Resection Of Thymoma Research Articles

Surgical Resection of Thymoma Still Represents the First Choice of Treatment

The aim of this study was to analyze the clinicopathological factors, treatment strategies and survival rates after surgical resection of thymoma. Between 12/1997 and 5/2010, 42 patients underwent surgical resection of the thymus. The presence of a thymoma was determined by histological examination in 23 patients, while patients with hyperplasia of the thymus (n = 19) were excluded from further analysis. Myasthenia gravis coexisted in 9/23 (39.1%) patients. Thymomas were classified according to the Masaoka staging system (I: n = 6 [26.1%], IIa: n = 7 [30.4%], IIb: n = 2 [8.7%], III: n = 1 [4.4%], IVa: n = 7 [30.4%]) and the WHO histological classification (A: n = 4 [17.4%], AB: n = 5 [21.7%], B1: n = 1 [4.4%], B2: n = 8 [34.8%], B3: n = 3 [13%], C: n = 2 [8.7%]). Recurrence of thymoma was documented in three (13%) patients. After a mean follow-up of 58.4 months, 21 (91.3%) patients are alive. The overall survival rate was 95% and 87.8%, at 2 and 5 years, respectively. The disease-free interval at 5 years was 85% for the 17 (73.9%) patients with complete resection. Surgical resection of thymoma is the preferred treatment, because it is safe and effective with a low rate of recurrence and a good long-term survival. Advanced and invasive thymomas require a multimodal approach for better local tumor control and further improvement of prognosis.

Evaluation of the Role of Radiation Therapy in the Management of Malignant Thymoma

The management of patients diagnosed with thymoma remains unclear. This report attempts to identify the impact of adjuvant radiotherapy on overall survival (OS) and cause-specific survival (CSS) in patients diagnosed with thymoma. Patients diagnosed with thymic malignancy between 1973 and 2003 were retrospectively identified from centers participating in the Surveillance, Epidemiology, and End Results (SEER) program. Those patients classified as having thymic carcinoma were excluded from this analysis. OS and CSS were estimated by the Kaplan-Meier method. Outcomes for patients treated with and without radiation therapy were compared using the log-rank test. Multivariate analysis was performed with the Cox proportional hazards model to analyze factors predictive of OS and CSS. A total of 1,464 patients were identified as having thymic malignancy, and of these, 1,254 patients were identified as having malignant thymoma. The median follow-up time was 41 months (range, 4-337 months). Among patients who did not receive radiotherapy (RT), the 10-year rate of OS was 41% compared to 42% for those who did receive RT (p = 0.06). The median OS for the patients who did not receive RT was 80 months compared to 97 months for those who did receive RT. In patients with Masaoka stage II-III malignancy, OS was significantly improved with RT (p = 0.002), and a trend in improved CSS was observed (p = 0.1). Patients were also analyzed based on resection status. For those patients who had an incomplete excision, the 10-year OS was 63% with RT and 46% without RT (p = 0.38). On multivariate analysis, factors predictive of OS included age, extent of surgery, stage, and number of lymph nodes examined. This study reports treatment results of a large cohort of patients who were diagnosed with malignant thymoma. This study demonstrates that the use of RT following resection for thymoma significantly improves OS for those with regional disease and marginally improves CSS.

Steroid receptor expression in thymomas and thymic carcinomas

Although protein expressions of glucocorticoid receptor (GR), estrogen receptors (ERα and ERβ), progesterone receptor A (PgR-A), and androgen receptor (AR) were shown to play roles in the growth and differentiation of normal thymus and thymic tumors, to the authors' knowledge their association with patient characteristics and prognosis has yet to be determined. A series of 140 thymic epithelial tumors (57 type A + AB thymomas, 40 type B1 + B2 thymomas, 6 type B3 thymomas, and 37 thymic carcinomas) were examined for GR, ERα, ERβ, PgR-A, and AR expression using immunohistochemistry. In addition, the correlation between expression of these hormone receptors and clinicopathologic factors and overall survival (OS) was assessed. GR and ERβ demonstrated a high rate of expression in thymomas and thymic carcinomas (82.9% and 76.4%, respectively), whereas rates of ERα, PgR-A, and AR expression were low (13.6%, 0.71%, and 23.6%, respectively). A significant correlation (P < .05) was found between ERα expression and tumor size and between ERβ expression and tumor stage. Multivariate analyses revealed that histologic subtype (P = .0039), tumor stage (P = .0012), and GR expression (P = .0025) were significantly correlated with the 10-year OS rate. GR and ERβ demonstrated high rates of expression in thymomas and thymic carcinomas. Furthermore, multivariate analysis revealed that GR expression was associated with better prognosis in patients with surgically resected thymomas and thymic carcinomas.

Comparison of surgical techniques for early-stage thymoma: Feasibility of minimally invasive thymectomy and comparison with open resection

The minimally invasive, video-assisted thoracoscopic surgical (VATS) approach to resection of the thymus is frequently practiced for benign disease; however, a VATS approach for thymoma remains controversial. The objective of the present study was to evaluate the feasibility of VATS thymectomy for the treatment of early-stage thymoma and to compare the outcomes with those after open resection. A retrospective review of 40 patients who underwent surgical resection of early-stage thymoma during a 12-year period was conducted. Data on patient characteristics, morbidity, recurrence, and survival were collected. The primary endpoint studied was overall survival. Of the 40 patients, 14 underwent thymectomy for stage I and 26 for stage II thymoma; 19 were men and 21 were women (median age, 64 years; range, 35-86 years). Open thymectomy was performed in 22 patients, and VATS was performed in 18. The operative mortality rate was 0%. The tumor stage and number of patients undergoing adjuvant radiotherapy were comparable in both surgical groups. The median length of hospital stay was shorter in the VATS group (3 days) than in the open group (5 days) (P = .0001). The median follow-up was 36 months. No significant differences were found in the estimated recurrence-free and overall 5-year survival rates (83%-100%) between the 2 groups. VATS of early-stage thymoma appears safe and feasible and was associated with a shorter hospital stay. The oncologic outcomes were comparable in the open and VATS groups during intermediate-term follow-up. Additional follow-up is required to evaluate the long-term results of thoracoscopic thymectomy for early-stage thymoma.

A Case of Pleural Metastasis 6 Years after Complete Surgical Resection of Invasive Thymoma

Herein, we report a case of recurrent pleural metastasis after complete resection of invasive thymoma that was successfully treated with surgical resection. Thymoma and thymic carcinoma are uncommon neoplasms derived from the epithelial cells of the thymus. Approximately 30% to 5 0% of thymomas are asymptomatic at the time of diagnosis. However, these cancers may present with constitutional or local pressure symptoms and sometimes with paraneoplastic syndromes, especially myasthenia gravis. Surgical resection is the mainstay of thymoma treatment and has been shown to remarkably improve long-term survival. Despite complete resection, local recurrences are frequent, and surgery is the cornerstone of therapy even in cases of recurrent thymoma. We experienced a 67-year-old male patient with pleural metastasis that developed 6 years after complete surgical resection of invasive thymoma. The pleural mass was excised by video-assisted thoracoscopic surgery. Histopathological examination revealed an invasive World Health Organization (WHO) type B2 thymoma.

Successful treatment with immunosuppressive therapy for aplastic anemia developed after resection of thymoma

Successful treatment with immunosuppressive therapy for aplastic anemia developed after resection of thymoma

Thymoma followed by aplastic anemia

Aplastic anemia is an uncommon complication of thymoma and is extremely infrequent after the surgical removal of a thymic tumor. Aplastic anemia is a result of marrow failure and is characterized by peripheral pancytopenia and severely depressed marrow cellularity; it may be an autoimmune manifestation of thymoma. As thymoma-associated hematological dyscrasias, which include pure red cell aplasia, aplastic anemia and myasthenia gravis, are supposed to be of immunologic origin, two cases of very severe aplastic anemia following the resection of lymphocytic thymomas treated with immunosuppression are herein presented.

Thymoma: inter-relationships among World Health Organization histology, Masaoka staging and myasthenia gravis and their independent prognostic significance: a single-centre experience

In thymomas, World Health Organization (WHO) histology, Masaoka stage and myasthenia gravis (MG) have long been considered important for patient management and outcome. Their role has been independently investigated in the past. Few studies, however, focussed on the correlations among these variables. The aim of the present study was to retrospectively evaluate, in our patient population of resected thymomas, the inter-relationships among MG, WHO histology and Masaoka stage, and to look at how and to what extent one variable is associated with the other two in terms of clinical presentation and survival. From January 1990 to October 2008, 255 patients received resection of thymoma. MG was present in 105 cases (41%). Histology by WHO was: 25 A (10%), 72 AB (28%), 65 B1 (25%), 69 B2 (27%) and 24 B (9%). Masaoka staging was stage I, 54 cases (21%), stage II, 86(34%), stage III 79 (31%), and stage IVA 36 (14%). Ordinal and logistic regression models were undertaken to analyse correlations among ordinal (WHO histology and Masaoka stage) and categorical (MG, A vs B WHO types) variables. Univariate and multivariate survival analysis were also performed using the same covariates. Overall survival (OS) and disease-free survival (DFS) were calculated. MG was associated with early Masaoka stages (odds ratio (OR) 0.45, 95% confidence interval (CI) 0.33-0.62) and B-type thymomas (OR 1.59, 95% CI 1.23-2.05). B-type thymomas were associated with high Masaoka stage (OR 0.46, 95% CI 0.36-0.60). High Masaoka stage was associated with non-MG (OR 3.27; 95% CI 2.00-5.34). In univariate survival analysis, MG (p = 0.01) and Masaoka stage (p = 0.0001) were significant prognostic indicators using OS. Using DFS, WHO histology (A/AB vs B1/B2/B3 types) (p = 0.05) and Masaoka stage (p = 0.0001) had a prognostic significance. In multivariate analysis, only Masaoka stage was an independent prognostic covariate using OS (hazard ratio (HR) 2.57, 95% CI 1.46-4.52, p = 0.001) and DFS (HR 3.18, 95% CI 1.56-6.52, p = 0.001). In thymomas, MG, WHO histology and Masaoka stage are inter-related. MG has an influence on histology and stage at presentation, while two clinical/histologic patterns are more likely: early Masaoka stage A/AB WHO type and high Masaoka stage/B WHO type. Among the three factors, only Masaoka stage had a prognostic significance on OS and DFS. Our results suggest that a consistent staging system for thymomas should take into account all three variables.

Does a relationship exist between the number of thoracoscopic thymectomies performed and the learning curve for thoracoscopic resection of thymoma in patients with myasthenia gravis?

This study aimed to analyze surgeons' learning curve for thymoma resection with video-assisted thoracoscopic surgery (VATS). Two hundred and eleven myasthenia gravis patients had VATS thymic resections, including 25 patients with a thymoma. Three groups of surgeries, according to the order of operations, were analyzed: Group A comprised the first 70 thymectomies, Group B comprised the second 70 thymectomies, and Group C comprised the final 71 thymectomies. We compared the groups on a set of preoperative (age, gender, body mass index, and Osserman stage), operative (number in each group, size, and Masaoka stage), and postoperative (complications and length of stay) variables. A significant difference was observed in the number of thymoma operations (Group A: four patients, Group B: seven patients, and Group C: 14 patients; P: 0.031) and the duration of operation (Group A: 66min, Group B: 52min, and Group C: 48min; P: 0.024). A strong correlation was found between the duration of operation and order of patients (Pearson r: -0.554, P: 0.000). We recommend the start of a program for the resection of thymoma with VATS after surgical staff have performed 70 VATS thymectomy operations.

PONM08 Late recurrent thymoma: a case series

BackgroundIn patients with MG, thymoma may recur many years after initial resection.AimTo describe cases of late recurrent thymoma amongst myasthenic patients in a tertiary referral centre.MethodsCases of late recurrent thymoma...

Infective endocarditis caused by Moraxella nonliquefaciens in a percutaneous aortic valve replacement

First case of infective endocarditis on a percutaneous aortic valve replacement due to Moraxalla nonliquefaciens in 64 year old woman. It was successfully treated medically with antibiotics. She had not suitable for surgical aortic valve replacement due to 3 sternotomies for thymoma resection and subsequent radiotherapy with blocked major thoracic veins. Due to her azathioprine immunosuppresion (myasthenia) she may have been at increased endocarditis risk. We suggest prophylactic antibiotics at implant for this group in future.

Robotic-Assisted Resection of a Thymoma After Two Previous Sternotomies

Robotic-assisted surgery has emerged as a new strategy for resection of thymomas. It may provide an option for patients who have had prior thoracic procedures, reducing the risks involved with another open procedure. We present a patient with a thymoma occurring after two prior sternotomies for cardiac procedures. A robotic-assisted thymectomy was performed successfully, with no complications. The minimally invasive approach of robotic-assisted resection of thymomas provides a safe alternative to redo sternotomy.

Insulin‐like growth factor‐1 receptor and phosphorylated AKT‐serine 473 expression in 132 resected thymomas and thymic carcinomas

Thymic malignancies are rare tumors. The insulin-like growth factor-1 (IGF-1)/IGF-1 receptor (IGF-1R) system is involved in the development of the thymus. IGF-1R expression in thymic epithelial malignancies is unknown. The authors investigated the expression of IGF-1R and phosphorylated AKT serine 473 (p-AKT) by using immunohistochemistry and examined the clinicopathologic correlations in a retrospective, single-institution surgical series of 132 patients with thymic epithelial malignancies. Earlier disease stage, less aggressive histologic types, and complete resection were significant positive prognostic factors for disease-related survival and progression-free survival, and being a woman was a better prognostic factor for disease-related survival. IGF-1R and p-AKT protein levels were expressed in 20% and 36% of thymic tumors, respectively. Both markers were expressed more commonly in recurrent disease than in primary tumors, in more aggressive subtypes, and in more advanced disease stages. There was a trend toward better survival and progression-free survival in patients who were negative for IGF-1R or p-AKT expression in the whole series. When only the 91 primary tumors, IGF1R expression was associated with worse progression-free survival (P < .001). The current retrospective analysis demonstrated that disease stage, tumor histology, sex, and resection type were major prognostic factors in the survival of patients with thymic malignancies. The expression levels of IGF-1R and p-AKT in thymic tumors suggested that IGF-1R is a potential target for treatment.

Surgical outcomes and reevaluation of treatment strategies for thymomas

Improved histological typing systems for thymic tumors and advances in induction and adjuvant therapy have created the need to reevaluate strategies for the management of thymoma. We retrospectively studied 73 patients with completely resected thymomas unassociated with myasthenia gravis. The World Health Organization (WHO) histologic classification, clinicopathological features and surgical outcomes were analyzed. Overall survival was 66.2% at 10 years, and the median survival time was 169 months. According to the Masaoka staging system, overall survival rates at 10 years were 94.7% in stage I, 76.1% in stage II, 30% in stage III and 0% in stage IV. In the WHO classification, overall survival rates at 10 years were 91.9% in types A and AB, 50.9% in type B2 and not achieved in type B3. The disease-free interval was slightly shorter in patients with B2 and B3 disease than in those with type A, AB and B1 disease. Advanced thymomas were significantly associated with type B2 and B3 (p<0.01). In stage III and IV disease, adjuvant or neoadjuvant therapy was associated with better survival as compared to no adjuvant therapy (p=0.07). On multivariate analysis, Masaoka stage III and IV disease and extended thymectomy indicated significant, negative and independent risk factors for survival (p<0.01). Masaoka stage I and II thymomas or WHO type A and AB thymomas have favorable prognoses and do not require postoperative adjuvant therapy. Patients with stage III and IV thymomas require additional therapy after surgery.

A Non-invasive Thymoma that Occurred 29 Years After Complete Resection of a Non-invasive Thymoma Accompanied by a Microthymoma

A 55-year-old woman with a 7 cm non-invasive thymoma and myasthenia gravis had been treated by extended thymectomy via median sternotomy 29 years ago. A microscopic 0.15 cm thymoma (microthymoma) was incidentally found in the thymus during surgery. Twenty-nine years later, a 5 cm thymoma developed in the anterior mediastinum and was surgically treated. The non-invasive first thymoma, the microthymoma and the non-invasive third thymoma were all classified as type AB thymomas according to the World Health Organization (WHO) classification and showed extremely similar histological findings. We think the mechanism underlying the local recurrence of non-invasive thymomas would be intrathymic metastasis because of their clinical and pathological features.

Resection of an Invasive Thymoma Extending into the Superior Vena Cava and Right Atrium

Although invasive thymoma commonly infiltrates mediastinal structures, intracardiac extension from intracaval growth is rare. We present a case of invasive thymoma with intravascular invasion of the superior vena cava extending into the right atrium.

Prognostic Indicators After Surgery for Thymoma

We undertook a 20-year retrospective institutional study to investigate prognostic indicators after surgery for thymoma. From 1989 to 2009, 83 patients underwent surgical resection of thymoma or thymic carcinoma at our institution. Twelve of these patients were determined to have either World Health Organization type C disease or Masaoka stage IV-B disease and were excluded from analysis. The remaining 71 patients were reviewed. The majority of patients in this series were female 64.7% (n=46) with an overall average age of 51.0 years. The distribution of Masaoka stages I, II, III, and IV-A was 40.8% (n=29), 19.7% (n=14), 18.3% (n=13), and 21.1% (n=15), respectively. Thirteen of the 28 (46.2%) patients who presented with stage III or IV-A disease received preoperative chemotherapy. After a mean follow-up of 66 months (range, 6 to 241 months), 54 (75.3%) patients are alive and well while six are alive with disease. Eleven (16.0%) patients have died, but only 3 (4.3%) of these patients died of thymoma. The overall disease-specific survival was 97% and 89% at 5 and 10 years. Of the variables analyzed, only age was predictive of overall survival (p=0.03). Masaoka stages I to III as compared with stage IV-A was significantly predictive of disease-free survival (p<0.01). Long-term disease-specific survival can be expected not only after surgery for early stage thymoma but also after surgery for advanced disease, including patients with pleural metastases. However, patients who undergo surgery for stage IV-A disease have reduced disease-free survival. Late mortality due to secondary cancers and associated immunologic disorders was more frequent than mortality from thymoma in this series.

P48 Late recurrent thymoma: a case series

Background In patients with MG, thymoma may recur many years after initial resection. Aim To describe cases of late recurrent thymoma amongst myasthenic patients in a tertiary referral centre. Methods Cases of late recurrent thymoma were retrospectively identified and medical notes were reviewed. Results Five patients with a recurrent thymoma were identified. Four were male. The average age at first tumour presentation was 47.6. Four patients presented with MG. Four had apparent full excision of their thymoma. One patient had invasive disease at first presentation with incomplete resection and adjuvant radiotherapy. The mean disease free interval to recurrence was 13.5 years. Three cases of recurrence were detected on routine scanning whereas the other two patients presented with cough or chest pain. Four patients had repeat surgery. Two patients had palliative radiotherapy and two had chemotherapy. Three patients died. One patient was successfully treated for recurrence but developed sporadic motor neurone disease. One patient remains disease free 3 years after repeat surgery. Conclusion Thymoma may recur many years after surgery even if the initial tumour has apparently been completely resected. Tumour recurrence may be associated with a poor prognosis. Surveillance scanning after thymoma resection is essential and should continue indefinitely.

Cytomegalovirus Retinitis Associated with Good's Syndrome

To report a case of cytomegalovirus (CMV) retinitis associated with Good's syndrome. A 57-year-old man presented to our ophthalmology clinic with complaints of visual loss in the left eye for 2 weeks. His medical anamnesis revealed myasthenia gravis, thymoma resection, multiple chest infections, and Campylobacter septicemia. Left eye examination revealed mild anterior uveitis, moderate vitritis, and superotemporal active retinitis. Polymerase chain reaction of both aqueous humor and vitreous tap were positive for CMV DNA, which suggested CMV retinitis. The patient was treated with systemic treatment of acyclovir and ganciclovir combined with weekly intravitreal injections of ganciclovir and foscarnet. Retinitis resolved within 3 weeks and visual acuity improved. CMV retinitis can be associated with Good's syndrome.

Long-term follow up of thymus in patients with myasthenia gravis

We examined transversely the thymus of 33 myasthenia gravis (MG) patients followed up for more than 5 years and found three thymomas. One was found 21 years after thymoma resection (Masaoka I, WHO Type B2 thymoma) and extended thymectomy. The other two were non-thymomatous at onset, and they were not treated with extended thymectomy. Therapeutic guidelines should mention the importance of follow-up in MG thymus.