INTRODUCTION: Endometriosis is defined as the presence of endometrial glands in stroma outside the confines of the uterine cavity. Thoracic endometriosis is a rare disorder characterized by the presence of functioning endometrial tissue within the pleura, the lung parenchyma, or the airways. In this report, we describe a patient who presented with a large lung mass and was found to have thoracic endometriosis.
CASE PRESENTATION: A 47-year-old nurse, nonsmoker, presented with 3-4 months of cough associated with intermittent hemoptysis and epistaxis. She denied chest pain, shortness of breath, fever and weight loss. PPD was negative. Physical examination as well as lab data were unremarkable except for an ACE level of 67 and mild anemia (hemoglobin of 11.3). Chest radiograph revealed a large, well circumscribed mass in the left lower lobe. Chest CT scan showed a 5.6x5.4cm mass in left lower lobe with areas of necrosis within the mass (Fig. 1). PET scan revealed intense FDG activity in left lower lobe and increased FDG uptake in posterior pelvis –uterus vs. colon. No abnormality was found on colonoscopy. Endometrial biopsy was negative for malignancy. Patient then underwent bronchoscopy, which showed no endobronchial lesions, but histopathology from transbronchial biopsy was read as spindle and epithelioid neoplasm, unclassified, involving subepithelial bronchial mucosa. The tumor did not appear to originate from the overlying bronchial epithelium. The suspicion for malignancy was high and patient was taken for left lower lobectomy with lymph node sampling. Histopathology was consistent with parenchymal endometriosis with no evidence of malignancy (Fig. 2). The patient was cured of symptoms but developed severe abdominal pains 4-5 months after thoracotomy, which were attributed to abdominal and pelvic endometriosis visualized on CT scan. She underwent total hysterectomy with bilateral salpingo-oophorectomy and excision of endometrial tissue present on the intestinal wall.
DISCUSSIONS: Thoracic endometriosis is a rare disorder. Since its initial description in 1956, more than 110 case have been described (1). The four major presentations of thoracic endometriosis include catamenial pneumothorax(73%), catamenial hemothorax(14%), catamenial hemoptysis(7%) and lung nodules(6%).The mean age at presentation is 35 years(19-54 years). Symptoms of thoracic endometriosis usually occur 1-2 days of the onset of menses. Several hypotheses have been proposed to explain the pathogenesis of pelvic endometriosis. The most plausible states that retrograde menstruation causes movement of endometrial tissue through the fallopian tubes which subsequently fails to clear from the peritoneal cavity through normal mechanisms. Endometrial tissue can then move into the thoracic cavity either through congenital diaphragmatic defects (more common on the right) and/or via microembolization through the pelvic veins (2). Successful treatment requires both eradication of existing thoracic endometrial tissue and prevention of reseeding from the pelvis. Medical treatment consists of suppression of the ectopic endometrium by interfering with ovarian estrogen secretion by suppressing ovulation using oral contraceptives, progestins, danazol, or gonadotropin-releasing hormone analogs. Recurrence rate with medical therapy is approximately 50 percent at 18 months but is reasonable to attempt before a surgical intervention.
CONCLUSION: A high index of suspicion is needed in order to make a clinical diagnosis of thoracic endometriosis when a patient of reproductive age presents with intermittent chest pain, pneumothorax or hemoptysis.
DISCLOSURE: Ganesha Santhyadka, None.