Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Catemenial Pneumothorax
- Radiologic Findings
- Fig 1. Chest PA shows 1st episode of right pneumothorax and atelectasis of right lower lobe (2017-08-01)
Fig 2. Chest PA shows 2nd episode of right pneumothorax and atelectasis of right lower lobe (2017-09-01)
Fig 3. Chest PA shows 3rd episode of right pneumothorax and atelectasis of right lower lobe (2018-01-08)
Fig4. Lung window setting of chest CT scan shows right pneumothorax. There is no parenchymal lesion in both lungs.
Fig 5. Thorough history from the patient revealed that her symptoms began during menses at each episode. Catamenial pneumothorax was clinically suspected. Explorative VATS was performed. Intraoperative finding showed multiple pores at the right diaphragm, suggesting catamenial pneumothorax. The result of excisional biopsy of the diaphragm was mild chronic inflammation and no endometriotic tissue was documented.
- Brief Review
- Catamenial pneumothorax (CP) is a spontaneous recurring pneumothorax that occurs in women and is correlated with menses. CP was generally considered a rare entity. Its incidence in large epidemiological studies is only 3-6%. It is believed that CP is underdiagnosed and the incidence of CP has been often underestimated. CP involves the right side in the vast majority of cases. It can be left sided or rarely may be bilateral.
CP etiology is most likely multifactorial in origin involving a combination of different mechanisms. Currently, three different mechanisms have been proposed, namely: (1) transdiaphragmatic passage of peritoneal air, originating from the genital tract, through the fallopian tubes; (2) sloughing of endometrial implants from the visceral pleura, with subsequent air leakage; and (3) alveolar rupture due to prostaglandin-induced bronchiolar constriction or obstruction by bronchiolar endometrial implants. Transdiaphragmatic passage of air is currently the most widely accepted hypothesis, although it cannot explain every case. Cervical mucus plug liquefaction during the menstrual period allows passage of external air through the uterine cavity into the peritoneal one. Air may then reach the pleural space through diaphragmatic fenestrations, helped by negative intrathoracic pressure, implying the occurrence of pneumoperitoneum as an intermediate step.
The typical clinical presentation of CP involves spontaneous pneumothorax during or preceding menses, usually manifested with pain, dyspnea and cough.
Although there are generally no specific diagnostic imaging criteria, CT remains the first-line imaging method, as it can rule out other diagnoses and map the lesions for surgery if necessary. Diaphragmatic implants may appear as hypo-attenuating areas on CT, sometimes associated with an iso-attenuated component, depending on the size and blood content. Other rare imaging findings include pneumoperitoneum co-existing with right pneumothorax, small diaphragmatic defects, nodular appearance of the diaphragm on chest X-ray and CT corresponding to partial intrathoracic liver herniation.
Characteristic operative findings include diaphragmatic defects, and/or spots or nodules (usually endometrial implants) on the diaphragm, and/or the visceral and/or the parietal pleura.
Endometriosis tissue may or may not be found in the characteristic lesions. The spots and nodules are usually found to be endometrial implants. Endometrial tissue has been also found at the edges of the diaphragmatic defects, which may represent cyclical breakdown of endometrial implants. However, macroscopic evidence of thoracic endometriosis and furthermore histologically proven thoracic endometriosis is not revealed in all cases of catamenial pneumothorax.
For treatment, partial diaphragmatic resection and/or resection of visceral pleural implants, and pleurodesis, are frequently performed. In addition, hormonal treatment (GnRH) immediately after surgery is now suggested for all patients with proven CP.
- References
- 1. Visouli AN, Darwiche K, Mpakas A e al. Catamenial pneumothorax: a rare entity? Report of 5 cases and review of the literature. J Thrac Dis. 2012;4:17-31
2. Rousset P, Rousset-Jabloski C, Alifano M et al. Thoracic endometriosis syndrome: CT and MRI features. Clinical Radiology. 2014;69:323-330
- Keywords
- Pleura, Others,