pressure, and tissue hypoxia may induce fibroblast and vascular proliferation.

It has also been described in association with vascular anomalies, such as Klippel-Trenaunay syndrome, Stewart-Bluefarb syndrome, and Prader-Labhart-Willi syndrome, and is caused by arteriovenous fistulae. Paralysis of lower extremities and amputation stumps are predisposing factors.

KS has four clinical variants: classic KS, African endemic KS, KS in immunocompromised patients, and AIDS-related epidemic KS. All types are caused by the human herpesvirus-8 (HHV-8). Violaceous lesions generally begin as macules and may progress to nodules or tumors.

Punch biopsies were performed in our patient. Histologically, thin-walled, dilated, capillary-like structures were present with a thin layer of surrounding pericytes with reactive fibrosis, hemorrhage, hemosiderin, and a scant chronic inflammatory cell infiltrate. The endothelial cells did not show atypia or mitotic activity. Endothelial cells were positive for CD31, CD34, and CD99. Pericytes and some of the endothelial cells were positive for actin and negative for D2-40, desmin, and HHV-8. In KS, vessels appear like slitlike or jagged spaces lined by spindled endothelial cells. Mild cytologic atypia is usually present. Endothelial cells are characteristically plump. A distinguishing feature in KS is the “promontory sign,” in which new vessels protrude into the vascular space. CD34 is usually negative and HHV-8 is positive.

Dr. Donna Bilu Martin, a dermatologist in private practice in Aventura, Fla.

Dr. Donna Bilu Martin

Acroangiodermatitis of Mali may improve when the underlying venous insufficiency is addressed with compression stockings, pumps, or vascular intervention. Laser ablation of individual lesions has been described in the literature. Dapsone, oral erythromycin, and topical corticosteroids have been reported as helpful in some patients.

This case and these photos were submitted by Dr. Bilu Martin.

Dr. Bilu Martin is a board-certified dermatologist in private practice at Premier Dermatology, MD, in Aventura, Fla. More diagnostic cases are available at mdedge.com/dermatology. To submit a case for possible publication, send an email to [email protected].

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