Eruptive telangiectasia: a closer look at trastuzumab emtansine cutaneous complications in patients with breast cancer

Breast cancer, the most common malignancy in women, often involves overexpression of human epidermal growth factor receptor 2 (HER2), indicating poor prognosis. Trastuzumab emtansine (T-DM1) is an effective therapeutic option. Although it does have side-effects, these rarely include skin-related issues. However, we present here a case report of a patient with HER2-positive breast carcinoma who, while undergoing T-DM1 treatment, manifested eruptive telangiectatic macules, a rarely reported adverse effect. We conducted a literature review and identified some reports of cases where cutaneous side-effects of T-DM1 were associated with hepatic abnormalities, indicating potential systemic implications. Monitoring for liver damage, possibly through hepatic elastography, could aid in managing T-DM1-associated complications.