Cystic thymoma in a child: a rare case and review of the literature

Pediatric Thymoma: A Review and Update of the Literature

Pediatric thymomas are extremely rare and slow-growing malignant tumors. The recent publication of the first Union for International Cancer Control (UICC)/American Joint Committee on Cancer (AJCC) Tumor-Node-Metastasis (TNM) stage classification and updated treatment guidelines for thymomas has prompted us to perform a review of the literature on pediatric thymomas. A search of English-language articles in the PubMed, Cochrane, Web of Science, and Embase databases was conducted. Additional articles were identified through reference lists of retrieved publications. Thirty-two articles involving 82 pediatric thymomas were included. Males comprised 60% of patients, and 13% manifested myasthenia gravis (MG). Histotype B1 (45%) and stage I (52% Masaoka-Koga and 71% UICC/AJCC TNM) were the most frequent. Of note is the possibility that the lack of cases with mixed histologies in the reviewed publications might be related to a sampling issue, as it is well known that the more sections are available for review, the more likely it is that the majority of these neoplasms will show mixed histologies. Both staging systems showed a gradual increase in the percentage of cases, with more advanced stages of disease moving from type A to B3 thymomas. Complete surgical resection (R0) was the main therapeutic approach in Masaoka-Koga stage I (89%) and UICC/AJCC TNM stage I (70%) thymomas. Advanced stages of disease and incomplete surgical resection were most often associated with recurrence and death. An association between stage and outcome, and completeness of resection and outcome, was found. Interestingly, though an association between histotype and staging was found, this does not take into account the possibility of mixed histologies which would reduce the clinical impact of histologic subtyping over staging.

Multilocular thymic cyst (MTC) and other tumors with MTC features: Pitfalls in diagnosis

Cystic lesions of the anterior mediastinum represent a well-known group of benign lesions that are relatively common in the general practice, namely in the pediatric age group. In the adult population, multilocular thymic cyst (MTC) plays an important role in occurrence as it presents as a cystic anterior mediastinal mass that clinically may mimic another anterior mediastinal tumor. In general, MTC is of rather unusual occurrence and its histopathological features have been well described in the literature. However, similar histopathological features may also be associated with a gamut of other tumoral conditions that although unrelated may be encountered growing along the walls of these cystic structures. Herein a presentation of the classical MTC and the classical histopathological features of such entity in association with other tumoral conditions will be discussed. It is highly important to underscore that the final interpretation of some of these tumors is based on a thorough evaluation of the cystic lesion and a reasonable sampling for histological evaluation so that the proper interpretation can be reached. Needless to say, the radiological and clinical information of the patients with cystic anterior mediastinal lesions is very important in the final analysis of these cases.

Surgical management of thymic epithelial tumors in children: lessons from the French Society of Pediatric Oncology and review of the literature

PURPOSE

We report the results of a French multicenter retrospective study based on a period of more than 30 years and a review of the literature in order to more clearly define the surgical approach and specific pediatric risk factors.

METHODS

Clinical data of children comprising all histologic subtypes of thymic epithelial tumors (TET) treated between 1979 and 2009 in French pediatric oncology centers were retrospectively analyzed and discussed in the light of a review of all pediatric cases reported in the literature.

RESULTS

Nine cases were identified, corresponding to five females and four males with a median age of 13 years (range: 7.5-17). Histologic subtypes were type AB (n = 1), type B (n = 5) and type C (n = 3). Treatment consisted of tumor resection (4 R0, 4 R1, 1 R2) via right anterior thoracotomy, posterolateral thoracotomy, left thoracoscopy, sternotomy and cervicosternotomy, and/or chemotherapy, mainly cyclophosphamide-doxorubicin-cisplatin (CAP; n = 5), and/or radiotherapy (n = 4). Two patients with TET type C died. All other patients are alive with a median follow-up of 4 years (range: 1.5-20). Review of a total of 93 pediatric cases reported in the literature showed statistically significant associations between less favorable histologic subtypes and male gender (P = 0.012), advanced Masaoka stage (P < 0.001) and quality of resection (P < 0.001) respectively.

CONCLUSIONS

A review of the literature and our series identified several risk factors to take into account in the therapeutically decision. Complete resection through a sternotomy is highly recommended.

Pediatric thymomas: report of two cases and comprehensive review of the literature

PURPOSE

Thymomas are rare pediatric malignancies with indolent behavior. There are fewer than 50 reported cases and no comprehensive review. We sought to evaluate our recent experience with pediatric thymomas, and comprehensively review the extant literature.

METHODS

A systematic search of the PubMed database was performed using keywords: "thymoma", "pediatric", "juvenile", "childhood", and "child". Additional studies were identified by a manual search of the reference list.

RESULTS

We report two patients with thymomas. We identified 22 case reports or series that described 48 patients; 62 % were male, 15 % presented with myasthenia gravis. Fifty percent were Masaoka Stage I, 15 % were Stage II, 13 % were Stage III, and 23 % were Stage IV. Four patients with early stage (I or II) disease were treated with adjuvant therapies in addition to surgical excision, while five patients with late stage (III or IV) disease treated with surgical excision alone. Of studies reporting at least 2-year follow-up, survival was 71 %.

CONCLUSION

Pediatric thymomas are rare tumors with a slight male predominance. Wide variations were observed in the treatment of thymomas across all stages. Our review indicates a need for large database and multi-institutional studies to clearly elucidate clinical course, prognostic factors and outcome.

Thymomas in childhood: 11 cases from a single institution

AIM

Thymomas are rare in children. Our aim was to review clinical and pathologic characteristics and outcome in children with thymomas.

PATIENTS AND METHODS

Between 1979 and 2011, 11 children with thymomas were diagnosed. Hospital files were reviewed for presenting complaints, clinical, radiologic, and other laboratory data, surgical practices, chemotherapy and radiotherapy outcomes.

RESULTS

Median age was 8 years (range, 1 to 13 y). Male to female ratio was 9/2. Most common initial complaints were dyspnea, cough, chest pain, and fever. Median time from onset of symptoms was 1 month (range, 0.23 to 3 mo). Associated conditions including hyper-IgE syndrome, hypogammaglobulinemia, and systemic lupus erythematosus plus idiopathic thrombocytopenic purpura were present in 3 patients. Chest x-rays and/or thoracic computed tomographies displayed thymic hyperplasia and/or masses in anterior mediastinum accompanied by pleural (n = 2) and pericardial effusions (n = 1), pulmonary metastases (n = 1), and cervical lymph node metastasis (n = 1). Compression or invasion of trachea or vessels was documented in 5 cases. Seven cases underwent initial tumor resection; others experienced open or trucut biopsies. Histopathologically, 5 cases had invasive and 6 had benign thymomas. Benign thymomas did not receive any postoperative treatment; all cases are disease free at a median follow-up of 211 months. Three of 5 cases with invasive thymomas underwent surgery, 4/5 received chemotherapy and external radiotherapy (3600 to 4500 cGy). Two invasive thymomas died of disease. Three cases with invasive thymomas are disease free at a median follow-up of 209 months.

CONCLUSIONS

Benign thymomas have excellent prognosis. For invasive thymomas with or without metastasis, radiotherapy, and chemotherapy offers survival advantage. Complete surgical resection may increase chances for cure.

Invasive thymoma in a child: a rare case report

Thymomas are neoplasms of the anterior mediastinum and generally occur between the fourth and sixth decades of life. In children, they are rare, with few reported cases. We describe a 9-year-old boy with invasive thymoma treated successfully by surgery alone. The patient was previously healthy and under treatment for a community-acquired pneumonia. A chest radiograph showed an opacity at the left lung base, and thoracic computed tomographic scan showed a mass with thick walls and liquid content situated in the lingula with no cleavage plane with the mediastinum. The patient underwent a left anterolateral thoracotomy, which showed a mass extending from the anterior mediastinum, infiltrating the left upper lobe of lung, phrenic nerve, and pericardium. A left upper lobectomy and resection of the mediastinal mass and lymph nodes were carried out. The pathologic analysis showed it to be a type B3 fusiform-cell thymoma, infiltrating the left upper lobe and 1 peribronchial lymph node. A multidisciplined tumor group decided to observe the patient and followed with thoracic computed tomographic scans every 3 months. After 2 years of follow-up, the patient has no evidence of recurrent disease.

Thymoma in children: report of 2 cases and review of the literature

Thymoma is an uncommon and slow-growing neoplasm. It is derived from thymic epithelial cells and comprises about 20% to 30% of mediastinal masses in adults, but only about 1% in pediatric patients. Patients usually present with mass-associated respiratory symptoms, superior vena cava syndrome, or paraneoplastic syndrome including myasthenia gravis, pure red cell aplasia, or acquired hypogammaglobulinemia, and connective tissue disorders. Due to the limited number of cases, knowledge, and experience with thymoma in pediatric patients, the diagnosis and treatment are very challenging for this age group. In this article, we report 2 cases of thymoma in childhood and provide a comprehensive review and analysis of the reported pediatric cases in the past 30 years (total of 32 cases). We found that patients younger than age 10 years were predominantly male (M:F = 6:1) and had advanced tumor stage more frequent than patients older than age 10 (P = .03). There were also significant associations of male sex with more advanced tumor stage and less favorable outcome (P = .03). These findings suggest that age and sex may be additional potential prognostic contributors in pediatric patients with thymoma. The clinicopathologic features, differential diagnosis, and current therapeutic recommendations of this uncommon tumor in pediatric patients are also addressed.