Violaceous rash on the face, upper body, and thighs

A woman in her 30s presented with a two month history of painless, non-itchy reddish purple plaques and nodules which first appeared on her abdomen and gradually spread to her upper body and thighs (fig 1). She had no relevant medical history and was not taking any medication.bmj;394/aug20_5/e100277/F1F1f1Fig 1On examination, there were multiple violaceous patches and nodules on her abdomen, chest, back, upper arms, and thighs. The lesions were indurated and non-tender on palpation.Differential diagnoses included cutaneous metastases from a solid tumour or cutaneous involvement of a haematological malignancy. Given the lack of tenderness, ulceration, discharge, or signs of systemic inflammation, infective and inflammatory dermatoses were considered less likely.Full blood count showed a white blood cell count of 3.06×109/L (reference range, 3.5 to 9.5×109/L). Liver and renal function, coagulation, autoimmune, and immunodeficiency profiles were within normal limits.An abdominal skin biopsy was done. Histopathological examination and immunophenotyping were consistent with a…