A 44-year-old woman with history of endometriosis on ovulatory suppressant therapy and right spontaneous pneumothorax treated with tube thoracostomy 2 months prior, presented with dyspnea and pleuritic chest pain. Physical examination was remarkable for decreased breath sounds and hyperresonance over the right hemithorax. Her labs were unremarkable. Chest radiography revealed a right pneumothorax (Figure 1). Her prior pneumothorax occurred within 2-3 days following the onset of menstruation. Previous computed tomography scanning demonstrated no emphysematous changes. She underwent video-assisted thoracoscopic surgery. There was extensive diaphragmatic attenuation such that all that remained of the central tendon was a serosal lining through which the abdominal contents were visible (Figure 2). No obvious fenestrations were noted. Due to these findings and the recurrence of pneumothorax, an aggressive approach was taken consisting of a combination of apical/superior pleurectomy, followed by mechanical pleurodesis of the remaining pleural surface including the diaphragmatic pleura, with the exception of the attenuated areas, and finally, talc pleurodesis throughout the pleural cavity for additional reinforcement. She recovered well postoperatively and was discharged on progestin. Pleural biopsy was negative for endometrial tissue. She underwent elective diagnostic laparoscopy with fulguration of extensive pelvic endometrial. On follow-up visit, she was symptom free and chest radiography demonstrated resolution of pneumothorax.
We presumed her case was catamenial in nature due to the recurrent pneumothoraces at perimenstrual onset, extensive diaphragmatic involvement, and widespread pelvic endometriosis that was evident on laparoscopy. It is the most common form of thoracic endometriosis syndrome, which includes catamenial hemoptysis, catamenial hemothorax, catamenial hemopneumothorax, and endometriosis lung nodules.1 The prevalence of this rare entity is unclear. In a retrospective study of 156 premenopausal women who were surgically treated for spontaneous pneumothorax, 31.4% could be classified as having catamenial or thoracic endometriosis-related pneumothoraces, with 8.3% of the women classified as nonthoracic endometriosis-related catamenial pneumothorax.2 Several hypotheses exist about the cause of catamenial pneumothorax: from alveolar rupture caused by vasoconstriction and bronchospasm due to high prostaglandin F2 levels during menses, to retrograde menstruation, resulting in subdiaphragmatic endometriosis.3 Diagnosis is usually suspected in a female of reproductive age presenting with pneumothorax or hemothorax, especially at perimenstrual onset. Computed tomography and magnetic resonance imaging may help aid in the diagnosis; however, direct visualization of endometrial implants and defects of the involved organs using video-assisted thoracoscopy and histopathologic confirmation is more definitive.4, 5 Surgical treatment followed by hormonal therapy has been shown to have the lowest recurrence rate of pneumothoraces.5 Surgery may involve a combination of pleurectomy along with mechanical or chemical pleurodesis; however, depending on the extent of involvement, ligation of diaphragmatic involvement and resection of endometrial implant lesion may also be performed. Hormonal therapy involving gonadotropin-releasing hormone analogues are first line, as they inhibit the growth of endometrial tissue, thus preventing recurrence.4, 5, 6 Catamenial pneumothorax remain under-diagnosed and should be considered in young women with pneumothorax, especially at perimenstrual onset. Early recognition and treatment of endometriosis may help prevent recurrent pneumothoraces and aggressive interventions.
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-Ivan Wong, MD, Ashwad Afzal, MD, Iosif Gulkarov, MD, Regis Chang, MD, Angelo Reyes, MD, Berhane Worku, MD
This article originally appeared in the June 2017 issue of The American Journal of Medicine.
