Adenocarcinoma of the Lung Mimicking Miliary Tuberculosis

Pulmonary adenocarcinoma mimicking miliary tuberculosis in a 20-year-old man: A clinical case report

Lung adenocarcinoma (LA) is the most common subtype of lung cancer with nonsignificant manifestations. Some benign conditions can mimic LA in symptoms and even chest imaging. In this case report, we are discussing a young man without any significant medical history with metastatic LA, initially presumed military TB.

Not all that is miliary is tuberculosis: Metastatic medullary thyroid carcinoma mimicking miliary tuberculosis

Medullary carcinoma of the thyroid should be considered in the differential diagnosis of miliary pattern of micronodules on chest imaging, irrespective of clinical features.

Alectinib for Miliary Lung Metastasis in ALK-Positive Lung Adenocarcinoma

Background

Miliary pulmonary metastasis characterized by tiny nodules is a rare metastatic pattern in advanced non-small cell lung cancer (NSCLC) and is usually seen in patients harboring an EGFR mutation, and amylase-producing lung cancer is highly uncommon and rarely reported in NSCLC patients who have an EGFR mutation.

Case

A 32-year-old Japanese female was found to have miliary pulmonary nodules throughout both lung fields on a chest x-ray examination during an annual health check-up. Further examination by computed tomography (CT) revealed diffuse, bilateral, miliary nodules. Blood tests showed no increased tumor marker levels, but there was a significantly increased serum amylase level. A diagnosis of ALK-rearranged adenocarcinoma was made based on the results of a mediastinal lymph node biopsy obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Treatment with alectinib resulted in rapid regression of the CT shadows and a reduction in the patient’s serum amylase level.

Conclusion

We have reported a case of ALK-rearranged NSCLC with a miliary pulmonary metastasis pattern that was sensitive to alectinib and in which the serum amylase level decreased in response to treatment with alectinib. Young patients with miliary pulmonary metastasis should be checked for all driver mutations.

Metastatic Adenocarcinoma of the Lung Mimicking Miliary Tuberculosis and Pott's Disease

Tuberculous spondylitis (Pott’s disease) is among the frequent extra-pulmonary presentations of tuberculosis (TB). The global incidence of lung adenocarcinoma is on the rise, and it is a rare differential diagnosis of miliary shadows on chest imaging. It has a predilection to metastasize to ribs and spine in particular. There is a very close clinical and radiological resemblance in the presentation of spinal metastasis of lung cancer and Potts’s disease. It poses a diagnostic challenge to clinicians particularly in TB endemic areas to arrive at an accurate diagnosis, leading to disease progression and poor outcome. We report a 54-year-old female patient presented with constitutional symptoms of on and off fever and back pain. Her chest X-ray revealed miliary shadows, and acid-fast bacilli (AFB) sputum smear and TB polymerase chain reaction (PCR) test came negative; radiological diagnosis of tuberculous spondylitis was done on computerized tomography (CT) chest and magnetic resonance imaging (MRI) spine. Subsequent bronchoscopy and bronchoalveolar lavage (BAL) cytology showed malignant cells and CT-guided lung biopsy confirmed lung adenocarcinoma with spinal and brain metastasis. Despite being started on chemo-immunotherapy and radiotherapy her outcome was poor due to advanced metastatic disease. This case highlights the significance of considering metastatic adenocarcinoma of the lung a rare but ominous possibility in the differential diagnosis of miliary shadows on chest imaging. Early bronchoscopy and biopsy must be considered in all patients presenting with miliary pulmonary lesions and spinal lesions to make a correct diagnosis, preventing an unnecessary delay in starting proper treatment and poor outcome. It also emphasizes the importance of better understanding the different radiographic features of the two common mimics, spinal tuberculosis, and metastatic spinal tumors.