Lung adenocarcinoma first presented through skin and haemorrhagic brain metastases

What happened, in summary

A 63-year-old woman with a 30 pack-year smoking history came to hospital after 3 weeks of severe lower-back pain, nausea, vomiting, and two episodes of transient memory loss. She had also developed numerous lumps across her chest, back, abdomen, neck, breasts, axilla, groin, and thigh. The first lump she noticed, near the upper outer right breast, had enlarged from pea-sized to roughly the size of a tennis ball. A core biopsy of a right thigh lesion showed poorly differentiated adenocarcinoma. The tumour was strongly positive for TTF-1, CK7, and CEA and negative for breast and other organ markers, establishing a lung primary. PD-L1 expression was 10%, while EGFR, ALK, ROS1, and BRAF testing was negative. Imaging demonstrated widespread metastatic disease, including multiple cutaneous deposits and haemorrhagic brain metastases. She was diagnosed with metastatic poorly differentiated lung adenocarcinoma. A multidisciplinary team involving medical oncology, radiation oncology, pulmonology, and palliative care planned treatment. She received whole-brain radiotherapy extending to C2, with 30 Gy delivered in 10 fractions. Treatment caused only mild hair loss and dermatitis. Combination chemotherapy and immunotherapy were planned next, but her performance status deteriorated quickly after radiation. She chose hospice care without starting systemic therapy and died from the malignancy within 6 weeks of her initial emergency presentation. The unusually visible skin lesions were the first sign of a rapidly progressive, widely metastatic lung cancer.