Miliary Metastases in Non–Small-Cell Lung Cancer
A 56-year-old woman presented to the emergency department with shortness of breath that had progressively worsened over 8 months. She had no history of tobacco use. On presentation, the patient received 3 liters of supplemental oxygen to maintain an oxygen saturation of 93%. Findings from a lung examination were notable for bronchial breath sounds in both lungs. Laboratory evaluation showed a d-dimer level of 2010 ng per milliliter (reference value, <500). A pulmonary computed tomographic angiogram showed innumerable pulmonary nodules in a diffuse pattern in both lungs. Multiple hepatic and osseous lesions were also found on subsequent imaging, including pathologic cervical fractures at the C6 and C7 levels. A core-biopsy specimen of the liver showed moderately differentiated adenocarcinoma that was positive for cytokeratin 7, negative for cytokeratin 20, and positive for thyroid transcription factor 1 on immunoperoxidase staining — findings that are consistent with a primary lung adenocarcinoma. Next-generation sequencing revealed an EGFR exon 19 deletion. Miliary metastases have been reported in cases of non–small-cell lung cancer with EGFR mutations. The patient started treatment with erlotinib and underwent posterior spinal fusion and decompression. After 1 year, the patient had a partial response to erlotinib; she was not receiving supplemental oxygen and had no shortness of breath.
