Amyopathic Dermatomyositis Revealing Triple-Negative Breast Cancer: A Case Report and Literature Review

Amyopathic dermatomyositis (ADM) is a rare form of dermatomyositis characterized by specific cutaneous lesions without muscle involvement. It can reveal an underlying malignancy, particularly breast carcinoma. We report the case of a 48-year-old woman presenting with a skin eruption suggestive of ADM, preceding the diagnosis of triple-negative breast cancer. Paraneoplastic etiology was confirmed by the presence of anti-TIF1γ antibodies. Management included corticosteroids, intravenous immunoglobulins, and neoadjuvant chemotherapy followed by mastectomy, resulting in rapid improvement in cutaneous manifestations. One-year post-treatment, no recurrence has been observed. This case highlights the importance of systematic oncologic screening in ADM and the value of multidisciplinary care.