Pulmonary endometriosis: a rare cause of hydropneumothorax

Pulmonary involvement in endometriosis is well described in the literature but asymptomatic significant hydropneumothorax is considered an unusual presentation. It classically coincides with a menstrual cycle and can be a cause of recurrent disease. We present a young lady who was found to have an incidental asymptomatic right hydropneumothorax on a pre-employment health screen. She comes from an endemic area of tuberculosis, thus we pursued several diagnostic tests to rule it out. A diagnosis of catamenial hydropneumothorax was reached through a pleural biopsy. This case highlights the importance of adopting a systematic approach in managing uncommon presentations.