Metastatic Lobular Breast Cancer First Appearing as Skin Nodules

What happened, in summary

A 53-year-old woman developed painless nodules in both armpits that spread across her trunk over about 5 months. She also had fatigue, loss of appetite, and a weight loss of roughly 10 kg. No breast mass was felt on examination.

Biopsy of a skin nodule showed metastatic adenocarcinoma from a breast primary, with a lobular pattern. The cancer was estrogen-receptor positive, progesterone-receptor negative, and HER2-negative. Because the first clinical presentation was already metastatic disease involving the skin, the cancer is represented as Stage IV.

She began systemic treatment with palbociclib and an aromatase inhibitor. The skin lesions initially resolved, but tumor markers continued to rise, suggesting ongoing progression. Four months after starting treatment, she developed cough, ascites, leg swelling, and pleural effusion. Although lung metastases were not identified, her overall condition continued to worsen. She died 7 months after the diagnosis of cutaneous metastatic breast cancer. Her breast cancer first became apparent through metastatic skin lesions rather than a palpable breast mass.