The pathogenesis of pneumothorax in miliary tuberculosis is unclear, but the following mechanisms can be considered: caseation or necrosis of subpleural miliary nodules and their subsequent rupture can cause pneumothorax. On the other hand, acute miliary dissemination may lead to emphysematous changes. This mechanism may explain the bilateral, simultaneous, and/or recurrent pneumothoraces.2,4 Despite this knowledge, it is not clear why a pneumothorax complicating miliary tuberculosis is commonly left-sided.
It has been noted that surgical pleurectomy should be attempted early in simultaneous bilateral secondary spontaneous pneumothorax.5 In miliary tuberculosis, open thoracotomy should not be considered until the patient has received antituberculous therapy for at least several weeks. The initial treatment for nearly every patient with a secondary spontaneous pneumothorax should be tube thoracostomy.
In this patient, at the end of the twelfth month of antituberculous therapy with corticotherapy, the miliary pattern was unchanged and her diffusion capacity was reduced, despite the presence of good performance status. These findings clearly suggested an interstitial lung disease, such as histiocytosis X or Langerhans cell his-tiocytosis. Pulmonary histiocytosis X is an uncommon, smoking-related, interstitial lung disease that primarily affects young adults. Spontaneous pneumothorax, which may be recurrent, is a recognized feature of this disease and likely results from the destruction of lung parenchyma with associated cysts or nodules (with or without cavitation). Prior to a biopsy procedure, a high-resolution chest CT can be helpful in the diagnostic evaluation. The natural history is variable, with some patients experiencing spontaneous remission of symptoms and others progressing to end-stage fibrotic lung disease. There is no clear benefit for either corticosteroids or cytotoxic agents.11,12
The possibility of a histiocytosis X should be considered in a young adult with a miliary pattern that is unresponsive to a long duration of antituberculosis drugs and corticosteroids, particularly in the absence of neurologic findings. Tuberculosis can accompany an interstitial lung disease that is characterized by a miliary pattern. In such a condition, fever may not respond to corticosteroid therapy. Finally, tumor markers may be used in the follow-up of tuberculosis.
Bilateral spontaneous pneumothorax in a patient with miliary pattern tuberculosis. Appl Radiol.