P09: Unilateral cutaneous sarcoidosis of the radiotherapy field after breast cancer

Riham Gendra,¹ Alexandra Phillips² and Girish Patel²

¹University of Cardiff, Cardiff, UK; and ²University Hospital of Wales, Cardiff, UK

Sarcoidosis is a multisystem inflammatory disease of unknown aetiology, defined by the presence of noncaseating granuloma. The most common organs affected are the lungs, eyes and skin (Valeyre D, Prasse A, Nunes H et al. Sarcoidosis. Lancet 2014; 383: 1155–67). Cutaneous sarcoidosis occurs in 10–30%, usually evident at presentation, with papules or erythema nodosum (Petit A, Dadzie O. Multisystemic diseases and ethnicity: a focus on lupus erythematosus, systemic sclerosis, sarcoidosis and Behçet disease. Br J Dermatol 2013; 169: 10). The association between sarcoidosis and malignancy remains controversial. We present a 55-year-old woman with an 8-month history of a sudden-onset unilateral papulovesicular eruption of the left breast and surrounding chest wall. The left breast was painful and the patient noted fever and malaise. There had been no improvement after treatment with oral aciclovir and then topical corticosteroids. Five years earlier she had carcinoma of the left breast, treated with mastectomy, reconstruction and subsequent radiotherapy for 1 month. Examination revealed multiple uniform erythematous papules distributed over the entire left breast and the surrounding upper chest wall extending to the midline. The left breast was swollen, with a peau d’orange appearance and was exquisitely tender. Polymerase chain reaction for herpes simplex and zoster were both negative. Full blood count, urea and electrolytes, liver functions tests, C-reactive protein, uric acid, lactate dehydrogenase and QuantiFERON tests were all normal. Serum calcium level was elevated at 2.6 mmol L^–1, but serum angiotensin-converting enzyme level was normal (although the patient was on oral corticosteroids). Left breast mammography and ultrasound were normal. Chest X-ray was normal. High-resolution computed tomography of the thorax noted the skin thickening, no lymphadenopathy and left upper lobe reticulation in keeping with post-radiotherapy changes, but there was no evidence of interstitial lung disease. A skin biopsy of the papule confirmed a granulomatous disease, compatible with cutaneous sarcoidosis. The patient’s symptoms, tenderness, swelling and skin eruption improved while on a short course of prednisolone. She remains stable on hydroxychloroquine 200 mg once daily. There have been only 20 reported cases of breast cancer associated with cutaneous sarcoidosis, after a period of 0–360 months. Although postradiotherapy cutaneous sarcoidosis has previously been described, only three had had prior radiotherapy, similar to our patient. In these patients, interstitial lung involvement was reported in all cases. Six patients responded to prednisolone and hydroxychloroquine; a further three were treated with methotrexate. The case highlights the importance of recognizing prior breast cancer as a trigger for sarcoidosis that is frequently associated with interstitial lung disease.