On physical exam the patient is well-appearing, alert and in minimal distress. The patient has a respiratory rate of 22, oxygen saturation of 96% on room air, normal blood pressure, temperature and heart rate. Upon examining the chest, no retractions or accessory muscle use is noted. Auscultation reveals decreased breath sounds over the entire right lung field The remainder of the physical examination is grossly unremarkable. You place a nasal cannula with 3L of O2 flowing and basic laboratory studies are drawn right after you order a portable chest radiograph. It comes as no surprise that your patient has a large pleural effusion on the right side. Being curious as to what could be causing a pleural effusion in such a young patient, you obtain informed consent and put a small needle into the pleural space hoping to acquire a small sample of the fluid to send to the lab for further analysis. To your surprise, you pull back on the plunger to find that the pleural effusion is not a clear or straw colored fluid, but rather is dark red blood. Now the real thinking begins.
Discussion:
We have a hemodynamically-stable young female complaining of dyspnea in the setting of decreased breath sounds on the right side and a bloody pleural effusion.
Trauma and iatrogenic causes are the most common etiologies of hemothorax in a young person. However, this patient does not disclose any history that would fit these maladies so we must probe deeper. Other causes of spontaneous hemothorax that could quickly lead to hemodynamic instability include pulmonary embolism with infarction or a leaking thoracic aneurysm. These causes are also very unlikely. The most common major medical disorder that causes hemothorax is malignancy; either primary or metastatic. This patient does not really seem to fit that picture either.
Bullous emphysema is a less common cause of spontaneous hemothorax, though the patient has no such history and does not smoke. Along the same lines, a spontaneous pneumothorax could concomitantly occur or cause a hemothorax via tearing of pleural adhesions. No pneumothorax is seen on the chest X-ray in our patient, but a CT scan of the chest once again can further evaluate for a small pneumothorax that can not be visualized on chest radiograph. Additionally, it will reveal if the patient does in fact have bullous emphysema.
Tuberculosis should not be forgotten as a cause of hemothorax. However, in this patient, it is not a strong candidate as the patient denies fever, night sweats and weight loss and has no known exposure to tuberculosis or other risk factors. In any event, she must be ruled out for TB to protect her, her family and the community. A PPD can be placed or an acid-fast stain and culture can be done on the aspirated pleural fluid.
Serositis. As we move further down the differential of uncommon causes of hemothorax, another disorder to consider is serositis secondary to autoimmune diseases such as rheumatoid arthritis or lupus (SLE). If lupus is suspected, we could obtain an ESR, ANA, anti-ds DNA and antiphospholipid antibody levels and evaluate for other criteria for SLE including oral ulcers, arthritis, photosensitivity, hemolytic anemia, leukopenia, thrombocytopenia and urine protein or casts.
Pathology in the abdomen or pelvis may occasionally lead to spontaneous hemothorax if a diaphragmatic rent is present or some sort of reactive process irritates the diaphragm from below. Pancreatitis and pancreatic pseudocyst can lead to a bloody pleural effusion via a pancreatic fistula. Our patient, however, has no history of abdominal pain or vomiting and has a soft abdomen. If suspicion is high enough, a lipase level can be checked and an ultrasound or CT scan of the abdomen can evaluate for a pseudocyst. A CT of the abdomen and pelvis would also be part of the work up for Meig’s syndrome, which is the triad of ascites, pleural effusion and benign ovarian tumor. While our patient has a right-sided effusion consistent with a classical presentation of Meig’s syndrome, she has no evidence of ascites.
Another rare cause of hemothorax is thoracic endometriosis syndrome with catamenial hemothorax. As noted, the patient is currently on her menses, which on further questioning started three days ago along with the dyspnea. Interestingly enough, her prior episodes of dyspnea also occurred during her menses. I think we have our answer.
Thoracic endometriosis syndrome presents in an array of different manifestations including pneumothorax, hemothorax, hemoptysis and pulmonary nodules, with the distinguishing feature of recurrence during menses. Catamenial hemothorax is the second most common manifestation behind catamenial pneumothorax, accounting for 14% of known cases. The right side is affected over 80% of the time and the typical patient is nulliparous, black and in the fourth decade of life. Pelvic and/or abdominal endometriosis is associated with the majority of cases. The diagnosis is largely clinical since only 70% of surgically managed cases result in pathological diagnosis. Further, pathological identification is hindered if a specimen is taken after the menstrual period as thoracic endometrial tissue also undergoes cyclic expansion and recession.
This patient’s pleural fluid analysis is consistent with a hemothorax. A CT angiogram of the chest was done which shows no pulmonary embolism or aortic dissection or aneurysm and is significant only for a large right pleural effusion. With a potential diagnosis in sight, chest tube thoracostomy is performed on the right chest and 1200 mL of bloody fluid is drained. The patient’s dyspnea improves and she is admitted to the cardiothoracic surgery service with gynecology following the case in consultation.
Treatment of thoracic endometriosis varies, but is usually a combination of medical and surgical therapy. Surgically, thoracotomy or VATS (Video-Assisted Thoracoscopic Surgery) is utilized to remove pleural or diaphragmatic implants. Medical therapy aims to minimize estrogen secretion. Danazol suppresses the surge of leuteinizing hormone during menses, leading to an anovulatory state. Gonadotropin-releasing hormone agonists provide negative feedback on the anterior pituitary resulting in decreased follicle-stimulating hormone and leuteinizing hormone secretion and is the treatment of choice if the patient wishes to preserve her fertility. Hysterectomy and oophorectomy can also be performed, but there have been cases of recurrence even after those procedures.
During the admission, our patient had a chest tube output of 200 mL/day. The pleural fluid cytology and acid-fast stain/culture were all negative. A CT scan of the pelvis was completed and revealed fullness in Douglas’ pouch that was thought to possibly be consistent with endometriosis. A thoracotomy ended up being performed with resection of several dark orange plaques from the right lower lobes. No diaphragmatic lesions were noted. Pathology was consistent with endometrial tissue without malignancy. Histology and culture of the pleural tissue was negative for acid-fast bacilli. Laparoscopy revealed several pelvic endometrial implants. All of these findings confirm our suspicion for a final diagnosis of catamenial hemothorax secondary to thoracic endometriosis.