Differentiating low-risk thymomas from high-risk thymomas: preoperative radiomics nomogram based on contrast enhanced CT to minimize unnecessary invasive thoracotomy.

BACKGROUND: This study was designed to develop a combined radiomics nomogram to preoperatively predict the risk categorization of thymomas based on contrast-enhanced computed tomography (CE-CT) images. MATERIALS: The clinical and CT data of 178 patients with thymoma (100 patients with low-risk thymomas and 78 patients with high-risk thymomas) collected in our hospital from March 2018 to July 2023 were retrospectively analyzed. The patients were randomly divided into a training set (n = 125) and a validation set (n = 53) in a 7:3 ratio. Qualitative radiological features were recorded, including (a) tumor diameter, (b) location, (c) shape, (d) capsule integrity, (e) calcification, (f) necrosis, (g) fatty infiltration, (h) lymphadenopathy, and (i) enhanced CT value. Radiomics features were extracted from each CE-CT volume of interest (VOI), and the least absolute shrinkage and selection operator (LASSO) algorithm was performed to select the optimal discriminative ones. A combined radiomics nomogram was further established based on the clinical factors and radiomics scores. The differentiating efficacy was determined using receiver operating characteristic (ROC) analysis. RESULTS: Only one clinical factor (incomplete capsule) and seven radiomics features were found to be independent predictors and were used to establish the radiomics nomogram. In differentiating low-risk thymomas (types A, AB, and B1) from high-risk ones (types B2 and B3), the nomogram demonstrated better diagnostic efficacy than any single model, with the respective area under the curve (AUC), accuracy, sensitivity, and specificity of 0.974, 0.921, 0.962 and 0.900 in the training cohort, 0.960, 0.892, 0923 and 0.897 in the validation cohort, respectively. The calibration curve showed good agreement between the prediction probability and actual clinical findings. CONCLUSIONS: The nomogram incorporating clinical factors and radiomics features provides additional value in differentiating the risk categorization of thymomas, which could potentially be useful in clinical practice for planning personalized treatment strategies.

Sequential development of diffuse panbronchiolitis and myasthenia gravis after thymectomy for thymic neoplasm: a case report.

BACKGROUND: Myasthenia gravis (MG) is the most common paraneoplastic disorder associated with thymic neoplasms. MG can develop after thymectomy, and this condition is referred to post-thymectomy myasthenia gravis (PTMG). Diffuse panbronchiolitis (DPB), is a rare form of bronchiolitis and is largely restricted to East Asia, has been reported in association with thymic neoplasms. Only three cases of combined MG and DPB have been reported in the literature. CASE PRESENTATION: A 45-year-old Taiwanese woman presented to our hospital with productive cough, rhinorrhea, anosmia, ear fullness, shortness of breath, and weight loss. She had a history of thymoma, and she underwent thymectomy with adjuvant radiotherapy 7 years ago. Chest computed tomography scan revealed diffuse bronchitis and bronchiolitis. DPB was confirmed after video-assisted thoracoscopic surgery lung biopsy, and repeated sputum cultures grew Pseudomonas aeruginosa. She has been on long-term oral azithromycin therapy thereafter. Intravenous antipseudomonal antibiotics, inhaled amikacin, as well as oral levofloxacin were administered. Three months after DPB diagnosis, she developed ptosis, muscle weakness, and hypercapnia requiring the use of noninvasive positive pressure ventilation. MG was diagnosed based on the acetylcholine receptor antibody and repetitive stimulation test results. Her muscle weakness gradually improved after pyridostigmine and corticosteroid therapies. Oral corticosteroids could be tapered off ten months after the diagnosis of MG. She is currently maintained on azithromycin, pyridostigmine, and inhaled amikacin therapies, with intravenous antibiotics administered occasionally during hospitalizations for respiratory infections. CONCLUSIONS: To our knowledge, this might be the first case report of sequential development of DPB followed by PTMG. The coexistence of these two disorders poses a therapeutic challenge for balancing infection control for DPB and immunosuppressant therapies for MG.

Preoperative management and postoperative complications in 9 dogs undergoing surgical treatment of thymic-associated myasthenia gravis.

Objective: Thymoma-associated paraneoplastic syndromes in dogs and cats include myasthenia gravis, hypercalcemia, exfoliative dermatitis, erythema multiforme, T-cell lymphocytosis, myocarditis, anemia, and polymyositis. Paraneoplastic myasthenia gravis (MG) is the most commonly reported paraneoplastic syndrome in dogs with thymic epithelial tumors. The objective of this study was to examine cases of canine thymic-associated MG treated surgically, with the specific objective of providing an updated clinical picture of the preoperative management, postoperative complications, and outcomes of these cases. Animals: Nine dogs with paraneoplastic MG underwent surgical removal of a thymic epithelial tumor. Procedure: Medical records of dogs with MG that received surgical treatment of a thymic epithelial tumor between January 1, 2012 and October 1, 2022 were obtained from 4 veterinary teaching hospitals. Descriptions of perioperative MG management, complications, and outcomes were reported. Results: Six of the 9 dogs received medical therapy for MG, with either a cholinesterase inhibitor (4 dogs) or a cholinesterase inhibitor and immunosuppressive agent (2 dogs), before surgery. The median duration of medical therapy for MG before surgery was 7.5 d (range: 2 to 60 d). Three of 9 dogs experienced immediate postoperative complications and were euthanized. Six of 9 dogs (66.6%) survived to discharge and 3 of 6 dogs that survived to discharge were alive at the time of writing. At the time of writing, 3 of 6 dogs had complete resolution of clinical signs attributable to MG and 2 of 6 had partial resolution. The median time from surgery to resolution of clinical signs of MG in these dogs was 63 d (range: 2 to 515 d). Conclusion: Dogs with thymic epithelial tumors and paraneoplastic MG are at a high risk for perioperative complications. Clinical relevance: The findings of this study corroborate previous literature stating that paraneoplastic MG is a poor prognostic indicator for dogs with thymic epithelial tumors, while also highlighting the variation in approaches to clinical management of thymic-associated MG in veterinary medicine and the lack of established protocols guiding perioperative management.

Prise en charge préopératoire et complications postopératoires chez 9 chiens subissant un traitement chirurgical de la myasthénie grave associée au thymus. Objectif: Les syndromes paranéoplasiques associés au thymome chez le chien et le chat comprennent la myasthénie grave, l'hypercalcémie, la dermatite exfoliative, l'érythème polymorphe, la lymphocytose à cellules T, la myocardite, l'anémie et la polymyosite. La myasthénie paranéoplasique (MG) est le syndrome paranéoplasique le plus fréquemment rapporté chez les chiens atteints de tumeurs épithéliales thymiques. L'objectif de cette étude était d'examiner les cas de MG canine associée au thymus traités chirurgicalement, dans le but spécifique de fournir un tableau clinique actualisé de la prise en charge préopératoire, des complications postopératoires et des résultats de ces cas. Animaux: Neuf chiens atteints de MG paranéoplasique ont subi l'ablation chirurgicale d'une tumeur épithéliale thymique. Procédure: Les dossiers médicaux des chiens atteints de MG ayant reçu un traitement chirurgical d'une tumeur épithéliale thymique entre le 1er janvier 2012 et le 1er octobre 2022 ont été obtenues auprès de 4 hôpitaux universitaires vétérinaires. Des descriptions de la prise en charge péri-opératoire de la MG, des complications et des résultats ont été rapportées. Résultats: Six des 9 chiens ont reçu un traitement médical pour la MG, avec soit un inhibiteur de la cholinestérase (4 chiens), soit un inhibiteur de la cholinestérase et un agent immunosuppresseur (2 chiens), avant la chirurgie. La durée médiane du traitement médical de la MG avant la chirurgie était de 7,5 jours (plage : 2 à 60 jours). Trois des neuf chiens ont présenté des complications postopératoires immédiates et ont été euthanasiés. Six des 9 chiens (66,6 %) ont survécu jusqu'à leur sortie et 3 des 6 chiens qui ont survécu jusqu'à leur sortie étaient en vie au moment de la rédaction. Au moment de la rédaction de cet article, 3 chiens sur 6 présentaient une résolution complète des signes cliniques attribuables à la MG et 2 chiens sur 6 présentaient une résolution partielle. Le délai médian entre l'intervention chirurgicale et la résolution des signes cliniques de MG chez ces chiens était de 63 jours (plage : 2 à 515 jours). Conclusion: Les chiens atteints de tumeurs épithéliales thymiques et de MG paranéoplasique présentent un risque élevé de complications périopératoires. Pertinence clinique: Les résultats de cette étude corroborent la littérature antérieure indiquant que la MG paranéoplasique est un indicateur de mauvais pronostic pour les chiens atteints de tumeurs épithéliales thymiques, tout en soulignant également la variation des approches de prise en charge clinique de la MG associée au thymus en médecine vétérinaire et le manque de protocoles établis de gestion guidant les interventions périopératoires.(Traduit par Dr Serge Messier).

Challenge of concomitant thymoma resection and myocardial revascularization: A Case Report.

Myocardial revascularization in patients presenting with an anterior mediastinal mass poses considerable challenges. In this report, we outline two cases involving patients with anterior mediastinal masses who underwent surgical resection alongside concurrent myocardial revascularization. One patient underwent coronary artery bypass graft surgery, while the other was treated by percutaneous coronary intervention with drug-eluting stent placement. Both patients fully recovered from the relative procedures and were discharged within two weeks post-surgery, ultimately diagnosed with thymoma. The concomitant intervention offered the advantage of promptly addressing both conditions, and it was performed safely through a collaborative multidisciplinary effort.

Efficacy of robot-assisted thoracoscopic surgery for managing thymoma recurrence following sternotomy: a case report.

This report addresses the management strategy and effectiveness of robot-assisted thoracoscopic surgery (RATS) for treating local recurrence of thymoma, a condition often complicated by severe adhesions and limited data on re-operation following median sternotomy. We report about a 43-year-old man with thymoma recurrence 4 years after thymothymectomy via a median sternotomy. Follow-up computed tomography revealed a nodule adjacent to the left brachiocephalic vein, indicating possible thymoma recurrence. Thus, re-operation was performed using a left-sided approach via RATS with an artificial pneumothorax. The manipulation space was secured with an artificial pneumothorax, and multidirectional manipulation using RATS demonstrated good efficacy. Collectively, this case highlights the efficacy of RATS as a viable approach for managing thymoma recurrence in mediastinal locations, particularly when sternotomy is complicated by severe adhesions.

Intrathyroidal thymic carcinoma.

A young woman in her early 30s presented with a right thyroid mass and progressive hoarseness due to a right vocal cord palsy. The preoperative fine-needle aspiration cytology was classified as Bethesda V and she underwent a total thyroidectomy and neck dissection. Intraoperatively, the thyroid mass was adherent to the oesophagus, trachea and encasing the right recurrent laryngeal nerve which was sacrificed. Final histopathology diagnosed a rare subtype of thyroid cancer known as intrathyroidal thymic carcinoma (ITC). She was then sent for adjuvant radiotherapy after a multidisciplinary tumour board discussion. This case report highlights the difficulty in preoperative diagnosis of ITC and the importance of immunohistochemical staining in clinching the diagnosis. In view of its rarity, there have been no published consensus on the treatment of ITC, hence we would like to share some learning points through a comprehensive literature review.

Ectopic cervical thymoma: a rare entity in the anterior neck.

Thymoma is a rare malignancy with usual location in the antero-superior mediastinum. Ectopic cervical thymoma (ECT) is an extremely rare tumor that originates from ectopic tissue, and is caused by the aberrant migration of the embryonic thymus. Our patient was a 56-year-old man who had a nodular lesion in the neck for several years. Computed tomography and Enhanced magnetic resonance imaging were performed. He underwent surgery, and a histological examination resulted in a diagnosis of type AB thymoma.

[Thymoma with Partial Anomalous Pulmonary Venous Drainage from the Left Upper Lobe:Report of a Case].

A 73-year-old woman presented with left anterior chest pain and back pain. Computed tomography (CT) scan showed an anterior mediastinal tumor. It also showed partial anomalous pulmonary venous drainage (left superior pulmonary vein draining into the left brachiocephalic vein), and the tumor was located near the left brachiocephalic vein. The operation was performed through a median sternotomy to resect the thymus and tumor with partial resection of the left upper lobe due to the tumor's adhesion to the left upper lobe. One of the vascular anomalies encountered in adult thoracic surgery is partial anomalous pulmonary venous drainage. It is important to recognize the presence of such an anomaly on imaging and to anticipate the surgical procedure with a preoperative surgical technique.

Does Surgical Removal of the Thymus Have Deleterious Consequences?

The role of immunosenescence, particularly the natural process of thymic involution during aging, is increasingly acknowledged as a factor contributing to the development of autoimmune diseases and cancer. Recently, a concern has been raised about deleterious consequences of the surgical removal of thymic tissue, including for patients who undergo thymectomy for myasthenia gravis (MG) or resection of a thymoma. This review adopts a multidisciplinary approach to scrutinize the evidence concerning the long-term risks of cancer and autoimmunity postthymectomy. We conclude that for patients with acetylcholine receptor antibody-positive MG and those diagnosed with thymoma, the removal of the thymus offers prominent benefits that well outweigh the potential risks. However, incidental removal of thymic tissue during other thoracic surgeries should be minimized whenever feasible.

Our experience with robotic-assisted thymic surgery.

Thoracic surgery is increasingly influenced by the development of minimally invasive approaches which have also influenced surgery in the area of the anterior mediastinum. The previously standard approach to the thymus via partial sternotomy was gradually replaced by the videothoracoscopic approach in most cases. In recent years, robotically assisted surgery has been gaining ground worldwide in this area, as well. The aim of our paper is to provide a comprehensive overview of procedures in the field of the thymus, including their indications, and to share our first experience with robot-assisted thymus surgery. At the 3rd Department of Surgery, since the start of the robot-assisted thymus surgery program, 23 thymectomies have been performed using this approach, of which 17 were performed for thymoma, 3 for myasthenia gravis, and 3 for parathyroid adenoma localized in thymus tissue. From our experience and the available data, it follows that the length of hospitalization, the rate of complications and the resulting effect of robot-assisted procedures is comparable to VTS procedures; however, the robot-assisted surgery also allows for mini-invasive treatment even in significantly obese patients and in patients with advanced thymic tumors who would otherwise be indicated for open thymectomy.

Postoperative radiotherapy does not improve survival in patients with Masaoka-Koga stage IIB thymomas: A propensity score matching study based on the SEER database.

This study, based on a population, explored the prognostic value of postoperative radiotherapy (PORT) for Masaoka-Koga IIB stage thymomas. Patients diagnosed with thymoma from 2004 to 2017 in the Surveillance, Epidemiology, and End Results (SEER) database were included in the retrospective study. Through propensity score matching, the baseline characteristics of the patients were successfully matched to mitigate the selection bias of PORT. Survival rates and survival curves were compared between the PORT and non-PORT groups, with potential confounding factors addressed using a multivariate Cox regression model. In this study, 785 cases of IIB stage thymoma were included from the SEER database, and 303 patients were successfully matched between PORT and non-PORT groups through propensity score matching, with no significant differences in baseline characteristics. In the PORT and non-PORT groups, 10-year overall survival rates were 65.2% versus 59.6%, and cancer-specific survival rates were 87.0% vs. 84.4%, PORT did not yield statistically significant improvements in overall survival (P = .275) or cancer-specific survival (P = .336) for stage IIB thymomas. Based on the SEER database, the results of our study indicated that PORT does not confer a significant survival benefit for IIB stage thymomas.

Survival Outcome After Surgery in Patients With Thymoma Distant Recurrence.

OBJECTIVE: The aim of this study is to describe characteristics and survival outcome of patients who underwent surgical treatment for distant thymoma relapse according to the definition of the International Thymic Malignancy Interest Group. METHODS: Data of patients affected by thymoma recurrence from four different institutions were collected and retrospectively reviewed. Patients with locoregional metastases who underwent nonsurgical therapies and with incomplete data on follow-up were excluded. According to the International Thymic Malignancy Interest Group distant recurrence definition, patients with recurrence due to hematogenic localization were included. Clinical and pathologic characteristics were described using descriptive statistics, whereas survival outcome was calculated using Kaplan-Meier curves and Cox regression analysis. RESULTS: The analysis was conducted on 40 patients. A single localization was present in 13 patients, the relapse was intrathoracic in 28 cases (70%), and lung involvement was found in 26 cases. The liver was operated in seven cases, whereas other kinds of abdominal involvement were detected in eight cases. Adjuvant treatment was administered in 22 cases (55%).Five- and 10-year overall survival (OS) were 67% and 30%, respectively. Univariable analysis identified as significant favorable factor a low-grade histology (A, B1, B2): five-year OS at 92.3% versus 53.3% in high-grade (B3-C) (p = 0.035). Site of recurrence and number of localization did not influence the prognosis, but in patients with adjuvant therapy administration, there was a survival advantage also if not statistically significant: five-year OS 84.8% versus 54.5% in patients without adjuvant therapy (p = 0.101).Multivariable analysis confirmed as independent prognostic factor low-grade histology: hazard ratio = 0.176, 95% confidence interval 0.042-0.744, p = 0.018. CONCLUSIONS: Our study revealed a good survival outcome in patients who underwent surgery for distant thymoma recurrence, independently from the number and site of the relapse localization. Patients with A, B1, or B2 histology presented a significantly better survival than patients with B3-C.

Recommendations for Post-Operative RadioTherapy After Complete Resection of Thymoma-a French DELPHI Consensus Initiative.

INTRODUCTION: Thymomas are rare intrathoracic malignancies that can relapse after surgery. Whether or not Post-Operative RadioTherapy (PORT) should be delivered after surgery remains a major issue. RADIORYTHMIC is an ongoing, multicenter, randomized phase 3 trial addressing this question in patients with completely R0 resected Masaoka-Koga stage IIb/III thymoma. Experts in the field met to develop recommendations for PORT. METHODS: A scientific committee from the RYTHMIC network identified key issues regarding the modalities of PORT in completely resected thymoma. A DELPHI method was used to question 24 national experts, with 115 questions regarding the following: (1) imaging techniques, (2) clinical target volume (CTV) and margins, (3) dose constraints to organs at risk, (4) dose and fractionation, and (5) follow-up and records. Consensus was defined when opinions reached more than or equal to 80% agreement. RESULTS: We established the following recommendations: preoperative contrast-enhanced computed tomography (CT) scan is recommended (94% agreement); optimization of radiation delivery includes either a four-dimensional CT-based planning (82% agreement), a breath-holding inspiration breath-hold-based planning, or daily control CT imaging (81% agreement); imaging fusion based on cardiovascular structures of preoperative and planning CT scan is recommended (82% agreement); right coronary and left anterior descending coronary arteries should be delineated as cardiac substructures (88% agreement); rotational RCMI/volumetric modulated arc therapy is recommended (88% agreement); total dose is 50 Gy (81% agreement) with 1.8 to 2 Gy per fraction (94% agreement); cardiac evaluation and follow-up for patients with history of cardiovascular disease are recommended (88% agreement) with electrocardiogram and evaluation of left ventricular ejection fraction at 5 years and 10 years. CONCLUSION: This is the first consensus for PORT in thymoma. Implementation will help to harmonize practices.

Is Minimally Invasive Resection of Large Thymoma Appropriate?

BACKGROUND: Current practice patterns suggest open rather than minimally invasive (MIS) approaches for thymomas >4 cm. We hypothesized there would be similar perioperative outcomes and overall survival between open and MIS approaches for large (>4 cm) thymoma resection. METHODS: The National Cancer Database was queried for patients who underwent thymectomy from 2010 to 2020. Surgical approach was characterized as either open or MIS. The primary outcome was overall survival and secondary outcomes were margin status, and length of stay (LOS). Differences between approach cohorts were compared after a 1:1 propensity match. RESULTS: Among 4121 thymectomies, 2474 (60%) were open and 1647 (40%) were MIS. Patients undergoing MIS were older, had fewer comorbidities, and had smaller tumors (median; 4.6 vs 6 cm, P < .001). In the unmatched cohort, MIS and open had similar 90-day mortality (1.1% vs 1.8%, P = .158) and rate of positive margin (25.1% vs 27.9%, P = .109). MIS thymectomy was associated with shorter LOS (2 (1-4) vs 4 (3-6) days, P < .001). Propensity matching reduced the bias between the groups. In this cohort, overall survival was similar between the groups by log-rank test (P = .462) and multivariate cox hazard analysis (HR .882, P = .472). Multivariable regression showed shorter LOS with MIS approach (Coef -1.139, P < .001), and similar odds of positive margin (OR 1.130, P = .150). DISCUSSION: MIS has equivalent oncologic benefit to open resection for large thymomas, but is associated with shorter LOS. When clinically appropriate, MIS thymectomy may be considered a safe alternative to open resection for large thymomas.

Long-term follow-up of non-myasthenic patients with early-stage thymoma who underwent extended thymectomy or limited resection.

BACKGROUD: The standard resection for early-stage thymoma is total thymectomy and complete tumour excision with or without myasthenia gravis but the optimal surgery mode for patients with early-stage non-myasthenic thymoma is debatable. This study analysed the oncological outcomes for non-myasthenic patients with early-stage thymoma treated by thymectomy or limited resection in the long term. METHODS: Patients who had resections of thymic neoplasms at Taipei Veteran General Hospital, Taiwan between December 1997 and March 2013 were recruited, exclusive of those combined clinical evidence of myasthenia gravis were reviewed. A total of 113 patients were retrospectively reviewed with pathologic early stage (Masaoka stage I and II) thymoma who underwent limited resection or extended thymectomy to compare their long-term oncologic and surgical outcomes. RESULTS: The median observation time was 134.1 months [interquartile range (IQR) 90.7-176.1 months]. In our cohort, 52 patients underwent extended thymectomy and 61 patients underwent limited resection. Shorter duration of surgery (p < 0.001) and length of stay (p = 0.006) were demonstrated in limited resection group. Six patients experienced thymoma recurrence, two of which had combined myasthenia gravis development after recurrence. There was no significant difference (p = 0.851) in freedom-from-recurrence, with similar 10-year freedom-from-recurrence rates between the limited resection group (96.2 %) and the thymectomy group (93.2 %). Tumour-related survival was also not significantly different between groups (p = 0.726).result CONCLUSION: Patients with early-stage non-myasthenic thymoma who underwent limited resection without complete excision of the thymus achieved similar oncologic outcomes during the long-term follow-up and better peri-operative results compared to those who underwent thymectomy.