Thoracic endometriosis syndrome posing diagnostic and therapeutic challenges in a low-resource setting: a case report

A 24-year-old single Black African female university graduate presented with cyclical chest pain of 2 years duration and intermittent shortness of breath of 6 months. The chest pain occurred exclusively around the time of her menses and involved the right side of the chest, raising clinical suspicion for a catamenial syndrome such as thoracic endometriosis syndrome. The chest pain was pleuritic, but it was not severe enough to interfere with her daily activities. She experienced breathlessness during her menstrual period, which was relieved by resting (approximately equivalent to New York Heart Association [NYHA] class II). She reported no history of palpitation, orthopnea, cough, pedal swelling, or paroxysmal nocturnal dyspnea. Her menses were regular but associated with severe dysmenorrhea and menorrhagia. She reported no history of trauma, fever, or urinary symptoms. She had no recent contact with animals. She denied a history of cigarette smoking or use of alcohol or recreational drugs. She was treated for seizure disorder during childhood, and did not experience any recent episode of seizures. She had no history of surgical intervention in the past. The patient had no history of drug allergy, and her family history was not remarkable. At presentation, her temperature was 37.2 °C, respiratory rate was 22 breaths per minute, pulse rate was 90 beats per minute, blood pressure was 110/70 mmHg, and oxygen saturation was 98% on room air. She was fully conscious and alert without any respiratory distress. The chest wall exhibited symmetry; nevertheless, the physical examination revealed dullness to percussion in the right lower lung field, accompanied by diminished breath sounds in the same zone. Her abdomen was not distended, and there was no palpable intra-abdominal mass or organomegaly. The chest X-ray showed homogeneous opacity at the right lung base accompanied by blunting of the right costophrenic angle as shown in Fig.  1 . Needle thoracocentesis yielded chocolate-colored aspirate (Fig.  2 ), which was sent for cytology. The chocolate coloration and cytological examination findings of hemosiderin-laden macrophages and pseudoglandular structures (Fig.  3 ) were suggestive of endometrial tissue. Serum CA-125 was also high at 128.7 U/mL (reference range: < 35 U/mL), indicating a potential endometriotic process. Her complete blood count and serum electrolytes were unremarkable except for mild anemia (packed cell volume of 29%) (reference range: 36–45%). Fig. 1 Chest X-ray (posteroanterior view) showing homogeneous opacity at the right lung base with blunting of the right costophrenic angle, consistent with a pleural effusion Fig. 2 Chocolate-colored pleural fluid aspirated during thoracocentesis, indicative of old hemolyzed blood Fig. 3 Cytology of pleural aspirate. a Clusters of epithelial cells with a glandular pattern suggestive of endometrial glands. b Hemosiderin-laden macrophages; evidence of previous intra-thoracic hemorrhage Chest X-ray (posteroanterior view) showing homogeneous opacity at the right lung base with blunting of the right costophrenic angle, consistent with a pleural effusion Chocolate-colored pleural fluid aspirated during thoracocentesis, indicative of old hemolyzed blood Cytology of pleural aspirate. a Clusters of epithelial cells with a glandular pattern suggestive of endometrial glands. b Hemosiderin-laden macrophages; evidence of previous intra-thoracic hemorrhage Her chest and abdominopelvic computed tomography (CT) scan revealed moderate right-sided pleural effusion of about 978 mL of cellular fluid. There was no obvious mass on the pleural cavity walls or in/on the lung, which was collapsed with margins floating in fluid. There was no mass visible on the upper surface of the diaphragm. The left pleural cavity was normal with normal lung expansion. Her uterus was normal in size and regular in outline with homogeneous density. The endometrial cavity was distended with minimal fluid collection (34 mL). Both ovaries appeared normal. There was no ascites seen. The bladder, kidneys, pancreas, gallbladder, and liver were all normal. Following a thorough assessment, the management multidisciplinary team (comprising family physicians, obstetrician and gynecologist, histopathologist, and nurses) recommended diagnostic laparoscopy/video-assisted thoracoscopic surgery (VATS) and tube thoracostomy to better assess and treat her condition. However, laparoscopic and VATS services were not available at our facility and the surrounding referral centers. Owing to personal anxiety, the patient declined tube thoracostomy despite extensive risk and benefit counseling. Respecting her autonomy, the managing team pursued a patient-centered option of therapeutic needle thoracocentesis. Subsequently, a right-sided needle thoracocentesis was performed under strict asepsis, and 937 mL of chocolate-colored aspirate was progressively drained from the patient’s right chest (Fig.  2 ). She was placed on Zoladex ® (goserelin acetate injection—a GnRH agonist), at a dose of 3.6 mg, to be administered subcutaneously every 28 days. However, the patient could not afford this monthly injection and was subsequently placed on continuous combined oral contraceptive pills. She also received oral amoxicillin–clavulanic acid for infection prophylaxis post-thoracocentesis and paracetamol for analgesia. At the 3-month follow-up, the patient reported complete relief from her cyclical chest pain and shortness of breath, as well as significant improvement in her dysmenorrhea. A repeat chest X-ray confirmed the resolution of her pleural effusion. She continues to be asymptomatic on continuous combined oral contraceptive pills (COCPs) and is on long-term follow-up for recurrence.

Endometriosis is a chronic gynecological disorder characterized by the presence of endometrial-like tissue outside the uterine cavity, which commonly affects the pelvic organs such as the ovaries, pelvic peritoneum, and uterosacral ligaments. It affects approximately 10% of women of reproductive age and is associated with symptoms such as dysmenorrhea, chronic pelvic pain, and infertility [ 1 ]. While most cases of endometriosis are confined to the pelvic organs, extrapelvic endometriosis accounts for about 12% of cases and can affect almost any organ system, including the thoracic cavity. [ 2 ]. Thoracic endometriosis syndrome (TES) is a rare and often underdiagnosed condition that can present with a wide range of respiratory symptoms, including catamenial pneumothorax, hemothorax, and hemoptysis [ 3 , 4 ]. The diagnostic process is notably complicated in low-resource environments, where restricted access to modern imaging modalities (for example, computed tomography [CT] scans) and specialized surgical interventions (for example, video-assisted thoracoscopic surgery [VATS]) frequently results in misdiagnosis as other respiratory disorders, leading to delayed or inappropriate treatment [ 5 ]. Several theories have been proposed to explain the mechanisms of TES, including the theory of retrograde menstruation, coelomic metaplasia theory, lymphovascular microembolization theory, and the bronchoconstriction theory, but the pathophysiology of thoracic endometriosis syndrome remains poorly understood [ 6 ]. The most widely accepted theory involves the trans diaphragmatic passage of endometrial tissue from the pelvis to the thorax likely through diaphragmatic defects via lymphatic or hematogenous spread [ 6 ]. This theory is supported by the high prevalence of concomitant pelvis endometriosis and frequent finding of diaphragmatic lesions in patients with thoracic endometriosis syndrome [ 7 ]. Clinical suspicion is key to diagnosing this condition, especially in patients with recurrent catamenial and respiratory symptoms. However, in low-resource settings, where diagnostic tools may be scarce or even unavailable, making a diagnosis is even more challenging [ 7 ]. This case report highlights a rare presentation of thoracic endometriosis syndrome in a low-resource setting, emphasizing the diagnostic challenges and the need for increased awareness of extrapelvic manifestations of endometriosis among healthcare providers. It is one of the causes of hemothorax in women of child-bearing age. It is rare and uncommon in our environment. Making a diagnosis can be very challenging in resource-poor settings such as ours. We, however, carried out some investigations on the basis of availability. The results of these investigations reinforce our clinical diagnosis. Physicians are encouraged to consider TES as one of the differentials in managing hemothorax. Early recognition and appropriate management of thoracic endometriosis syndrome can significantly improve patient outcomes, particularly in resource-constrained environments such as ours where diagnostic delays are more likely.

This case report highlights the complexity of thoracic endometriosis syndrome, emphasizing the need for multidisciplinary collaboration in diagnosis and management. TES should be suspected in women of reproductive age presenting with cyclical pneumothorax, hemoptysis, or chest pain. In low-resource settings where diagnosis remains challenging owing to the nonspecific nature of imaging and the lack of definitive biomarkers, clinicians can rely on a high index of suspicion based on clinical history and employ affordable hormonal therapies such as continuous COCPs as first-line suppression. Awareness among medical practitioners is critical to improving early detection and reducing misdiagnosis. While surgical and medical options exist, multidisciplinary patient-centered management strategies should be prioritized. Further research is required to optimize diagnostic protocols and establish standardized treatment guidelines to improve patient outcomes.

The index case is a 24-year-old woman with TES of about 2 years duration who presented to our clinic; this represents a rare condition in our setting. Her presenting symptoms have been affecting her quality of life, leading to frequent visits to the hospital and admissions. Owing to a high index of suspicion and a history of chest symptoms during her menstrual period, we suspected endometriosis of the lung tissue. Hence, we commenced various investigations on the basis of the resources locally available. The cyclical pleuritic chest pain and associated breathlessness are classic of TES, with catamenial pneumothorax [ 3 , 8 ]. Thoracic endometriosis syndrome is associated with a significant impact on quality of life, with recurrent symptoms leading to frequent hospital visits and surgical interventions, which were experienced by our patient. Thoracic endometriosis syndrome (TES) is a rare manifestation of endometriosis, typically presenting with catamenial pneumothorax, hemoptysis, hemothorax, or pulmonary nodules. Several studies have highlighted the varied clinical presentations and pathophysiological mechanisms of TES. Catamenial pneumothorax is the most common presentation and often involves diaphragmatic defects [ 8 ]. Thoracic endometriosis syndrome cases can be misdiagnosed as primary lung diseases owing to their nonspecific radiological findings [ 3 ]. Compared with peritoneal endometriosis, which has well-defined diagnostic criteria, TES remains challenging to diagnose owing to its intermittent and often subtle symptoms. The clinical presentation of thoracic endometriosis syndrome is often delayed or misattributed to other respiratory conditions, leading to misdiagnosis and inappropriate treatment [ 10 ]. Diagnostic challenges arise from the absence of specific biomarkers, and imaging findings are often nonspecific. This case underscores the diagnostic dilemma posed by thoracic endometriosis syndrome, emphasizing the need for a high index of suspicion in women of reproductive age with cyclical thoracic symptoms. Awareness among gynecologists and pulmonologists is crucial for early recognition. Management of TES typically involves a combination of surgery (VATS for pleurodesis, resection of endometrial tissue implants) and hormonal suppression to prevent recurrence [ 9 ]. The choice of treatment—whether hormonal therapy, surgical intervention, or a combination—depends on symptom severity, recurrence risk, and patient preferences. A study suggested that video-assisted thoracoscopic surgery (VATS) provides definitive treatment, whereas another study emphasized the role of prolonged hormonal suppression in recurrence prevention [ 5 ]. Our patient’s care was directly impacted by resource limitations, including unavailability of laparoscopic services and the patient’s inability to afford first-line GnRH agonist therapy. This is a common scenario, especially in a low-resource setting, such as ours, where patients may have to pay out-of-pocket for investigations and treatment owing to limited or lack of insurance coverage. However, she benefited from both drainage, which is a form of surgical intervention, and use of hormonal agents. The successful use of continuous COCPs aligns with the principle of inducing a pseudo-pregnant state to suppress endometriosis. While robust data on COCPs specifically for TES are limited, their efficacy in pelvic endometriosis is well-established and they represent a widely available and affordable alternative [ 1 ]. A critical aspect of this case report was the patient’s refusal of a chest tube. This highlights the importance of effective communication and shared decision-making. By respecting her preference and offering a viable alternative (therapeutic thoracocentesis), the team adhered to the ethical principles of autonomy and beneficence, ultimately achieving a successful outcome.

This case report has several limitations. Its single-case perspective limits generalizability. Long-term data beyond 3 months are not yet available to access recurrence risk, but the patient is on long-term follow-up. Additionally, histopathological confirmation of ectopic endometrial tissue could not be performed. However, in this case, we relied on the cytological analysis of the pleural fluid. Future research should focus on improving noninvasive diagnostic techniques, such as the use of specific biomarkers or advanced imaging modalities. Large-scale studies comparing surgical versus medical management strategies would provide clearer guidelines for optimal treatment. Additionally, genetic or molecular profiling of thoracic endometriosis syndrome may help in understanding its pathogenesis and potential targeted therapies.