DP13 Keep calm and shoulder on: a lesion that can’t be shrugged off

Abstract A 76-year-old woman presented with a 4-year history of an asymptomatic progressive 10 × 13-cm, irregular, erythematous patch on the right posterior shoulder. Around onset, she had treatment for left-breast cancer with mastectomy and left axillary node clearance. The second cycle of adjuvant chemotherapy (5-fluorouracil, epirubicin, cyclophosphamide) caused right-upper-limb phlebitis and lymphangitis with permanent damage to local vasculature. She later had further systemic anticancer therapy, followed by adjuvant radiotherapy to the left chest wall. She was on hydroxychloroquine for long-standing rheumatoid arthritis, having previously received methotrexate and sulfasalazine. An incisional biopsy showed dilated, sinusoidal lymphovascular channels in the dermis, lined by CD31+, D2-40+, CD34−, c-Myc− and human herpesvirus 8-negative endothelial cells with hobnail nuclei without atypia. These findings suggested an acquired progressive lymphangioma (APL) or lymphatic subtype of an atypical vascular lesion (AVL). A magnetic resonance imaging scan confirmed a mixed high and low signal, with a vascularized plaque involving the dermis and subcutaneous fat, and multiple vessels extending from its deep surface into underlying fat. Following multidisciplinary review, observation was advised, in preference to extensive surgery. APL (or benign lymphangioendothelioma) is a rare locally infiltrative vascular tumour affecting people of all ages and genders, which most frequently involves the limbs, breast, head and neck. There have been fewer than 50 reports to date. It usually presents as a solitary brownish-red or violaceous macule or plaque, although multiple papules/nodules and mass lesion are described. Iatrogenic or other injuries that have potential to cause lymphatic obstruction often precede onset. Excision is curative. A case at an irradiated site progressing to angiosarcoma has been reported. AVL is a comparatively more common vascular proliferation most commonly affecting women aged > 50 years, approximately 3–6 years after radiotherapy for breast cancer, usually at the irradiated site and rarely outside it. It presents as single or multiple erythematous papules, patches or plaques. It has two histological subtypes: vascular and lymphatic. As it can rarely progress to angiosarcoma, surgical resection is advised. Histologically, APL and the lymphatic subtype of AVL may be indistinguishable. Both are characterized by a vascular proliferation lined by a single layer of flat or hobnail endothelial cells without atypia, which stain for similar lymphatic and vascular markers. Some cases described in the literature as APL in irradiated areas are possibly the lymphatic subtype of an AVL. As there was no latency between irradiation and onset, our case is more likely APL, rather than AVL outside the field of irradiation.