Nocturnal Hypoxemia, an Unusual Presentation of Pulmonary Endometriosis: A Case Report

Thoracic endometriosis syndrome is a rare condition with four main presentations: pneumothorax, hemothorax, hemoptysis, and lung nodules. We describe an incidental diagnosis of pulmonary endometriosis in a patient admitted with acute pyelonephritis, and developed acute hypoxemia and a productive cough of blood tinted sputum, on the third day of hospitalization. Her thoracic x-ray showed diffuse pulmonary infiltrates, and a small pleural effusion. Chest computerized tomography scan had extensive areas of ground glass opacifications scattered predominantly in the medulla of both lungs. Bronchoalveolar lavage cytology showed small groups of cells in arrays compatible with endometrial cells, which confirmed the diagnosis of pulmonary endometriosis. On the seventh day of hospitalization, after the end of her menstrual bleeding, oxygen supplementation was discontinued, and hypoxemia did not recur. A chest x-ray at the ninth day of hospitalization was normal. Pulmonary endometriosis should be considered in a patient who has unexplained episodes of nocturnal hypoxemia associated with hemoptysis, especially if there is periodicity. J Med Cases. 2012;3(6):352-354 doi: https://doi.org/10.4021/jmc778w