Thoracic endometriosis syndrome diagnosed by dry thoracoscopy: Novel diagnostic method for a rare disease

ABSTRACT

Endometriosis is an ectopic implantation of uterine tissue and can affect the thoracic cavity, resulting in Thoracic Endometriosis Syndrome (TES). TES is rare and presents with catamenial pneumothorax, haemothorax, and hemoptysis, often coinciding with menstruation. We report a case of a 46-year-old female with a decade-long history of hemoptysis and periodic chest pain associated with her menstrual cycle. High-resolution CT scans revealed persistent pneumothorax and pleural nodules. A dry thoracoscopy was performed, and biopsies confirmed the diagnosis of TES through histopathology and immunohistochemistry. This case highlights the importance of considering TES in women with cyclic respiratory symptoms and demonstrates the diagnostic value of dry thoracoscopy in benign conditions of the pleura. Raising awareness among clinicians is crucial for timely diagnosis and management of TES, reducing patient morbidity.

INTRODUCTION

Endometriosis is defined as a chronic condition characterized by the ectopic implantation of functional tissue of the uterus lining. Thoracic endometriosis occurs when functional endometrial tissue is found in the thoracic cavity (pleura, lung parenchyma or airways). Clinical manifestations of thoracic involvement contribute to a cascade known as “Thoracic Endometriosis syndrome (TES)”. TES, characterized by pneumothorax, haemothorax, and hemoptysis that coincide with menstruation together with pulmonary nodules has been reported in isolated case reports.[1] It is an extremely rare condition.

We hereby report the case of a patient who presented with hemoptysis that was coinciding with her menstrual cycle and persistent pneumothorax. A temporal association of patient’s respiratory manifestations with menstruation and a high index of clinical suspicion led us to workup for Thoracic Endometriosis Syndrome. We performed a dry thoracoscopy and histopathological and immunohistochemistry analysis of biopsy samples to diagnose Thoracic Endometriosis Syndrome.

CASE REPORT

A 46-year-old female nonsmoker with no known comorbidities reported complaints of intermittent hemoptysis for 10 years, left-sided chest pain, and shortness of breath, off and on, for three years. She denied any history of fever, weight loss, recurrent childhood respiratory tract infections, cough with copious expectoration, or anti-tubercular therapy intake in the past. Her gynecological history was notable for irregular menstruation and dysmenorrhea for 20 years. On further perusal of history, the patient stated that the hemoptysis and chest pain were both periodic, beginning 1–2 days before the onset of her menstrual cycle and subsiding with the end of the menstrual period.

Physical examination revealed pallor and a hyper-resonant note on the left infra-scapular and infra-axillary areas, as well as a reduced breath sound in all lung fields of the left side on auscultation. The patient had consulted multiple local physicians in the past and had undergone five high-resolution computed tomography (HRCT) thorax scans, all of which were suggestive of persistent pneumothorax, which was always treated conservatively, with no diagnosis or alleviation of symptoms for the patient. Except for anemia (hemoglobin level of 10.6 mg/dl), routine test results were within normal limits. Ultrasound (USG) examination of Abdomen and Pelvis indicated a large, heterogeneous left ovary. The CA-125 level was 135 U/mL (range: <35 U/mL). USG screening of the thorax in M-mode revealed a barcode sign on the left side. The contrast-enhanced resolution computed tomography (CECT) of the thorax revealed a left pneumothorax with multiple visceral and parietal pleura and pericardial nodules [Figure 1].

Figure 1.

CECT thorax showed left pneumothorax

For her gynecological complaints, an endometrial biopsy was performed, which was reported as normal endometrial tissue on histopathological examination. Fibreoptic bronchoscopy was performed to rule out any infective etiology and endobronchial abnormality and was within normal limits. Due to persistent pneumothorax and pericardial and pleural nodules seen on HRCT thorax, we performed a dry medical thoracoscopy. Ulcerated lesions were found on the parietal pleura and pericardial nodules and diaphragmatic deposits were also visualized [Figures 2 and 3].

Figure 2.

Thoracoscopy revealed ulcerated lesions in the parietal pleura

Figure 3.

Thoracoscopy revealed hemorrhagic diaphragmatic deposits

The post-procedure period was uneventful and the intercostal chest drain was removed after lung expansion [Figure 4]. Forceps biopsy was taken from the diaphragmatic deposits that were reported as “multiple tissues composed of benign endometrial glands with stroma” [Figure 5] on histopathological examination. Immunohistochemistry was reported as ER (strong, 100% cells), PR (strong, 100% cells), and CD 10 positive [Figure 6].

Figure 4.

Chest xray PA view showed expanded lung after thoracoscopy

Figure 5.

Histopathology showed benign endometrialglands with stroma

Figure 6.

IHC reported as ER, PR and CD 10 positive

We diagnosed it as a case of Thoracic Endometriosis Syndrome, presenting with hemoptysis and persistent pneumothorax. Opinion from thoracic surgeon was taken and decortication was advised. The patient was started on hormone replacement therapy (Dienogest and Ethinylestradiol). Following lung expansion, the intercostal drain was removed and the patient was discharged and referred to a thoracic surgeon.

DISCUSSION

Thoracic endometriosis syndrome is a rare disorder. The occurrence in the general population remains unknown.[2] It primarily affects young females in the reproductive age group. The average age at presentation is 35 (19–54 years).[2] Approximately 50–84% of patients with thoracic endometriosis have concurrent pelvic illness,[3] as was in our patient. Symptoms of thoracic endometriosis are catamenial, meaning, they have temporal association with the menstrual cycle, usually beginning within 72 hours of menses. Catamenial pneumothorax (73%), catamenial haemothorax (14%), catamenial hemoptysis (7%), and lung nodules (6%) are the four most common thoracic endometriosis presentations.[3] Pneumothorax and haemothorax are usually right-sided,[4] but it was left sided in our case.

Multiple etiological mechanisms proposed for thoracic endometriosis syndrome are retrograde menstruation, microembolization theory, coelomic metaplasia, and stem cell theory. The most probable theory appears to be the retrograde menstruation theory in which the endometrial tissue can transfer into the thoracic cavity either through congenital diaphragmatic defects (more common on the right side) or via micro-embolization through the pelvic veins.[5] Studies have revealed that CA-125 levels may be raised in TES (as was in our case), but it is a non-specific marker.[6,7] Contrast-enhanced computer tomography (CECT) of Thorax can help diagnose diaphragmatic lesions, pneumothorax, and pulmonary nodules.

Marchetti first described the process of thoracoscopy without pleural effusion, known as dry thoracoscopy, in suspected pleural malignancies and used a rigid thoracoscope.[8] We performed the novel procedure of dry thoracoscopy, done rarely and are the only ones from our country to have reported doing this procedure, to the best of our knowledge. We used a semi-rigid thoracoscope, because of our familiarity with the device, better maneuverability, and less requirement of sedation/analgesia compared to a rigid thoracoscope. We did thoracic ultrasonography to assess the pleural space for pneumothorax and to chose the point where the lung sliding sign was absent, as an entry site. The purpose of performing dry thoracoscopy was gross inspection of the pleura and diaphragm and for taking biopsies of all suspicious lesions. Thoracoscopy may reveal endometrial implants on the pleural, diaphragmatic, and pericardial surfaces and diaphragmatic perforations in patients with TES.[8] Positive estrogen and progestin receptors in an aggregated pattern along with a positive CD-10 marker could aid in the diagnosis of TES and indicate a high risk of recurrence.[9] Video-assisted thoracoscopy (VATS) remains the gold standard for diagnosis and treatment.[10] Hormone replacement therapy improves symptoms by suppressing the hormonal axis and reducing the risk of recurrence of symptoms.[10]

CONCLUSION

TES is a rare and complex condition, the diagnosis of which is often delayed or missed by clinicians leading to significant morbidity and distress to the patient. TES should be suspected in any reproductive age group woman with exacerbation of respiratory symptoms during menstruation. Thorough history taking, including gynecological history, together with a comprehensive physical examination and radiological investigations should be done. This index case report from our country shows that dry thoracoscopy performed in carefully selected patients of persistant pneumothorax can clinch the diagnosis, with minimal intraprocedure discomfort and early post procedure recovery.

We are reporting this case to establish the role of dry thoracoscopy in pleural diseases and to increase awareness regarding TES and its further workup amongst pulmonologists.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.