A Case of Miliary Adenocarcinoma of Lung Masquerading as Miliary Tuberculosis

Miliary lung adenocarcinoma is a highly deceptive and insidious form of cancer.  It commonly presents as a mass lesion accompanied with a collapsed lung and significant pleural effusion. Adenocarcinoma presenting in this manner rarely originates from other primary sites such as thyroid, choriocarcinoma, and sarcomas. This was a case of a 50-year-old housewife, who presented with increasing severity of shortness of breath, cough and loss of appetite for the past one month. Primary care physician treated her as community-acquired pneumonia, which did not improve. She then arrived at the Emergency Department with pulse oximetry to be 93% on room air. She was slightly tachycardic. Bilateral widespread miliary patches were seen on chest radiograph. Based on the history and chest X-ray, she was initially treated for miliary tuberculosis, despite negative Mantoux and negative sputum. Following worsening of symptoms, she was intubated and admitted to the intensive care unit. Bronchoscopy revealed the diagnosis of primary miliary lung adenocarcinoma. As a lesson, the radiographic miliary appearance is not confounded to tuberculosis alone, as other insidious causes should be investigated. A bronchoscope with histopathology analysis is warranted for miliary picture, especially if the Mantoux and sputum turn out to be negative.