endometriosis is defined as the presence of normal endometrial mucosa implantation outside the uterine cavity , . it is diagnosed in women of reproductive age . endometriosis most commonly affects pelvic organs , but it can be found in extra - pelvic organs and tissues , . the presence of endometrial tissue in or around the lung is called thoracic endometriosis syndrome ( tes ) . typically , it consists of catamenial pneumothorax , haemothorax , haemoptysis , and pulmonary nodules , . the majority of patients commonly have catamenial pneumothorax ( 73% ) , while catamenial haemothorax is present just in 14% of the cases . chest pain , dyspnoea , cough , haemoptysis , and scapular pain are the most common patients complaints . symptoms usually occur between 1  day before and 23  days after the onset of menstruation . anamnesis , imaging studies , , , histopathological examination   play an important role in the diagnosis of tes . however they all have limitations . the same symptoms are accompanied with other pulmonary diseases , radiological abnormalities are transient and there are no specific diagnostic criteria , and only one third of the cases may have histopathological confirmation of endometriosis diagnosis . tes is treated medically and surgically . when medical treatment fails , surgical resection of endometriosis damaged tissue is suggested . in line with the scare criteria , we report a case of a 36-year - old woman with thoracic endometriosis causing catamenial haemothorax . it is the first case of tes that has required urgent surgical treatment in our hospital in past fifteen years . a 36-year - old female was admitted to the emergency room ( er ) because of pain in the right side of the abdomen and chest , breathlessness and faintness lasting few hours . her past medical history was significant for long lasting iron deficiency anaemia ( she had few blood transfusions ) , infertility and two abdominal surgeries . ten years ago she underwent myomectomy , and seven years ago she had diagnostic laparoscopy because of severe bleeding during the menses ( pelvic endometriosis was diagnosed ) . during physical examination , her blood pressure was 90/60  mmhg , and heart rate 89 times per min . one litre of haemorrhagic fluid from pleural cavity was drained in the er . then , a computed tomography scan of the chest , abdomen and pelvis was performed . it demonstrated a small amount of air and heterogenic fluid in the right side of the chest after right pleural cavity drainage , and a small amount of fluid in the abdomen . however , heterogenic nodules in the uterus , and solid density masses in the lower part of the abdomen were seen . hypovolemia was corrected by the transfusion of four units of red blood cells and crystalloid liquids in the er . after that , the patient was admitted to the department of thoracic surgery for further examination and treatment . the patient was haemodinamically stable , the bleeding through the chest probe was stopped . because of that , no urgent surgery was performed . prior to video - assisted thoracoscopic surgery ( vats ) , an abdominal ultrasound was performed . the patient underwent gynaecological examination . a transvaginal ultrasound examination revealed internal genitalia and pelvic endometriosis blood clots in the right pleural cavity and suspected endometriosis lesions on the lungs , parietal pleura and diaphragm were found . 2 ) . electrocoagulation , atypical lung resection was performed , and biopsy was taken ( see fig . three months after it , there was no recurrence of postoperative chest haemothorax . due to endometriosis endometriosis most commonly affects pelvic organs , but it can be found in extra - pelvic organs and tissues , . the presence of endometrial implants in airways , pleura and lung parenchyma is called thoracic endometriosis syndrome ( tes ) , , . it consists of catamenial pneumothorax , catamenial haemothorax , catamenial haemoptysis , and pulmonary nodules , . the majority of patients commonly have catamenial pneumothorax ( 73% ) , while catamenial haemothorax is present just in 14% of the cases , followed by 7% of haemoptysis and 6% of lung nodules . there are several different proposed theories for the formation of te , , , , . the first hypothesis is lymphatic or haematogenous embolization from the uterus , , , , , the second presents coelomic metaplasia theory , , , , , and the third proposes retrograde menstruation during which endometrial tissue from the uterus and fallopian tubes migrates via abdomen and congenital or acquired diaphragmatic defects into the pleural cavity , , , , . anamnesis , imaging studies , , , histopathological examination   play an important role in the diagnosis of te . chest pain , dyspnoea , cough , haemoptysis , and scapular pain are common patients with te complaints . symptoms usually occur between 1  day before and 23  days after the onset of menstruation , but they also can present in the inter - menstrual period . moreover , the same symptoms may be accompanied by other pulmonary diseases such as pulmonary malignancy or tuberculosis . during the physical examination , diminished or absent chest x - ray reveals normal   or non specific findings such as pneumothorax , pleural effusions , or pulmonary nodules . ultrasonography role is also important in diagnosis of endometriosis , due to the fact that te may go together with pelvic and abdomen endometriosis . in our case , the patient complained of pain in the right side of the abdomen and chest , and shortness of breath . ultrasonography showed internal genitalia and pelvic endometriosis . both chest computed tomography ( ct ) and magnetic resonance imaging ( mri ) however , it is important to know that radiological abnormalities are transient . the first line imaging method is ct , but it is poorly specific . a ct scan may show endometrial implants ( as hypo - attenuating areas ) , ground - glass infiltrates , single or multiple nodular lesions or bullous formations , . it demonstrates a hyperintense lesion of endometriosis on t1- and t2-weighted images . in our case , a ct scan of the chest it revealed a small amount of air and heterogenic fluid in the right side of the chest and abdomen , heterogenic nodules in the uterus , solid density masses in the lower part of the abdomen . the role of bronchoscopy in the diagnosis of endometriosis is also limited , because most pathologic features are located in the periphery . histopathological confirmation of endometriosis is also difficult : according to the literature , histopathological diagnosis may be obtained in only 1/3 of the cases . vats may be used as a gold standard for direct visualisation of endometrial lesions in the thorax and tissue biopsy . the target of medical treatment is focused on the suppression of ovarian estrogen secretion , . for this purpose , some authors suggest chemical pleurodesis in the presence of pleural effusion , haemothorax and pneumothorax before major surgical procedures . more aggressive surgical treatment are removal of ectopic endometrial tissue , closing diaphragmatic defects , abrading of pleural surfaces , and pleurectomy , . ectopic endometrial implants in the lungs are removed by wedge resection or limited lung segmentectomy . in our case , tes should be suspected in a reproductive age woman with exacerbating symptoms during the menstruation . a great attention should be paid to the importance of taking a thorough history ( especially careful gynaecological history ) , a comprehensive physical and radiological examination . when possible , tes treatment should be started with medicine . our case report shows that tes may be the cause of dangerous situation when an urgent operation must be performed . not all clinicians know that tes sometimes might complicate to pneumothorax or massive bleeding , which might cost a patient s life . we suggest performing vats as soon as possible for reproductive age woman with unknown aetiology of pneumothorax or haemothorax to find out the lesions in pleural cavity and start appropriate treatment on time .
highlightsthe diagnosis of thoracic endometriosis is complicated , because it has no specific symptoms and signs , and often delayed . 
 tes should be suspected in a reproductive age woman with exacerbating symptoms during the menstruation.tes treatment should be started with medicine . if medical therapy fails , surgical treatment should be performed.our case report shows that tes may be the cause of dangerous situation when an urgent operation must be performed . 
 it is the first case of tes that has required urgent surgical treatment in our hospital in past fifteen years . 
 not all clinicians know that tes sometimes might complicate to pneumothorax or massive bleeding , which might cost a patient s life . 
 we suggest performing vats as soon as possible for reproductive age woman with unknown aetiology of pneumothorax or haemothorax to find out the lesions in pleural cavity and start appropriate treatment on time .