Rapidly Progressive Stage IV Lung Adenocarcinoma With a Miliary Imaging Pattern

What happened, in summary

A 64-year-old man presented after two to three weeks of dry cough, frontal headache, and generalized muscle and joint pain. His history included successfully treated prostate cancer, hepatitis C, and more than 50 pack-years of cigarette use. Chest imaging showed innumerable tiny pulmonary nodules in a miliary pattern, which initially raised a broad differential including infection and metastatic disease.

Tissue obtained from a lymph node supported primary lung adenocarcinoma. The tumor was TTF-1-positive and negative for p40, chromogranin, and synaptophysin. Molecular testing found no EGFR, ALK, or ROS1 alteration, and PD-L1 expression was 5%–10%. He was diagnosed with stage IV lung adenocarcinoma. Brain MRI showed at least six small enhancing lesions considered suspicious for metastases, and he received whole-brain radiation with minimal improvement.

At first, bone imaging was negative and he denied bone pain. About one month later, his functional status declined sharply and he developed diffuse body pain; additional imaging suggested new bone and liver involvement. A combination of pembrolizumab, carboplatin, and pemetrexed was considered, but the disease progressed too quickly for treatment to begin.

He died approximately four months after diagnosis while being transported to inpatient hospice. The report emphasized the unusual miliary appearance and the aggressive course of his EGFR-negative lung cancer.