Supplementary Material for: Chemo- and Immunotherapy in a Patient with Anti-TIF1γ-Positive Paraneoplastic Dermatomyositis in Adenocarcinoma of Unknown Primary Origin: A Challenging Path from Diagnosis to Treatment – a Case Report

A 35-year-old female patient presenting with photosensitive erythema initially consulted a general practitioner. After a dermatological evaluation, she was diagnosed with anti-TIF1γ-positive dermatomyositis. Due to a painful axillary lymph node, further ultrasound investigation led to the diagnosis of adenocarcinoma of unknown primary origin with paraneoplastic dermatomyositis, initiating a complex, interdisciplinary treatment approach. A novel approach was initiating an immunotherapy due to cancer disease despite paraneoplastic autoimmune disease, what adds to literature that immunotherapy is not generally contraindicated in these patients. The treatment protocol was found in a combination of dose-dense corticosteroids, chemotherapy, immunotherapy, surgery and radiotherapy and led to a complete remission of both dermatomyositis and neoplastic disease. This case underlines the importance of an individual and careful interdisciplinary treatment protocol with regularly evaluating the therapeutic outcome of symptoms and adverse effects.