Systemic sclerosis (SSc) is a complex autoimmune disease marked by vasculopathy, fibrosis, and multisystem involvement. Interstitial lung disease (ILD) and pulmonary hypertension (PH) are major mortality contributors. Importantly, SSc is associated with an increased risk of malignancy. This report presents a challenging case of SSc with severe Raynaud's phenomenon (RP), digital gangrene, calcinosis cutis, extensive ILD, severe PH, and right heart failure. The patient underwent mesenchymal stem cell therapy (MST), following which she developed breast cancer and chemotherapy-related complications, ultimately leading to death. This case highlights the need for timely intervention, screening for malignancy, and awareness of potential therapy-related risks in SSc.