Acquired progressive lymphangioma (APL) or benign lymphangioendothelioma is a rare vascular lesion that occurs mainly in middle-aged or older adult patients (median age, 52 years; range 5-90 years) with no sex predilection. Cutaneous sites include lower limb, especially the thigh, upper limb, trunk, including breast, abdominal wall, back, intertriginous areas, head and neck region and shoulder. In most patients, the lesion presents as an asymptomatic, most often solitary, well-circumscribed, slowly enlarging, reddish or bruiselike, sometimes, pigmented, patch or plaque on which small erythematous papules may arise. APL may be associated with local pain, swelling or pruritus. The lesion may grow for several years. At the time of examination, it may be quite large (median size, 4cm; range 0.3-30cm).The clinical differential diagnosis includes hemangioma, Kaposi’s sarcoma, morphea and lichen planus. Complete excision is the treatment of choice for small lesions. Recurrence is rare and prognosis is excellent. Alternative treatments such as systemic corticosteroid administration have been shown to induce partial regression in isolated cases. Rarely, the lesion may regress spontaneously.
The epidermis is acanthotic and papillomatous. Jagged, irregularly shaped vascular channels dissect between dermal collagen bundles with full-thickness dermal involvement. The vascular spaces are more dilated in the superficial dermis. The endothelial lining is one cell layer in thickness with bland cytologic features. Intraluminal papillary projections are seen. The vascular spaces are empty.