Postoperative hormonal therapies reduce the recurrence of thoracic endometriosis-related pneumothorax.

OBJECTIVES: Thoracic endometriosis-related pneumothorax (TERP) frequently recurs even after surgery. Meanwhile, postoperative hormonal therapies (HTx) are believed to be effective for pelvic endometriosis. Therefore, we evaluated the relationship between postoperative TERP recurrence and postoperative HTx in a retrospective observational study. METHODS: We retrospectively reviewed the data of patients with TERP who underwent the first video-assisted thoracoscopic surgery between January 2011 and February 2022. RESULTS: Of the 248 patients eligible for this study, 67 (27.0%) experienced postoperative TERP recurrence. Postoperative HTx were administered to 70 patients (28.2%). Dienogest was the most frequently administered drug, given to 56.7% of patients. Following univariable analysis, postoperative hormonal therapies was closely related to reduce postoperative recurrence (P = 0.003). Likewise, the multivariable analysis revealed postoperative hormonal therapies were significantly associated with the risk reduction of recurrence (hazard ratio 0.28, P < 0.001). CONCLUSIONS: Postoperative HTx reduced TERP recurrence. We hypothesize that HTx may control residual endometrial tissues to avoid TERP if pleural endometrial tissues are resected as much as possible.

Clinicopathological Impacts of Expression of Neuronal Markers in Lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a tuberous sclerosis complex (TSC)-associated tumor, characterized by the expression of neural crest lineages including neuronal markers. Neural crest cells can differentiate into multiple cell types that contribute to tissues associated with TSC-related tumors, and TSC-related tumors could be specifically associated with distinct neural crest subtypes. This study aimed to clarify the clinicopathological effects of expression of neuronal markers in LAM. Lung tissues from 40 patients with LAM (of whom 13, 1, and 26 had undergone lung transplantation, lobectomy, and partial lung resection, respectively) were immunohistochemically analyzed. All patients were women, and their median age was 36 years (range: 24-62 y). All patients who underwent lung transplantation or lobectomy were classified as LAM histologic score (LHS)-3, whereas those who underwent partial lung resection were classified as LHS-1. LAM cells expressed peripherin (65%), and neuron-specific ßIII-tubulin (43%). A comparison of the early (LHS-1) and advanced (LHS-3) stages of LAM revealed that neuron-specific ßIII-tubulin was significantly expressed in the early stage of LAM ( P = 0.0009). Neuron-specific ßIII-tubulin-positive LAM was associated with younger age ( P < 0.0001), the coexistence of renal angiomyolipoma ( P = 0.027), and the absence of retroperitoneal LAM ( P = 0.045). Furthermore, based on the expression levels of immunohistochemical markers in LAM, 2 distinct clusters with different expression levels of neuronal markers were observed. Approximately 40% to 60% of patients with LAM expressed neuron-specific ßIII-tubulin and peripherin. Neuronal expression may be associated with disease severity.

Clinical and genetic features of 334 Asian patients with Birt-Hogg-Dubé syndrome (BHDS) who presented with pulmonary cysts with or without a history of pneumothorax, with special reference to BHDS-associated pneumothorax.

BACKGROUND: The clinical pulmonary manifestations and genetic features of Birt-Hogg-Dubé syndrome (BHDS) in Asian patients remained unclear. We aimed to clarify the clinical features of BHDS-associated pneumothorax (PTX) and retrospectively investigate potential contributing factors in the largest Asian cohort to date. METHODS: We reviewed the clinical and genetic data collected in 2006-2017, from the BHDS patients who were Asian and presented with pulmonary cysts with or without a history of PTX. RESULTS: Data from 334 (41.3% males; 58.7% females) patients from 297 unrelated families were reviewed. Among them, 314 (94.0%) patients developed PTX. The median age at the first occurrence of PTX was 32 years, which was significantly lower in males (P = 0.003) and patients without notable skin manifestations (P < 0.001). Seventy-six (24.2%) patients experienced their first PTX episode before the age of 25 years. PTX simultaneously occurred in the bilateral lungs of 37 (11.8%) patients. Among 149 patients who had their first PTX episode at least 10 years before BHDS diagnosis, PTX occurred more frequently in males (P = 0.030) and light smokers than in nonsmokers (P = 0.014). The occurrence of PTX peaked in the early 30s and gradually decreased with age but remained high in females (P = 0.001). We identified 70 unique FLCN germline variants, including duplications (46.4%), substitutions (7.1%), insertions/deletions (30.0%), and variants affecting splicing (12.5%). Approximately 80% of Asian patients suspected of having BHDS could be genetically diagnosed by examining FLCN exons 7, 9, 11, 12, and 13. No apparent genotype-phenotype correlation regarding pulmonary manifestations was identified. CONCLUSIONS: Our findings indicate that sex, smoking history, and skin manifestations at BHDS diagnosis significantly influence the clinical features of BHDS-associated PTX. These findings may contribute to the appropriate management and treatment of BHDS-associated PTX.

Dynamics of thoracic endometriosis in the pleural cavity.

BACKGROUND: Thoracic endometriosis-related pneumothorax is a secondary spontaneous pneumothorax caused by thoracic endometriosis. Diaphragmatic endometriosis is well-studied, but visceral and/or parietal pleural lesions are not. Although surgery is an effective treatment, postoperative recurrence rates are unsatisfactory probably due to inadequate understanding of underlying pathophysiology. We aimed to clarify the clinicopathological features of thoracic endometriosis. METHODS: In total, 160 patients who underwent thoracoscopic surgery from a single institution with histopathologically proven thoracic endometriosis from January 2015 to December 2019 were included. Clinicopathological characteristics and surgical outcomes were assessed retrospectively. RESULTS: The cohort median age was 41 (range 22-53) years. Pneumothorax was right-sided in 159 (99.4%) and left-sided in only 1 (0.6%) case. Visceral and parietal pleural lesions were diagnosed in 79 (49.4%) and 71 (44.4%) patients, respectively. In total, 104 visceral pleural lesions and 101 parietal pleural lesions were detected. The S4 region and the dorsal 6th intercostal space contained the largest number of visceral pleural (66 lesions) and parietal pleural lesions (25 lesions), respectively. Histopathological evaluation revealed endometriotic tissues, existing in the outer external elastic layer in all lesions, were localized or invaded deeply. The median follow-up period was 370 (range, 6-1824) days. The Kaplan-Meier method revealed that the 1- and 2-year postoperative recurrence rates were 13.8% and 19.3%, respectively. CONCLUSIONS: Visceral pleural endometriotic lesions may be disseminated from the visceral pleural surface and infiltrate into the pleura. Intraoperatively, careful observation of the specific sites, such as the visceral pleura of S4 and the parietal pleura of 6th intercostal space, is important to reduce postoperative recurrence.

Seventh BHD international symposium: recent scientific and clinical advancement.

The 7th Birt-Hogg-Dubé (BHD) International Symposium convened virtually in October 2021. The meeting attracted more than 200 participants internationally and highlighted recent findings in a variety of areas, including genetic insight and molecular understanding of BHD syndrome, structure and function of the tumor suppressor Folliculin (FLCN), therapeutic and clinical advances as well as patients' experiences living with this malady.

Current opinion and comparison of surgical procedures for the treatment of primary spontaneous pneumothorax.

INTRODUCTION: Although three-port video-assisted thoracoscopic surgery (VATS) is the standard radical treatment for primary spontaneous pneumothorax (PSP), several issues need to be addressed as the postoperative recurrence rate remains relatively high. Although bullectomy is effective in preventing the postoperative recurrence of PSP, recurrent pneumothorax often occurs, requiring additional methods such as pleural covering with absorbable mesh sheets, surgical chemical pleurodesis, pleural abrasion, or pleurectomy. In addition, minimally invasive approaches that exceed three-port VATS are required according to the social demand. These approaches, such as uniportal VATS, reduced port surgery, and needlescopic surgery, have cosmetic merits, lower postoperative pain, and similar surgical results as three-port VATS. AREAS COVERED: We focused on conventional and novel treatments for PSP in this article. EXPERT OPINION: Effective methods that prevent postoperative recurrence and minimally invasive approaches will become popular in the near future.

Folliculin haploinsufficiency causes cellular dysfunction of pleural mesothelial cells.

Birt-Hogg-Dubé syndrome (BHDS), an autosomal dominant inheritance disease caused by folliculin (FLCN) mutations, is associated with lung cysts and spontaneous pneumothorax. The possibility of FLCN haploinsufficiency in pleural mesothelial cells (PMCs) contributing to development of pneumothorax has not yet been clarified. Electron microscopy revealed exposed intercellular boundaries between PMCs on visceral pleura and decreased electron density around the adherens junctions in BHDS. To characterize cellular function of PMCs in BHDS patients (BHDS-PMCs), during surgery for pneumothorax, we established the flow cytometry-based methods of isolating high-purity PMCs from pleural lavage fluid. BHDS-PMCs showed impaired cell attachment and a significant decrease in proliferation and migration, but a significant increase in apoptosis compared with PMCs from primary spontaneous pneumothorax (PSP) patients (PSP-PMCs). Microarray analysis using isolated PMCs revealed a significant alteration in the expression of genes belonging to Gene Ontology terms "cell-cell adhesion junction" and "cell adhesion molecule binding". Gene set enrichment analysis demonstrated that CDH1, encoding E-cadherin, was identified in the down-regulated leading edge of a plot in BHDS-PMCs. AMPK and LKB1 activation were significantly impaired in BHDS-PMCs compared with PSP-PMCs. Our findings indicate that FLCN haploinsufficiency may affect the E-cadherin-LKB1-AMPK axis and lead to abnormal cellular function in BHDS-PMCs.

Isolation and characterisation of lymphatic endothelial cells from lung tissues affected by lymphangioleiomyomatosis.

Lymphangioleiomyomatosis (LAM) is a rare pulmonary disease characterised by the proliferation of smooth muscle-like cells (LAM cells), and an abundance of lymphatic vessels in LAM lesions. Studies reported that vascular endothelial growth factor-D (VEGF-D) secreted by LAM cells contributes to LAM-associated lymphangiogenesis, however, the precise mechanisms of lymphangiogenesis and characteristics of lymphatic endothelial cells (LECs) in LAM lesions have not yet been elucidated. In this study, human primary-cultured LECs were obtained both from LAM-affected lung tissues (LAM-LECs) and normal lung tissues (control LECs) using fluorescence-activated cell sorting (FACS). We found that LAM-LECs had significantly higher ability of proliferation and migration compared to control LECs. VEGF-D significantly promoted migration of LECs but not proliferation of LECs in vitro. cDNA microarray and FACS analysis revealed the expression of vascular endothelial growth factor receptor (VEGFR)-3 and integrin α9 were elevated in LAM-LECs. Inhibition of VEGFR-3 suppressed proliferation and migration of LECs, and blockade of integrin α9 reduced VEGF-D-induced migration of LECs. Our data uncovered the distinct features of LAM-associated LECs, increased proliferation and migration, which may be due to higher expression of VEGFR-3 and integrin α9. Furthermore, we also found VEGF-D/VEGFR-3 and VEGF-D/ integrin α9 signaling play an important role in LAM-associated lymphangiogenesis.

The effects of total pleural covering on pneumothorax recurrence and pulmonary function in lymphangioleiomyomatosis patients without history of pleurodesis or thoracic surgeries for pneumothorax.

BACKGROUND: Total pleural covering (TPC) is an innovative surgical procedure in which the entire visceral pleura is wrapped with sheets of oxidized regenerated cellulose (ORC) mesh under video-assisted thoracoscopic surgery. We have previously reported that TPC could successfully prevent pneumothorax recurrence in patients with lymphangioleiomyomatosis (LAM). However, the actual efficacy and preventive effect of TPC on pneumothorax recurrence remains unclear as many LAM patients already had pleural adhesion prior to TPC that was induced by thoracic surgery and/or pleurodesis. The purpose of this study is to evaluate the effects of TPC on pneumothorax recurrence and pulmonary function in LAM patients with no history of thoracic surgeries or pleurodesis. METHODS: We retrospectively reviewed medical charts of 52 patients (60 hemithoraces) who underwent TPC at our center, from January 2003 to September 2019, as a first surgical intervention for pneumothorax. RESULTS: Pneumothorax recurrence occurred in 12 patients [14 of 60 hemithoraces (23.3%)] during the observation period [27 months (14.7; 56.4) = median (lower; upper quartiles)]. The probability of recurrence-free hemithorax post TPC was 81.1% at 2.5 years and 64.1% at 5 years. TPC did not produce a significant decrease in either VC %predicted (pred) or FEV1/FVC. The pre- vs. post-TPC median (lower; upper quartiles) VC %pred was 85.7% (79.7; 98.0) vs. 87.2% (72.3; 95.6), P=0.535 and the FEV1/FVC was 84.6% (75.7; 89.6) vs. 83.0% (71.8; 87.0), P=0.667. Mechanistic/mammalian target of rapamycin (mTOR) inhibitors (mTORI) were subsequently initiated in 19 patients (36.5%) because of the progression of LAM. The postoperative FEV1%pred was significantly lower in patients who required mTORI than in those who did not [68.1% (57.3; 82.9) vs. 88.7% (84.6; 89.8), P=0.020]; the decline rate in FEV1%pred/year from pre to post TPC was significantly greater in LAM patients who required mTORI than in those who did not [-9.37% (-4.73; 12.9) vs. -1.94% (1.52; -4.50), P=0.029]. Postoperative complications were found in 25 of 52 hemithoraces (48.1%). CONCLUSIONS: TPC can prevent pneumothorax recurrence without causing ventilatory impairment or severe pleural symphysis in LAM patients. TPC is an effective treatment option for LAM-associated pneumothorax based on its efficacy and safety.

National survey of bladder endometriosis cases in Japan.

AIM: We aimed to describe the clinical presentation, operative or medical management, and postoperative recurrence of bladder endometriosis (BE). METHODS: We conducted a national survey to investigate BE cases from 2006 to 2016 in Japan. Histologically diagnosed cases were extracted and then investigated for the following factors: age at diagnosis, body mass index, symptoms, imaging modalities, surgical therapy, hormonal therapy, follow-up period, and postoperative recurrence. RESULTS: Eighty-nine patients with pathologically benign BE were identified. Eighty patients underwent surgery, whereas nine did not. Moreover, 34 and 44 patients underwent transurethral resection (TUR) and partial cystectomy (PC), respectively. Cumulative recurrence rates were significantly higher with TUR than with PC (p < 0.05). The recurrence rate tended to be higher after laparoscopic PC (n = 24) than after open PC (n = 20), but the difference was not statistically significant (p = 0.0879). Of the nine nonsurgical patients, eight received hormonal therapy and one did not. Efficacy rates of dienogest, GnRH agonist, and OC were 85.7%, 66.7%, and 66.7%, respectively. Of five patients with BE extending to the ureter or ureteral orifices, two underwent PC and ureteroneocystostomy and one underwent total nephroureterectomy due to renal function loss. CONCLUSION: To our knowledge, this is the first study to compare the postoperative recurrence of BE after TUR and PC. We found that cumulative recurrence rate is significantly lower after PC than after TUR. BE extending to the ureter or ureteral orifices is a very challenging condition. Further studies are required for the optimal management of BE.

Is conventional management of primary spontaneous pneumothorax appropriate?

OBJECTIVE: This study aimed to evaluate the recurrence rate after primary and secondary conservative treatments and to clarify the validity of current primary spontaneous pneumothorax management by comparing secondary conservative treatment and surgical outcomes. METHODS: Data from 166 patients with primary spontaneous pneumothorax treated at a single site between September 2015 and March 2019 were retrospectively evaluated. Patient characteristics of those who received primary conservative therapy (n = 166) and secondary conservative therapy (n = 28) were summarized. The outcomes from patients who experienced recurrence (n = 64) were compared based on those who underwent surgery (n = 24) and those who underwent secondary conservative therapy (n = 28). RESULTS: The post-treatment day 60 recurrence rate was 27.1 and 49.5% cases in the primary and secondary treatment groups, respectively, which was significantly higher after secondary treatment than after primary treatment with conservative therapy (p = 0.032). The post-treatment one-year recurrence rate was 13.5 and 57.9% in patients who underwent surgery and secondary conservative treatment, respectively; secondary conservative treatment resulted in a significantly higher recurrence rate than surgery (p < 0.001). CONCLUSIONS: There is evidence for guidelines that recommend surgery for recurrent primary spontaneous pneumothorax after primary conservative therapy based on its lower and more delayed post-treatment recurrence rate than secondary treatment with conservative therapy.

Clinical practice guidelines for the treatment of extragenital endometriosis in Japan, 2018.

The aim of this publication is to disseminate the clinical practice guidelines for the treatment of intestinal, bladder/ureteral, thoracic and umbilical endometriosis, already published in Japanese, to non-Japanese speakers. For developing the original Japanese guidelines, the clinical practice guideline committee was formed by the research team for extragenital endometriosis, which is part of the research program of intractable disease of the Japanese Ministry of Health, Labor and Welfare. The clinical practice guideline committee formulated eight clinical questions for the treatment of extragenital endometriosis, which were intestinal, bladder/ureteral, thoracic and umbilical endometriosis. The committee performed a systematic review of the literature to provide responses to clinical questions and developed clinical guidelines for extragenital endometriosis, according to the process proposed by the Medical Information Network Distribution Service. The recommendation level was determined using modified Delphi methods. The clinical practice guidelines were officially approved by the Japan Society of Obstetrics and Gynecology and the Japan Society of Endometriosis. This English version was translated from the Japanese version.

IFITM1 is a Novel, Highly Sensitive Marker for Endometriotic Stromal Cells in Ovarian and Extragenital Endometriosis.

When the presence of endometriotic lesions are not evident by hematoxylin and eosin staining, CD10 is used to highlight and confirm the presence of endometriotic stroma. However, CD10 is not specific only to the endometrial stroma but is also expressed in many other cells. Recently, interferon-inducible transmembrane protein 1 (IFITM1) was reported as a highly specific immunohistochemical marker of normal endometrial stroma and endometrial stromal neoplasm. In this study, we examined the expression of IFITM1 and CD10 in 18 cases of ovarian endometriosis and 44 cases of extragenital endometriosis. Among the 62 patients, 62 (100.0%) were positive for IFITM1 and 60 (96.8%) for CD10, and CD10 was negative in 2 cases that were positive for IFITM1. Additionally, we found that IFITM1 sensitivity was unaffected by the presence or absence of hormonal therapy. To the best of our knowledge, this represents the first demonstration of IFITM1 as a highly sensitive stromal marker of ovarian and extragenital endometriosis.

PAX8: A Highly Sensitive Marker for the Glands in Extragenital Endometriosis.

In cases of extragenital endometriosis or microscopic endometriosis lesions, pathological diagnosis can be challenging because endometriotic stroma and glands represent only a minor component of fibrotic endometriotic lesions. For better accuracy of diagnosis, the development of a sensitive and specific epithelial marker is beneficial. Previous studies showed that PAX8 is a highly sensitive and specific marker for primary and metastatic Mullerian epithelial tumors. Therefore, we sought to examine whether PAX8 is a highly sensitive marker for glands in extragenital endometriosis. Eight and 47 samples of ovarian endometrioma and extragenital endometriosis, respectively, were evaluated in this study. We calculated the percentage of samples positively immunostained for PAX8, CD10, estrogen receptor (ER), and progesterone receptor (PR). PAX8 was positive for endometriotic epithelial cells in 95.7% (45/47) of extragenital endometrioses and in 100% (8/8) of ovarian endometrioses. CD10 was positive for endometriotic stromal cells in 97.9% (46/47) of extragenital endometrioses. PAX8 was strongly positive for glands, even in a CD10-negative case. The expression of PAX8, CD10, and PR was not affected by preoperative hormonal therapy, and the positive rate of ER staining was significantly reduced by preoperative hormonal therapy. In conclusion, PAX8 is a highly sensitive epithelial marker for extragenital endometriosis. This specific expression was maintained under hormonal therapy. It is noteworthy that extragenital endometriosis maintains the expression of this lineage marker, although it occurs at various sites, and its cause and mechanism of development might be different. PAX8 nuclear expression can be useful in detecting extragenital endometriosis in clinical practice.

Does a gender have something to do with clinical pictures of primary spontaneous pneumothorax?

OBJECTIVE: Primary spontaneous pneumothorax is relatively rarer in women than in men. In addition, women develop secondary spontaneous pneumothorax, such as lymphangioleiomyomatosis, which is rare and difficult to diagnose. Therefore, the clinical characteristics of primary spontaneous pneumothorax in women remain unknown presently. We compared the clinical characteristics of primary spontaneous pneumothorax between the two sexes at two pneumothorax centers. METHODS: Between January 2015 and July 2019, we retrospectively evaluated 627 cases (106 women and 521 men) who underwent first video-assisted thoracoscopic surgery for primary spontaneous pneumothorax and extracted the medical backgrounds and postoperative recurrence between the sexes. Univariate and multivariate analysis was used to examine the effect of sexual specificity on postoperative recurrence. RESULTS: Among women and men with PSP, the mean ages were 27.8 ± 10.7 and 24.3 ± 10.0 years, respectively; their mean heights were 162.0 ± 5.9 and 173.3 ± 6.1 cm, respectively. These differences were statistically significant. Three women (2.8%) and 54 men (10.4%) developed postoperative recurrence, which showed significant difference on Kaplan-Meier analysis (p = 0.027). Univariate and multivariate analysis showed the factors; women (p = 0.045, hazard ratio: 0.289 [95% confidence interval 0.086-0.973]) and smoker (p = 0.035, hazard ratio: 0.269 [95% confidence interval 0.079-0.909]) had the preventing factor for postoperative recurrence, respectively. CONCLUSIONS: Women with PSP had lower postoperative recurrence rate than men. Although we could not reveal why women had lower postoperative recurrence rates than men in this study, the sexual difference such as hormonal cycle, development of body structure possibly affects the clinical characteristics of women with primary spontaneous pneumothorax.

A National Survey of Umbilical Endometriosis in Japan.

STUDY OBJECTIVE: To identify the clinical presentation, diagnostic evaluation, operative or medical management, and postoperative recurrence of umbilical endometriosis. DESIGN: A retrospective national survey. SETTING: Obstetrics and Gynecology and Plastic Surgery Departments at a teaching hospital in Japan. PATIENTS: Patients with umbilical endometriosis or malignant transformation. INTERVENTIONS: A national survey was conducted to identify and evaluate cases of umbilical endometriosis or malignant transformation documented between 2006 and 2016. MEASUREMENTS AND MAIN RESULTS: The following were evaluated for each patient: age at diagnosis, body mass index, medical history, presence of extragenital endometriosis, surgical history, symptoms, imaging modalities, surgical therapy, hormonal therapy, follow-up period, postoperative recurrence, and time to recurrence. Ninety-six patients were identified with pathologically diagnosed benign umbilical endometriosis. The patients frequently had swelling (86.5%), pain (81.3%), or bleeding (44.8%) in the umbilicus. Sensitivity was 87.1% for physical examination, 76.5% for transabdominal ultrasonography, 75.6% for computed tomography, and 81.8% for magnetic resonance imaging. The cumulative recurrence rate was 1.34% at 6 months, 6.35% at 12 months, and 6.35% at 60 months after surgery. Importantly, there was no recurrence after wide resection including of the peritoneum (0 of 37 cases). The efficacy of dienogest (an oral progestin), gonadotropin-releasing hormone agonists, and oral contraceptives was 91.7%, 81.8%, and 57.1%, respectively. Finally, 2 cases of malignant transformation were identified. CONCLUSION: There was a low recurrence rate following surgery, and hormonal treatment is an option, although the current findings suggest surgical therapy as the first choice of treatment for umbilical endometriosis.

A novel dual-covering method in video-assisted thoracic surgery for pediatric primary spontaneous pneumothorax.

BACKGROUND: Primary spontaneous pneumothorax (PSP) generally occurs in young adults, whereas pediatric PSP is uncommon. It is difficult to source reliable data on pediatric PSP, the management of which is based on guidelines for adult PSP; however, the rate of recurrence after video-assisted thoracoscopic surgery (VATS) for pediatric PSP is reported to be higher. METHODS: We reviewed retrospectively a collective total of 66 surgical cases of a first pneumothorax episode in 46 children under 16 years of age, who were treated at our hospital between February, 2005 and November, 2017. RESULTS: The surgical cases were divided into two groups, depending on how the treated lesions were covered. In the dual-covering (DC) group, the PSP was covered by oxidized regenerated cellulose and polyglycolic acid (8 patients; 13 cases) and in the single-covering (SC) group, the PSP was covered by oxidized regenerated cellulose (38 patients; 53 cases). There was no incidence of recurrence after surgery in the DC group, but 17 cases (32.1%) of recurrence after surgery in the SC group. This difference was significant. CONCLUSION: The DC method prevented the recurrence of PSP more effectively than the SC method after VATS in pediatric patients. Long-term follow-up after VATS for pediatric PSP is also important because of the risk of delayed recurrence.

IFITM1 is a Novel, Highly Sensitive Marker for Endometriotic Stromal Cells in Ovarian and Extragenital Endometriosis.

When the presence of endometriotic lesions are not evident by hematoxylin and eosin staining, CD10 is used to highlight and confirm the presence of endometriotic stroma. However, CD10 is not specific only to the endometrial stroma but is also expressed in many other cells. Recently, interferon-inducible transmembrane protein 1 (IFITM1) was reported as a highly specific immunohistochemical marker of normal endometrial stroma and endometrial stromal neoplasm. In this study, we examined the expression of IFITM1 and CD10 in 18 cases of ovarian endometriosis and 44 cases of extragenital endometriosis. Among the 62 patients, 62 (100.0%) were positive for IFITM1 and 60 (96.8%) for CD10, and CD10 was negative in 2 cases that were positive for IFITM1. Additionally, we found that IFITM1 sensitivity was unaffected by the presence or absence of hormonal therapy. To the best of our knowledge, this represents the first demonstration of IFITM1 as a highly sensitive stromal marker of ovarian and extragenital endometriosis.

PAX8: A Highly Sensitive Marker for the Glands in Extragenital Endometriosis.

In cases of extragenital endometriosis or microscopic endometriosis lesions, pathological diagnosis can be challenging because endometriotic stroma and glands represent only a minor component of fibrotic endometriotic lesions. For better accuracy of diagnosis, the development of a sensitive and specific epithelial marker is beneficial. Previous studies showed that PAX8 is a highly sensitive and specific marker for primary and metastatic Mullerian epithelial tumors. Therefore, we sought to examine whether PAX8 is a highly sensitive marker for glands in extragenital endometriosis. Eight and 47 samples of ovarian endometrioma and extragenital endometriosis, respectively, were evaluated in this study. We calculated the percentage of samples positively immunostained for PAX8, CD10, estrogen receptor (ER), and progesterone receptor (PR). PAX8 was positive for endometriotic epithelial cells in 95.7% (45/47) of extragenital endometrioses and in 100% (8/8) of ovarian endometrioses. CD10 was positive for endometriotic stromal cells in 97.9% (46/47) of extragenital endometrioses. PAX8 was strongly positive for glands, even in a CD10-negative case. The expression of PAX8, CD10, and PR was not affected by preoperative hormonal therapy, and the positive rate of ER staining was significantly reduced by preoperative hormonal therapy. In conclusion, PAX8 is a highly sensitive epithelial marker for extragenital endometriosis. This specific expression was maintained under hormonal therapy. It is noteworthy that extragenital endometriosis maintains the expression of this lineage marker, although it occurs at various sites, and its cause and mechanism of development might be different. PAX8 nuclear expression can be useful in detecting extragenital endometriosis in clinical practice.

A total pleural covering of absorbable cellulose mesh prevents pneumothorax recurrence in patients with Birt-Hogg-Dubé syndrome.

BACKGROUND: Birt-Hogg-Dubé syndrome (BHDS) is a recently recognized inherited multiple cystic lung disease causing recurrent pneumothoraces. Similarly to the lesions in patients with lymphangioleiomyomatosis (LAM), the pulmonary cysts are innumerable and widely dispersed and cannot all be removed. We recently described a total pleural covering (TPC) that covers the entire visceral pleura with oxidized regenerated cellulose (ORC) mesh. TPC successfully prevented the recurrence of pneumothorax in LAM patients. The purpose of this study was to evaluate the effect of an ORC pleural covering on pneumothorax recurrence in BHDS patients. RESULTS: This retrospective study enrolled a total of 81 pneumothorax patients with the diagnosis of BHDS who underwent 90 covering surgeries from January 2010 to August 2017 at Tamagawa Hospital. During the first half of the study period, a lower pleural covering (LPC) which covered the affected area with ORC mesh was mainly used to treat 38 pneumothoraces. During the second half of the study period, TPC was primarily performed for 52 pneumothoraces. All the thoracoscopic surgeries were successfully performed without serious complications (≥ Clavien-Dindo grade III). The median follow-up periods after LPC/TPC were 66/34 months, respectively. Pneumothorax recurrence rates after LPC at 2.5/5/7.5 years postoperatively were 5.4/12/42%, respectively; none of the patients who had underwent TPC developed postoperative pneumothorax recurrence (P = 0.032). CONCLUSIONS: TPC might be an effective option for surgical treatment of intractable pneumothorax in patients with BHDS.