Recurrent catamenial pneumothorax in an adolescent: A case report with review of diagnostic and therapeutic challenges

A 14-year-old girl with a history of menarche at age 11 and heavy menstrual bleeding initially presented to the emergency department with right lower quadrant abdominal pain. Computed tomography (CT) of the abdomen and pelvis ruled out appendicitis but incidentally revealed a moderate right-sided pneumothorax, which was confirmed on chest radiograph ( Fig. 1 ). A transabdominal pelvic ultrasound performed during the same evaluation demonstrated a small amount of free fluid within the cul-de-sac but was otherwise unremarkable, without evidence of adnexal masses or definitive endometriotic lesions. She was managed with chest tube drainage but failed multiple clamping trials and subsequently underwent video-assisted thoracoscopic surgery (VATS). Several suspected blebs at the right upper lobe apex and inferolateral margin were resected and sent for pathology. A subtotal pleurectomy was also performed. Pathology demonstrated only inflammatory changes consistent with prior spontaneous pneumothorax but no specific pathology. No laparoscopic evaluation for pelvic endometriosis was performed. The postoperative course was uneventful, and she was discharged in stable condition. Fig. 1 (A) Right-sided pneumothorax on CT abdomen and pelvis during initial presentation. (B) Chest radiograph confirming pneumothorax. Fig. 1 (A) Right-sided pneumothorax on CT abdomen and pelvis during initial presentation. (B) Chest radiograph confirming pneumothorax. Two weeks later, the patient returned with an abnormal sensation of movement within the right chest, described as if the lung was shifting, along with mild, brief dyspnea. Oxygen saturation remained 100% on room air. Chest radiograph again confirmed a recurrent right-sided pneumothorax. A chest tube was inserted; however, a persistent air leak prompted hematology–oncology consultation, and chemical pleurodesis was subsequently performed with bleomycin and doxycycline. At this time, gynecology was also consulted given the suspicion for catamenial pneumothorax, and hormonal treatment with combined oral contraceptive (COC) was initiated. Cancer antigen 125 (CA-125) was elevated at 104. Despite pleurodesis and COC therapy, a right apical pneumothorax persisted for six days, requiring placement of a second chest tube by interventional radiology. After ten days of chest tube management, radiographic resolution was achieved, both chest tubes were removed, and the patient was discharged home in stable condition. Two weeks after her previous discharge, the patient returned to the ED with pleuritic chest pain and dyspnea in the setting of influenza infection, while her oxygen saturation remained normal. Chest radiograph revealed a recurrent moderate size right-sided pneumothorax. A second VATS was performed, during which both the lung and diaphragm were carefully inspected. No diaphragmatic fenestrations or endometriotic lesions were identified, but three new blebs were noted—one on the lateral right upper lobe and two on the medial right lower lobe—and resected. Adhesions likely from prior intervention between the right lower lobe and diaphragm were also dissected. Pathology showed no morphologic features of lymphangioleiomyomatosis, and immunohistochemical stains for estrogen (ER) and progesterone (PR) receptors were negative. During this admission, patient reported lighter but persistent bleeding since onset of COC, prompting a switch from low to moderate level regimen. After a three-week admission, she was discharged with a chest tube, which was removed one week later following radiographic resolution. At gynecologic follow-up, she reported complete cessation of menses and has since remained recurrence-free for six months.

Alberto Pedraza: Writing – review & editing, Writing – original draft. Qian Yang: Writing – review & editing, Writing – original draft. Nicholas Clayton: Writing – review & editing, Writing – original draft. Oleg Opsha: Supervision.

Catamenial pneumothorax, though classically seen in women aged 25–40 years, can occur even in adolescents and is easily mistaken for primary spontaneous pneumothorax. A detailed menstrual history is critical, as the temporal association with menses may be the only diagnostic clue. Sustained remission after complete menstrual suppression further supports a clinical diagnosis when pathology is inconclusive, emphasizing the importance of multidisciplinary management in this age group.

Catamenial pneumothorax (CP) is a spontaneous, recurrent pneumothorax that occurs in temporal association with menstruation, most commonly affecting the right hemithorax [ 9 ]. CP is a well-recognized manifestation of thoracic endometriosis, most often described in women between 30 and 40 years of age. Reports in adolescents are exceedingly rare, with “juvenile CP” generally defined as occurring in patients ≤19 years [ 6 ]. Our patient, aged 14, represents one of the youngest documented cases, underscoring the need to consider CP even in early adolescence. Diagnosis in this age group can be particularly challenging because primary spontaneous pneumothorax (PSP) remains statistically far more common—especially in adolescent males, but it can also affect otherwise healthy young females. The true incidence of CP may be underestimated, as many cases are initially misclassified as PSP. Adding to the difficulty, histopathologic confirmation is limited: only 40-50% of CP cases demonstrate thoracic endometriosis or ER/PR positivity, leaving most diagnoses to be made on clinical rather than pathological grounds [ 2 , 10 ]. CP is classically defined by symptom onset within 72 hours of menstruation [ 4 , 10 , 11 ]. However, this temporal association can be obscured by cycle irregularity, stress, or the initiation of hormonal therapy [ 4 ]. In our patient, three consecutive episodes occurred in proximity to menses, albeit not strictly within the 72-h window. Sustained remission following complete menstrual suppression provided strong support for the clinical diagnosis. Prior studies have demonstrated that thoracic endometriosis is identified far more frequently in catamenial pneumothorax than in non-catamenial spontaneous pneumothorax, indicating that menstrual temporal association serves as an important clinical indicator of underlying endometriosis when histopathologic confirmation is lacking [ 3 ]. This highlights the importance of obtaining a menstrual history in young female patients with recurrent or unexplained pneumothorax and involving gynecology early in the diagnostic process. Certain clinical and operative features may further distinguish CP from PSP. PSP typically presents with apical blebs and acute symptoms due to sudden alveolar rupture [ 8 ]. By contrast, CP may show basal or diaphragmatic lesions such as fenestrations, nodules, or pleural implants, and its hormonally mediated mechanisms often lead to gradual intrapleural air leaks [ 4 , 12 , 13 ]. These features may explain why CP can present with disproportionately mild or absent respiratory distress despite radiographic pneumothorax, as in our patient. Although diaphragmatic fenestrations were not identified, the presence of atypically distributed blebs raised suspicion. In addition, CA-125, though nonspecific, may serve as a supportive marker, reflecting endometriosis-related inflammation. Management of CP requires both surgery and hormonal treatment. Surgical approaches such as blebectomy, pleurectomy, or diaphragmatic repair alone carry recurrence rates of 20–30%, likely due to residual diaphragmatic defects or hormonally active lesions [ 11 ]. Multiple series have demonstrated that the combination of surgery with hormonal therapy yields superior long-term outcomes, particularly when complete menstrual suppression is achieved [ 14 , 15 ]. Because standardized treatment protocols specific to catamenial pneumothorax are lacking, medical management is largely extrapolated from established therapies for endometriosis. Hormonal treatment aims to suppress estrogen-dependent ectopic endometrial activity and broadly include ovulation suppression with COC or progestin-based regimens, as well as more profound ovarian suppression achieved through gonadotropin-releasing hormone (GnRH) analogs [ 16 ]. COCs primarily reduce cyclic hormonal fluctuations and inhibit ovulation, resulting in relatively mild suppression of endogenous estrogen production, whereas GnRH agonists induce a hypogonadotropic hypogonadal state through pituitary receptor downregulation, producing near-complete ovarian suppression and a reversible medical menopausal state [ 15 ]. Current evidence does not demonstrate clear superiority between cyclic and continuous hormonal regimens, and treatment is therefore typically individualized according to patient characteristics and therapeutic response [ 17 ]. In our patient, switching from a low-dose to a moderate-dose combined oral contraceptive induced amenorrhea and six months of remission, emphasizing the importance of adequate hormonal suppression. In adolescents, treatment must also account for long-term considerations, including fertility, bone health, and quality of life. Particularly for those under 16 years of age, GnRH agonist therapy is often reserved for refractory cases because profound hypoestrogenism may interfere with peak bone mass accrual during a critical period of skeletal development, making COC therapy the preferred initial approach [ 16 ]. Multidisciplinary collaboration between thoracic surgeons, gynecologists, and pediatric specialists is therefore essential to optimize outcomes.

Catamenial pneumothorax (CP) is an uncommon but important cause of spontaneous pneumothorax, occurring almost exclusively in women of reproductive age. It is most strongly linked to thoracic endometriosis, in which ectopic endometrial tissue involves the pleura, diaphragm, or, less frequently, the lung parenchyma. CP typically develops within 72 hours of menstruation and is characteristically right-sided and recurrent [ [1] , [2] , [3] ]. While most cases are reported in women aged 30–40 years, CP is exceedingly rare in the juvenile population, with only a small number of cases described in patients under 18 years of age [ 4 ]. Reports by Inoue et al. and Kramer et al. have highlighted the scarcity of cases in adolescents, underscoring the importance of documenting presentations in this age group [ 5 , 6 ]. Primary spontaneous pneumothorax (PSP) is substantially more common than catamenial pneumothorax in adolescents; pediatric estimates are ∼3.4 per 100,000 overall, with sex-specific rates of ∼1-2 per 100,000 in girls per year [ 7 ]. PSP is often associated with apical blebs or bullae on imaging and typically presents acutely with pleuritic chest pain and dyspnea [ 8 ]. By contrast, CP cases in the literature frequently report milder or more gradual onset of symptoms, possibly reflecting hormonally mediated air leaks rather than abrupt alveolar wall rupture [ 9 ]. Although direct comparative data are limited, such differences may help distinguish CP from PSP in clinical practice. This relative lack of severe symptoms may delay recognition of CP unless clinicians specifically inquire about menstrual timing and recurrence. Here, we present the case of a 14-year-old girl with recurrent right-sided pneumothorax, ultimately diagnosed as catamenial pneumothorax.

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.