Malignant Chest Wall Tumors: Complex Defects and Their Management-A Review of 181 Cases.

BACKGROUND: Chest wall tumors are a heterogeneous group of tumors that are managed by surgeons from diverse specialties. Due to their rarity, there is no consensus on their diagnosis and management. MATERIALS: This retrospective, descriptive analysis includes patients with malignant chest wall tumors undergoing chest wall resection. Tumors were classified as primary, secondary, and metastatic tumors. The analysis includes clinicopathological characteristics, resection-reconstruction profile, and relapse patterns. RESULTS: A total of 181 patients underwent chest wall resection between 1999 and 2020. In primary tumors (69%), the majority were soft tissue tumors (59%). In secondary tumors, the majority were from the breast (45%) and lung (42%). Twenty-five percent of patients received neoadjuvant chemotherapy, and 98% of patients underwent R0 resection. Soft tissue, skeletal + soft tissue, and extended resections were performed in 45%, 70%, and 28% of patients, respectively. The majority of patients (60%) underwent rib resections, and a median of 3.5 ribs were resected. The mean defect size was 24 cm2. Soft tissue reconstruction was performed in 40% of patients, mostly with latissimus dorsi flaps. Rigid reconstruction was performed in 57% of patients, and 18% underwent mesh-bone cement sandwich technique reconstruction. Adjuvant radiotherapy and chemotherapy were given to 29% and 39% of patients, respectively. CONCLUSIONS: This is one of the largest single-institutional experiences on malignant chest wall tumors. The results highlight varied tumor spectra and multimodality approaches for optimal functional and survival outcomes. In limited resource setting, surgery, including reconstructive expertise, is very crucial.

NUT carcinoma and thoracic SMARCA4-deficient undifferentiated tumour: facts and controversies.

NUT carcinoma and thoracic SMARCA4-deficient undifferentiated tumour are unique entities in the 5th edition of the World Health Organisation (WHO) Classification of Thoracic Tumours, whose definitions include molecular genetic abnormalities. These aggressive tumours require rapid work-ups on biopsies, but a broad list of differential diagnoses poses challenges for practising pathologists. This review provides an update on their key clinicopathological and molecular characteristics, as well as controversies regarding tumour classification and diagnostic strategy. Phenotypical assessment plays a substantial role in diagnosis because recurrent and predictable clinicopathological findings exist, including robust immunohistochemical phenotypes. Accurate diagnosis is crucial for appropriate management and a clearer understanding of the disease.

Complications of chest wall around malignant tumors: differences based on reconstruction strategy.

BACKGROUND: Malignant chest wall tumors need to be excised with wide resection to ensure tumor free margins, and the reconstruction method should be selected according to the depth and dimensions of the tumor. Vascularized tissue is needed to cover the superficial soft tissue defect or bone tissue defect. This study evaluated differences in complications according to reconstruction strategy. METHODS: Forty-five patients with 52 operations for resection of malignant tumors in the chest wall were retrospectively reviewed. Patients were categorized as having superficial tumors, comprising Group A with simple closure for small soft tissue defects and Group B with flap coverage for wide soft tissue defects, or deep tumors, comprising Group C with full-thickness resection with or without mesh reconstruction and Group D with full-thickness resection covered by flap with or without polymethyl methacrylate. Complications were evaluated for the 52 operations based on reconstruction strategy then risk factors for surgical and respiratory complications were elucidated. RESULTS: Total local recurrence-free survival rates in 45 patients who received first operation were 83.9% at 5 years and 70.6% at 10 years. The surgical complication rate was 11.5% (6/52), occurring only in cases with deep tumors, predominantly from Group D. Operations needing chest wall reconstruction (p = 0.0016) and flap transfer (p = 0.0112) were significantly associated with the incidence of complications. Operations involving complications showed significantly larger tumors, wider areas of bony chest wall resection and greater volumes of bleeding (p < 0.005). Flap transfer was the only significant predictor identified from multivariate analysis (OR: 10.8, 95%CI: 1.05-111; p = 0.0456). The respiratory complication rate was 13.5% (7/52), occurring with superficial and deep tumors, particularly Groups B and D. Flap transfer was significantly associated with the incidence of respiratory complications (p < 0.0005). Cases in the group with respiratory complications were older, more frequently had a history of smoking, had lower FEV1.0% and had a wider area of skin resected compared to cases in the group without respiratory complications (p < 0.05). Preoperative FEV1.0% was the only significant predictor identified from multivariate analysis (OR: 0.814, 95%CI: 0.693-0.957; p = 0.0126). CONCLUSIONS: Surgical complications were more frequent in Group D and after operations involving flap transfer. Severe preoperative FEV1.0% was associated with respiratory complications even in cases of superficial tumors with flap transfer.

Molecularly Defined Thoracic Neoplasms.

Molecularly defined neoplasms are increasingly recognized, given the broader application and performance of molecular studies. These studies allow us to better characterize these neoplasms and learn about their pathogenesis. In the thorax, molecularly defined neoplasms include tumors such as NUT carcinoma, SMARCA4-deficient undifferentiated tumor (DUT), primary pulmonary myxoid sarcoma with EWSR1::CREB1 fusion, hyalinizing clear cell carcinoma, and SMARCB1-deficient neoplasms. Overall, these tumors are rare but are now more often recognized given more widely available immunostains such as NUT (NUT carcinoma), BRG1 (SMARCA4-DUT), and INI-1 (SMARCB1-deficient neoplasm). Furthermore, cytogenetic studies for EWSR1 to support a hyalinizing clear cell carcinoma or primary pulmonary myxoid sarcoma are, in general, easily accessible. This enables pathologists to recognize and diagnose these tumors. The diagnosis of these tumors is important for clinical management and treatment. For instance, clinical trials are available for patients with NUT carcinoma, SMARCA4-DUT, and SMACRB1-deficient neoplasms. Herein, our current knowledge of clinical, morphologic, immunophenotypic, and molecular features of NUT carcinomas, SMARCA4-DUT, primary pulmonary myxoid sarcomas, hyalinizing clear cell carcinoma, and SMARCB1-deficient neoplasms will be reviewed.

Cuproptosis, the novel type of oxidation-induced cell death in thoracic cancers: can it enhance the success of immunotherapy?

Copper is an important metal micronutrient, required for the balanced growth and normal physiological functions of human organism. Copper-related toxicity and dysbalanced metabolism were associated with the disruption of intracellular respiration and the development of various diseases, including cancer. Notably, copper-induced cell death was defined as cuproptosis which was also observed in malignant cells, representing an attractive anti-cancer instrument. Excess of intracellular copper leads to the aggregation of lipoylation proteins and toxic stress, ultimately resulting in the activation of cell death. Differential expression of cuproptosis-related genes was detected in normal and malignant tissues. Cuproptosis-related genes were also linked to the regulation of oxidative stress, immune cell responses, and composition of tumor microenvironment. Activation of cuproptosis was associated with increased expression of redox-metabolism-regulating genes, such as ferredoxin 1 (FDX1), lipoic acid synthetase (LIAS), lipoyltransferase 1 (LIPT1), dihydrolipoamide dehydrogenase (DLD), drolipoamide S-acetyltransferase (DLAT), pyruvate dehydrogenase E1 subunit alpha 1 (PDHA1), and pyruvate dehydrogenase E1 subunit beta (PDHB)). Accordingly, copper-activated network was suggested as an attractive target in cancer therapy. Mechanisms of cuproptosis and regulation of cuproptosis-related genes in different cancers and tumor microenvironment are discussed in this study. The analysis of current findings indicates that therapeutic regulation of copper signaling, and activation of cuproptosis-related targets may provide an effective tool for the improvement of immunotherapy regimens.

The application of three-dimensional custom-made prostheses in chest wall reconstruction after oncologic sternal resection.

BACKGROUND AND OBJECTIVES: As one of the cutting-edge advances in the field of reconstruction, three-dimensional (3D) printing technology has been constantly being attempted to assist in the reconstruction of complicated large chest wall defects. However, there is little literature assessing the treatment outcomes of 3D printed prostheses for chest wall reconstruction. This study aimed to analyze the surgical outcomes of 3D custom-made prostheses for the reconstruction of oncologic sternal defects and to share our experience in the surgical management of these rare and complex cases. METHODS: We summarized the clinical features of the sternal tumor in our center, described the surgical techniques of the application of 3D customized prosthesis for chest wall reconstruction, and analyzed the perioperative characteristics, complications, overall survival (OS), and recurrence-free survival of patients. RESULTS: Thirty-two patients with the sternal tumor who underwent chest wall resection were identified, among which 13 patients used 3D custom-made titanium implants and 13 patients used titanium mesh for sternal reconstruction. 22 cases were malignant, and chondrosarcoma is the most common type. The mean age was 46.9 years, and 53% (17/32) of the patients were male. The average size of tumor was 6.4 cm, and the mean defect area was 76.4 cm2. 97% (31/32) patients received R0 resection. Complications were observed in 29% (9/32) of patients, of which wound infection (22%, 7/32) was the most common. The OS of the patients was 72% at 5 years. CONCLUSION: We demonstrated that with careful preoperative assessment, 3D customized prostheses could be a viable alternative for complex sternal reconstruction.

Outcomes of non-angiosarcoma radiation-associated soft tissue sarcomas of the chest.

BACKGROUND: Radiation-associated soft tissue sarcomas (RA-STS) are rare complications of patients receiving radiation therapy (RT) and are generally associated with a poor prognosis. Most of the literature surrounding RA-STS of the chest is centered on angiosarcoma. Therefore, we aim to document the management and outcome of patients with non-angiosarcoma RA-STS of the chest. METHODS: We reviewed 17 patients (all female, median age 65 years) diagnosed with RA-STS. The most common primary malignancy was breast carcinoma (n = 15), with a median RT dose of 57.9 Gy. All patients underwent surgical resection; five patients (29%) received radiotherapy; and five patients (29%) received peri-operative chemotherapy. RESULTS: The 5-year local recurrence and metastatic-free survival were 61% and 60%, while the 5-year disease-specific survival was 53%. Local recurrence was associated with death due to disease (HR 9.06, p = 0.01). Complications occurred in nine of patients, most commonly due to a wound complication (n = 7). At the most recent follow-up, the median Musculoskeletal Tumor Society Score was 63%. CONCLUSION: RA-STS involving the chest wall are aggressive tumors with a high risk of local relapse and death due to disease. Local recurrence was associated with death due to disease; as such, we recommend aggressive surgical management with evaluation for adjuvant therapies.

Thoracic SMARCA4-deficient undifferentiated tumor: current knowledge and future perspectives.

Thoracic SMARCA4-deficient undifferentiated tumor is a newly recognized disease entity characterized as a high-grade malignant neoplasm with an undifferentiated or rhabdoid phenotype. The tumor was initially identified as a subtype of thoracic sarcoma with SMARCA4 loss, but further investigation resulted in its classification as a subtype of epithelial malignancies in the current World Health Organization classification. SMARCA4-deficient undifferentiated tumor is highly aggressive and has a poor prognosis. Because of its rarity, an optimal treatment strategy has not yet been identified. In this review, we summarize the literature on SMARCA4-deficient undifferentiated tumor in terms of its clinical characteristics, diagnosis, treatment strategy and future perspectives.

Clinical characteristics and prognosis of patients with incidentally discovered chest wall sarcoma compared with those of symptomatic patients.

OBJECTIVE: Sarcomas of the bone and soft tissues are detected after the onset of pain, detectable mass and related symptoms in the absence of a standardized screening examination. However, primary chest wall sarcomas can be incidentally detected upon chest X-ray or computed tomography. Previous studies of incidental primary chest wall sarcomas lack prognosis and disease-specific clinical data. This study aimed to investigate the prognoses of patients with incidental chest wall sarcomas and compare them with those of symptomatic patients. METHODS: This study included 18 patients diagnosed with primary chest wall sarcoma between 2010 and 2023. Patient information such as age, sex, tumour diameter, tumour location, symptoms, treatment, time to treatment initiation, pathological diagnosis and outcome were retrospectively analysed. RESULTS: Among the 18 patients, the sarcomas were incidentally detected in five by chest X-ray and computed tomography in three and two patients, respectively. The pathological diagnoses of the patients were Ewing sarcoma, Chondrosarcoma grade 1, grade 2, periosteal osteosarcoma and malignant peripheral nerve sheath tumour. The patients had no symptoms at the first visit to our hospital, and no lesions in other organs were detected at the time of the initial examination. At the final follow-up, the patients remained disease-free after radical treatment. The tumour sizes of the five patients were significantly smaller than those of patients with symptoms (P = 0.003). CONCLUSIONS: The incidental detection of chest wall sarcomas and consequent early detection and treatment of tumours improves patient prognosis relative to that of symptomatically diagnosed patients.

A Novel NUTM1-NSMCE2 Fusion Gene in a Pediatric Chest NUT Carcinoma.

Nuclear protein of the testis carcinoma is an exceedingly rare and poorly differentiated carcinoma characterized by BDR4::NUTM1 gene translocation. Typically, the tumor affects young adults, and no standardized recommendations for therapeutic management have been available since 2022; the clinical course remains mostly dismal. We report the successful multimodal treatment of a 13-year-old boy affected by a primary chest NUT-carcinoma with a novel NUTM1 rearrangement that remains in complete continuous remission at 30 months from diagnosis.

A Single-center Experience of Radiotherapy in Pediatric Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Chest Wall.

AIM: To evaluate the treatment results, prognostic parameters, and treatment-related toxicity in patients with Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET) of the chest wall who underwent surgery, chemotherapy, and radiotherapy (RT) in a tertiary referral center. METHODS: The data of 24 patients under 18 years of age with a histologic diagnosis of ES/PNET in the chest wall that received RT in our department between February 2003 and July 2020 were retrospectively evaluated. RT was applied to the primary site±whole involved chest wall and to the whole lung in patients with lung metastasis. RESULTS: The median age was 8.5 years (range: 1.5 to 17 y), 15 (63%) patients were female and 9 were male (37%). The tumor localization was extrathoracic in 18 (75%) and intrathoracic in 6 (25%) patients. Mediastinal lymph node and distant metastasis (DM) was present in 5 (21%) and 4 (16%) cases at diagnosis, respectively. The median follow-up after RT was 47 months (range: 11 to 162 mo). The 2-year and 5-year overall survival, event-free survival, local recurrence-free survival, and pleural recurrence-free survival were 83% and 48%, 48% and 42%, 74% and 48%, and 61% and 52%, respectively. The overall local control rate was 83% and the pleural control rate was 67%. RT was well tolerated, with 1 case of grade 3 acute dermatitis and 1 case of grade 3 subacute radiation pneumonitis. Late toxicity was observed in 3 (13%) cases. CONCLUSION: Long-term survival can be achieved with extended-field RT even in patients with ES/PNET of the chest wall with DM. The low toxicity rates allow us to draw the conclusion that RT with modern techniques is an effective and safe treatment modality for these patients.

Discordance of retroperitoneal and thoracic histologic findings in patients with metastatic germ cell tumors at postchemotherapy residual tumor resection.

INTRODUCTION AND OBJECTIVES: Postchemotherapy residual tumor resection (PC-RTR) is an important part of the multimodal treatment for patients with metastatic germ cell tumors. Simultaneous retroperitoneal and thoracic metastases often require consecutive surgical procedures. This study analyzes the histologic findings after abdominal and thoracic surgery in order to tailor the sequence and intensity of surgery. PATIENTS AND METHODS: From a total of 671 PC-RTRs from 2008 to 2021 we analyzed 50 patients with stage III non-seminomatous germ cell tumor (NSGCT) who had undergone both retroperitoneal and thoracic postchemotherapy residual tumor resection after first-line and salvage chemotherapy. RESULTS: All patients included had stage III NSGCT. 39 and 11 patients received first-line and salvage chemotherapy, respectively. 45 (90%) patients received retroperitoneal resection first, followed by thoracic surgery. Three patients (6%) underwent thoracic surgery before retroperitoneal surgery and two patients (4%) underwent simultaneous surgery. Overall, the histology of retroperitoneal and thoracic specimens was discordant in 23% of cases. After first-line chemotherapy, of fourteen patients with necrosis in retroperitoneal histology, four patients had vital carcinoma in lung histology. In patients with teratoma in the retroperitoneum, the thoracic findings were concordant in most cases (78%). When teratomatous elements were also present in the orchiectomy specimen, concordance was 100%. After salvage chemotherapy, the discordance rate was 55%. CONCLUSION: The data presented in this study underline that retroperitoneal residual masses with necrosis cannot reliably predict histologic findings of thoracic specimens. Patients with teratoma in the retroperitoneum have a high likelihood of teratoma in the thoracic specimen.

Surgical resection of advanced intrathoracic tumors through a combination of the hemiclamshell and transmanubrial approaches.

PURPOSE: The hemiclamshell (HCS) approach provides a comprehensive view of the anterior mediastinum, whereas the transmanubrial osteomuscular sparing approach (TMA) allows sufficient exposure of the cervico-thoracic transition. We assessed the effectiveness and the outcomes of the combined HCS plus TMA approach to resect thoracic malignant tumors. METHODS: We reviewed five patients with thoracic malignant tumors invading the thoracic outlet who underwent surgery using an HCS and TMA approach between 2018 and 2021. RESULTS: The preoperative diagnosis was myxofibrosarcoma, lung cancer, thymic cancer, thymoma, and neurofibromatosis type1 in one patient each, respectively. Cardiovascular reconstruction was done on the aortic arch in two patients, on the descending aorta in one, and on the superior vena cava in one, combined with resection of the vagus nerve in three patients, of the phrenic nerve in two, and of vertebra in one, with overlap in some cases. The TMA was added because all patients required dissection of the periphery of the subclavian artery, and two had tumor extension to the neck. Macroscopic complete resection was achieved in four patients. There was no postoperative mortality. CONCLUSION: The combination of the HCS and TMA approaches at the same operation provides a comprehensive view of the mediastinum, lung, and cervico-thoracic transition and allows safe access to the thoracic great vessels and subclavian vessels.

Is extended resection for locally advanced thoracic cancer with cardiopulmonary bypass justified?

BACKGROUND: Resection of intrathoracic tumor with cardiopulmonary bypass (CPB) remains a relatively under-reported intervention in literature, and its role in managing locally advanced mediastinal and lung cancers is a topic of ongoing debate. Our aim was to review our experience and assess the role of CPB for treating locally advanced mediastinal and lung cancers. METHODS: Between 2015 and 2020, this study initially included 10 patients with primary locally advanced thoracic malignancies with apparent adjacent cardiovascular invasion demonstrated by thoracic imaging scans. Operation was performed based on a multidisciplinary tumor board consensus. Eventually, 8 patients (3 primary lung cancers and 5 mediastinal cancers) received either salvage or elective resection with CPB; two completed surgery without requiring CPB. RESULTS: Regarding the extent of adjacent structure involvement, 4 patients presented with involvement of the superior vena cava (SVC), 1 involved the right atrium (RA), 2 involved the SVC and RA, and 1 involved the SVC, the origin of main pulmonary artery, and the ascending aorta. Thirty-day mortality occurred in two of three patients receiving salvage surgery due to respiratory insufficiency. With the long-term follow-up, one patient died of recurrence 25 months postoperatively, one survived with recurrence 30 months postoperatively, and four were alive without recurrence for 35, 36, 49, and 107 months after operations. CONCLUSION: In certain patients, particularly for elective surgical candidates rather than salvage resection, CPB allows for extended resection of locally advanced thoracic cancers with acceptable perioperative safety and survival.

[Cytopathological characteristics of SMARCA4-deficient thoracic undifferentiated tumors in serous effusion].

Objective: To investigate the clinicopathological characteristics of SMARCA4-deficient thoracic undifferentiated tumors, and the diagnostic value of the cells in serous effusion. Methods: Eleven cases of SMARCA4-deficient tumor were collected from the Affiliated Hospital of Hebei University, China from January 2018 to July 2023, which were diagnosed using cell block of serous effusion. The clinical, histopathological, immunohistochemical and molecular genetic features were reviewed, along with related literature. Results: All the 11 patients were males with ages ranging from 54 to 77 years (median 64 years). Nine patients were smokers and two had an unknown smoking history. Most of them complained of cough and dyspnea with pleural effusion. The primary tumor sites included lung (9 cases), thoracic wall (1 case), and mediastinum (1 case), while 3 patients had a history of lung surgery. Histologically, tumor cells were large and pleomorphic, with increased nuclear-cytoplasmic ratio. They also showed round nuclei, conspicuous nucleoli, and basophilic cytoplasm in serous effusion. Immunohistochemically, tumor cells in all cases were negative for SMARCA4/BRG1, CKpan and CK7, but positive for SMARCB1/INI1. Some of the cases were positive for CD34 (7/11), synaptophysin (4/11) and SALL4 (2/11). Histologically, monotonous tumor cells formed solid sheets or anastomosing islands with poor cell adhesion and rhabdoid morphology. Brisk mitotic figures were accompanied by large areas of necrosis. Some cases focally exhibited syncytia, and some had bright cytoplasm and vesicular chromatin. The immunohistochemical profiles in the tumor tissues were consistent with those of cytology. Six cases were negative for PD-L1 (22c3). Among the 6 cases analyzed by targeted next generation sequencing, concurrent SMARCA4 and TP53 mutations were detected in all 6 cases. Some of the 6 tumors showed mutations of STK11, CDKN2A, and MET, and amplification of ERBB2, exon deletion of BRCA2, etc. Follow-up information was available in all cases and ranged from 2 to 24 months. The patients showed metastases to various sites, including lymph node, liver, kidney, adrenal gland, brain, bone and other sites. Four patients died of the tumor. The survival time of 4 patients who underwent radical resection or radiofrequency ablation was more than 13 months. Conclusions: SMARCA4-deficient thoracic sarcoma is a rare but highly aggressive tumor with dismal prognosis and rhabdomyoid features. It is difficult to diagnose this disease using only serous effusion samples. This tumor thus warrants careful consideration. Accurate diagnosis can greatly improve early diagnosis and treatment of these tumors.

[Clinical characteristics and prognosis analysis of 17 cases of SMARCA4-deficient chest tumors].

Objective: To analyze the clinical characteristics and prognosis of 17 patients with pathologically confirmed SMARCA4-deficient chest tumors. Methods: Seventeen patients with SMARCA4-deficient thoracic tumors diagnosed by pathology in the Affiliated Hospital of Jining Medical University from September 2021 to January 2023 were collected through Results Query System of Pathology Department, and the patients' general conditions, clinical symptoms, tumor markers, imaging features, treatment and regression were retrospectively analyzed, and literature review was performed. Results: A total of 17 patients were included in this study. Their clinical characteristics were characterized as follows: male/female=16/1, age 42-74 years, mean (64.0±5.7)years. Only 1 female had no clear smoking history, and 16 males had a smoking history, of whom 1 had 5 smoking pack-years, and the remaining 15 case had a smoking history of 20-100 smoking pack-years, with a mean of (68.5±44.5) smoking pack-years. Clinical symptoms were mainly cough and sputum, followed by chest tightness, hemoptysis and chest pain. Tumor markers CYFRA19-9 was elevated in 9 cases (3.79-16.61 ng/ml), CEA was elevated in 8 cases (5.37-295.93 ng/ml), and NSE was elevated in 6 cases (17.18-70.37 ng/ml). Imaging manifestations were intrapulmonary or mediastinal mass shadows, and the tumor involved the mediastinum in 9 cases, the upper lobe of the right lung in 6 cases, the upper lobe of the left lung in 5 cases, the lower lobe of the right lung in 3 cases, the lower lobe of the left lung in 3 cases; cervical or supraclavicular lymph node metastasis in 8 cases, pleural metastasis in 4 cases, hepatic metastasis in 3 cases, cerebral metastasis in 3 cases, bone metastasis in 2 cases, and subcutaneous metastasis in 1 case. Combining immuno-histochemistry and pathology, there were 6 cases of SMARCA4-deficient NSCLC and 11 cases of SMARCA4-deficient undifferentiated tumor. Eight patients were treated with platinum-contained chemotherapy agents, four of which were combined with immune checkpoint inhibitors, and one was treated with enzatinib; only one of the 9 patients achieved partial remission after treatment, and the remaining eight had progression of the tumors on chest CT after treatment. Five patients abandoned the treatment, and died in 6-month of follow-up. Three patients underwent surgery for resection, and there was no significant progression in the three patients in the 6 months of follow-up. Conclusions: Clinically, middle-aged and elderly men with a history of heavy smoking should be given high priority, especially in patients whose imaging mostly showed intrapulmonary, especially in upper lobes, and/or mediastinal masses, rapid lesion progression, and early distant metastasis, and who should be alerted to the possibility of SMARCA4-deficient thoracic tumors. Late clinical stage is a high risk factor for poor overall patient survival, and platinum-containing chemotherapy agents combined with immune checkpoint inhibitor therapy may be effective, and early surgery may improve patient prognosis.

SMARCB1/INI1-deficient undifferentiated tumour of the thorax: a case report and review of the literature.

The 5th WHO classification of thoracic tumours includes thoracic SMARCA4-deficient undifferentiated tumour (SMARCA4-UT) among the "other epithelial tumours of the lung" chapter. Herein, we present a case of undifferentiated thoracic neoplasm with retention of SMARCA4 expression, lack of NUT fusion protein and loss of SMARCB1/INI1 expression. After presenting the clinical and pathological features of the tumour, we carried out a review of the literature on the same topic. Albeit very rare, we believe this entity should be included in the heterogeneous group of undifferentiated neoplasms of the thorax.

[Thoracic SMARCA4-deficient undifferentiated tumor-pathological diagnosis and combined immune checkpoint inhibitor treatment].

We explored clinicopathological features and treatment strategies for thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). Thoracic SMARCA4-UT is a new entity recently acknowledged in the 2021 edition of World Health Organization Classification of Thoracic Tumors, and doctors are relatively unfamiliar with its diagnosis, treatment, and prognosis. Taking a case of SMARCA4-UT treated in Peking University First Hospital as an example, this multi-disciplinary discussion covered several hot issues on diagnosing and treating thoracic SMARCA4-UT, including histological features, immu- nohistochemical and molecular phenotype, immune checkpoint inhibitor (ICI) therapy, and pathological assessment of neoadjuvant therapy response. The patient was an older man with a long history of smoking and was admitted due to a rapidly progressing solid tumor in the lower lobe of the right lung. Histologically, tumor cells were epithelioid, undifferentiated, diffusely positive for CD34, and partially positive for SALL4.The expression of BRG1 protein encoded by SMARCA4 gene was lost in all of tumor cells, and next-generation sequencing(NGS)confirmed SMARCA4 gene mutation (c.2196T>G, p.Y732Ter). The pathological diagnosis reached as thoracic SMARCA4-UT, and the preoperative TNM stage was T1N2M0 (ⅢA). Tumor proportion score (TPS) detected by immunohistochemistry of programmed cell death 1-ligand 1 (PD-L1, clone SP263) was 2%. Tumor mutation burden (TMB) detected by NGS of 1 021 genes was 16. 3/Mb. Microsatellite detection showed the tumor was microsatellite stable (MSS). Neo-adjuvant therapy was implemented with the combined regimen of chemotherapy and ICI. Right lower lobectomy was performed through thoracoscopy after the two weeks' neoadjuvant. The pathologic assessment of lung tumor specimens after neoadjuvant therapy revealed a complete pathological response (CPR). The post-neoadjuvant tumor TNM stage was ypT0N0M0. Then, five cycles of adjuvant therapy were completed. Until October 2022, neither tumor recurrence nor metastasis was detected, and minimal residual disease (MRD) detection was negative. At present, it is believed that if BRG1 immunohistochemical staining is negative, regardless of whether SMARCA4 gene mutation is detected, it should be classified as SMARCA4-deficient tumors. SMARCA4-deficient tumors include a variety of carcinomas and sarcomas. The essential criteria for diagnosing SMARCA4-UT includes loss of BRG1 expression, speci-fic histological morphology, and exclude other common thoracic malignant tumors with SMARCA4-deficiency, such as squamous cell carcinoma, adenocarcinoma and large cell carcinoma. SMARCA4-UT is a very aggressive malignant tumor with a poor prognosis. It has almost no targeted therapy mutations, and little response to chemotherapy, but ICI is currently the only effective drug. The successful diagnosis and treatment for this case of SMARCA4-UT should enlighten significance for various kinds of SMARCA4-deficient tumors.

Cord Herniation through the Site of Undiagnosed Thoracic Dermoid Tumour during Spinal Anaesthesia; Report of a Case and Describing Ways to Avoid.

Spinal anaesthesia (SA) is one of the most prevalent types of anaesthetic procedures. There are very few reports of cord herniation through the site of spinal canal stenosis due to tumour. A 33-year-old female presented with acute paraparesis after spinal anaesthesia for caesarean section. Magnetic resonance imaging (MRI) revealed an intradural mass from posterior of T6 to T8-T9 interface. We operated the patient and after laminectomy of T6 to T9, dermoid tumour containing hairs was totally resected and cord was completely decompressed. After 6 months, the patient is without any neurological deficit. Puncturing the dura with cerebrospinal fluid (CSF) in the presence of an extramedullary mass could cause cord herniation through the blockade. In these cases, awareness about related signs even in absence of symptoms or complaints could help us to prevent post-SA neurological deficit.

Significance of dissection in each regional lymph-node station of esophageal cancer based on efficacy index and recurrence patterns after curative esophagectomy.

BACKGROUND: The optimal extent of lymph-node (LN) dissection in esophageal cancer has not been established. Although the frequency and patterns of recurrence in each regional LN station after radical dissection are important in determining the regional LNs of thoracic esophageal cancer to be routinely dissected, this information has not been investigated sufficiently. We studied the significance of dissection at each LN station based on their recurrence patterns. METHODS: Six hundred and twelve patients with esophageal cancer who underwent curative esophagectomy were studied. The incidence and pattern of recurrence (systemic or non-systemic) at each regional LN station were analyzed. To compare the significance of dissection among regional LNs, the efficacy index (EI) was also calculated. RESULTS: Regional LN recurrence was diagnosed in 101 (16.5%) patients. Among the regional LNs, recurrent laryngeal nerve, paraesophageal, and perigastric LNs showed higher EIs (3.1-6.7). Pretracheal and posterior thoracic para-aortic LNs showed low EIs (0-0.2). Supraclavicular LNs had moderate EIs (1.7-2.0). The recurrence rate was highest in the pretracheal LN, followed by the supraclavicular LNs. The majority (81.8%) of the pretracheal LN had a systemic recurrence, while about half (right: 60.0%, left: 43.8%) of the supraclavicular LNs had a systemic recurrence. CONCLUSION: Due to the high incidence of systemic recurrence or low EI for pretracheal and posterior thoracic para-aortic LNs, we suggest that these LN stations be regarded as non-regional LNs and be excluded from routine dissection. Supraclavicular LNs may also be excluded from routinely dissected stations.