Epithelial Thymoma Research Articles

Minimally invasive thymectomy: the best option for early and locally advanced epithelial thymomas

Minimally invasive thymectomy: the best option for early and locally advanced epithelial thymomas

Carcinoma Showing Thymus-Like Differentiation (CASTLE): A Rare Tumor of the Thyroid

Carcinoma showing thymus-like differentiation (CASTLE) is a rare neoplasm of the thyroid or the adjacent tissues in the neck. It was first described by Miyauchi et al. in 1985 as an intrathyroidal epithelial thymoma. In 1991 Chan and Rosai classified these tumors into four types including CASTLE. World Health Organization (WHO) declared it as an independent clinicopathologic entity in 2004. The tumor arises from ectopic thymus tissue or remnants of branchial pouch. Both sexes are affected similarly with a slight female dominance. It is usually encountered in the fourth and fifth decades of life. It does not have specific symptoms or radiologic findings which makes preoperative diagnosis difficult. It has a higher tendency to be located in the lower poles of thyroid lobes. Immunohistochemistry helps differentiate it from other malignant neoplasms, CD5 being an important marker. The tumor is negative for thyroid specific markers as thyroglobulin, TTF-1 or calcitonin. Surgery is considered the mainstream therapy. Radiotherapy may be reserved for gross disease or recurrence. The role of chemotherapy is unclear. The prognosis of CASTLE is favourable.

Rare presentation of ectopic thymoma

Thymoma is the most common tumor of the anterior mediastinum with an incidence of 0.15 cases per 100,000. Ninety percent of all thymoma occur in the anterior mediastinum, with the remainder occurring in the neck or other mediastinal areas. 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. ECTs are often confused with thyroid or parathyroid swellings due to their anatomical positioning. Intrathyroid epithelial thymoma is a rare tumour comprising about 0.08% of all primary thyroid malignancies. It is low-grade thyroid carcinoma with squamous cell differentiation whose overall survival rate was found to be 71%. Here we presented a case of 43 year old female, came with swelling in front of the neck since many years. Ultrasound neck and fine needle aspiration cytology (FNAC) was performed. Patient underwent total thyroidectomy and specimen obtained was sent for histopathological examination. It revealed ectopic intrathyroid thymoma.

Effects of chicken anaemia virus on experimental leukosis, induced by avian myelocytomatosis virus Mc29

The effects of concomitant infection with chicken anaemia virus (CAV) on the incidence, clinical manifestation and mortality from leukosis, induced by the avian myelocytomatosis virus strain Mc29 were studied. Experimental one-day-old 15 I line White Leghorn chickens were inoculated simultaneously with Mc29 and CAV or with Mc29 alone and observed daily for clinical signs and mortality. Both groups of chickens inoculated with Mc29 virus strain alone or in combination with CAV deve­loped tumours and died within 57 days. Necropsy has been performed on all dead birds following the standard protocol. Organ samples from thymuses, spleens, bone marrow, and livers were collected and histopathologically investigated. Neoplasms detected included myelocytomas, nephroblastomas and hepatocellular carcinomas. In addition, 50% of the CAV/Mc29-inoculated chickens developed epithelial type thymomas. However, no such lesions were found in chickens infected with Mc29 alone. No significant differences in the clinical course of leukosis between the two experimental groups of chickens were observed. The results indicated that CAV infection did not affect substantially the incidence and mortality from avian leukosis, induced by myelocytomatosis virus strain Mc29, but contributed to greater variety of the induced tumours.

Image-based ex vivo drug screen to assess targeted therapies in recurrent thymoma

ObjectivesThymoma is a rare malignancy derived from the thymic epithelial cells. No standard salvage treatments are available for recurrent thymoma and due to the low number of cases, alternative treatment regimens have been assessed only in small case series with varying success. The aim of this study was to use an image-based ex vivo drug screening strategy to assess efficacy of a large panel of anti-cancer agents for thymoma using patient derived tumor cells. Materials and MethodsVital tumor and tumor associated cells were used to assess the efficacy of 147 anti-cancer drugs including approved and experimental agents. Drug efficacy was analyzed at single cell resolution using image-based high content drug screening to assess tumor cell specific responses. Molecular profiling and histopathology was used to confirm the drug targets identified by the screen. ResultsThe ex vivo drug screen identified selective sensitivity of the cancerous epithelial thymoma cells to EGFR-, HDAC- and mTOR-inhibition. Histopathology confirmed high protein level expression of EGFR in the patient’s tumor. Patient was initiated treatment with Cetuximab resulting in stable disease after relapse on five different chemotherapy regimens. ConclusionThe results show that the image-based ex vivo therapy efficacy screening strategy can be used to identify patient and tumor relevant drug sensitivity patterns in thymoma. The results also warrant continued research on EGFR as a biomarker and therapy target in recurrent thymomas.

Histological Classification of Thymoma

Background: Many thymoma classifications have been followed and have been updated by newer or alternative schemes. Many classifications were based on the morphology and histogenesis of normal thymus as the backbone, while other classifications have followed a more simplified scheme, whereby thymomas were grouped based on biological behavior. The WHO classification is currently the advocated one, which is based on “organotypical” features (i.e. histological characteristics mimicking those observed in the normal thymus) including cytoarchitecture (encapsulation and a “lobular architecture”) and the cellular composition, mostly the nuclear morphology is generally appreciated.
 Objectives: This study aims to re-classify thymomas by establishing certain morphometric parameters to evaluate the epithelial cells nuclei. An appraisal of thymoma classification as cortical/ lymphocytic/ type B1 and B2 or medullary/ spindle cells/ type A will be attempted as objective re-evaluation of thymoma.
 Patients: This study is a retrospective evaluation of 50 cases of thymoma, 20 cases of thymic hyperplasia and 10 cases of normal thymus (control group). Using a 5 µm formalin-fixed paraffin embeded tissue sections, stained with hematoxylin-eosin stain, these cases were previously classified histologically into lymphocytic (6 cases), lymphoepithelial (mixed) (28 cases) and epithelial (16 cases), including 2 cases of spindle cell thymoma.
 Methods: Computer-assisted morphometry was performed for 80 cases. This involves digitization of the histopathological features and application of morphometric analysis through software. The morphometric parameters used are nuclear area, maximum nuclear diameter and Form factor of epithelial cells nuclei. Ten normal thymus glands from the archived cases were also evaluated as a control groups.
 Results: The results showed that epithelial thymomas possess significantly different nuclear areas from that of a normal thymus, the maximum nuclear diameter (D-Max) follows the same pattern and adds no further outcomes. The numerical morphometric analysis showed no significant differences between lymphocytic predominant thymoma and those classified as cortical thymoma (Type B2). Thus it does not support such a re-classification. Form factor is an indication of pleomorphism, but it should be cautiously used when spindle cells are present since it may give a false indication of pleomorphism.
 Conclusion: Computer-Assisted morphometric analysis provides an objective, reproducible and comparable results for thymoma histological classification.
 Keywords: Thymoma, Histological classification, Grading, Morphometry, Computer-assistedmorphometry.

Low prevalence of Merkel cell polyomavirus in human epithelial thymic tumors.

BackgroundThe etiology of thymic epithelial tumors is unknown. Murine polyomavirus strain PTA has been shown to induce thymomas in mice. Recently, using diverse molecular techniques, we reported the presence of human polyomavirus 7 (HPyV7) in thymic epithelial tumors. In the present study, we investigated the prevalence of Merkel cell polyomavirus (MCPyV) in thymic epithelial tumors.MethodsThirty‐six thymomas were screened for MCPyV by PCR and subsequently tested by DNA and RNA in situ hybridization and immunohistochemistry. Twenty‐six thymomas were diagnosed with myasthenia gravis (MG).ResultsMCPyV DNA was detected by PCR in 7 (19.4%) of the 36 thymic epithelial tumors and in six of these, the presence of MCPyV was confirmed by fluorescence situ hybridization. Of these, 3 (28.6%) revealed weak MCPyV LT‐antigen protein expression. In addition, one of the MCPyV positive thymomas tested positive for MCPyV LT RNA with RNAscope. Of interest, two out of the three thymomas that previously tested positive for MCPyV by immunohistochemistry also tested positive for HPyV7. One of the 11 MG‐negative and 2 of the 25 MG‐positive were positive for MCPyV.ConclusionsMCPyV DNA and MCPyV protein expression can be detected in human epithelial thymoma; however, to a far lesser extent than HPyV7. Our data strongly indicate that because of its infrequent detection and weak expression, MCPyV is unlikely to play an important role in the etiopathogenesis of human thymomas.

Clinical, Neurophysiological and Immunological Peculiarities of Myasthenia Gravis in Patients with Different Histologic Types of Thymoma

Thymoma is characterized by various clinical manifestations. About half of them are manifested as an asymptomatic course, others occur in a combination with different syndromes. 25% of patients develop compression of tumor blood vessels, nerves and organs of the mediastinum or clinical signs of germination of thymic tumor in other organs. 40% of patients are diagnosed with autoimmune diseases due to dysfunction of the thymus. Generalized myasthenia gravis (75%) is most frequently observed.The objective of the research was to study clinical and immunological peculiarities of myasthenia gravis depending on the size and histological type of thymoma.Materials and methods. The results of clinical and immunological, instrumental and histological examination of 30 patients with myasthenia on the background of thymoma were analyzed. The severity of the disease was assessed using clinical classification of the Myasthenia Gravis Foundation of America (MGFA, 2001).To determine the barrier function of phagocytic cells, phagocytosis activity of neutrophils was evaluated using the light microscope. The phagocytic index, the phagocytic number and the index of phagocytosis completion were determined. The suspension culture of Saccharomyces cerevisiae was used as a microbial agent. Preparations were stained using the Romanovsky-Himze methods. Neutrophilic leukocytes were separated from leukocyte suspension of peripheral blood. The expression of differentiation clusters CD3+, CD4+ and CD8+ on subpopulation of T- and B-cells were evaluated by indirect ELISA using monoclonal antibodies labeled with FITC-dye. To diagnose thymoma, we used spiral CT “Marconi” SeleCT/SP. For histologic study thymoma samples were fixed in 10% neutral formalin for 24 hours. The material was embedded in paraffin after posting through the chloroform in the usual way; then, sections with the thickness of 5-7 μm were prepared. Preparations were stained with hematoxylin and eosin.Results and conclusions. The severity of the clinical course of myasthenic syndrome on the background of thymoma does not depend on tumor size; it depends on the histologic type and immunological imbalance. The severest clinical picture was observed in patients with type AB thymoma and the least severe course of myasthenic symptoms was found in patients with lymphoid thymoma (type B1). Lymphoepithelial and epithelial thymomas were accompanied by similar immunological disorders. The reduction in the levels of CD3+ and CD4+ lymphocyte subpopulations can be used as a reliable diagnostic criterion. Lymphoid thymomas are characterized by a significant reduction in the indicators of the phagocytic index, the phagocytic number, and the level of CD8+ lymphocyte subpopulations as well as an increase in the level of CD4+ subpopulations. Surgical treatment as a method of choice in case of radical immunosuppression is indicated for all patients with confirmed thymoma regardless of its size and histological characteristics.

Intrathyroid epithelial thymoma (ITET) and carcinoma showing thymus-like differentiation (CASTLE): CD5-positive neoplasms mimicking squamous cell carcinoma of the thyroid.

Carcinoma of possible thymic epithelial origin may occur within the thyroid gland, which was first reported by Miyauchi et al. as intrathyroid epithelial thymoma (ITET). ITET is a rare tumor comprising about 0.08% of all primary thyroid malignancies. It is a low-grade thyroid carcinoma with squamous cell differentiation whose overall survival rate was found to be 71%. Lymph node metastasis at surgery was found in 40% and hematogenous metastases developed in bones, liver and lungs. This tumor grows within the thyroid gland and invades into the thyroid parenchyma as well as into the extrathyroid structures. It is a well-circumscribed solid tumor with a sharp tumor border, but is not capsulated. After fixation, the cut surface of the tumor is gray-white in color and is a solid tumor with lobulation. Tumor calcification was not detected in our 15 cases. The tumor cells show solid sheets of growth with occasional keratinization without follicular or papillary structures. Lymphocytic infiltration in the stroma is one of the most characteristic features of this tumor. The tumor cells are polygonal epithelial cells with distinct nucleoli and ill-defined cell border. Positive immunoreactivity for CD5 is a key feature to differentiate it from undifferentiated carcinoma, poorly differentiated carcinoma, medullary (C cell) carcinoma and high-grade squamous cell carcinoma (so-called primary squamous cell carcinoma) of the thyroid. Negative immunoreactivity for calcitonin, TTF1 and thyroglobulin, and positive immunoreactivity for p63 and KIT are also helpful for differential diagnosis. Nuclear atypia is mild and mitoses are less frequent, with an intermediate proliferation index (MIB-1 labeling index is usually less than 20%), which are also helpful to differentiate it from high-grade primary squamous cell carcinoma of the thyroid. The tumors in our 15 cases demonstrate 3 histological subtypes: keratinizing squamous cell carcinoma type, non-keratinizing basaloid cell carcinoma (lymphoepithelioma-like) type and neuroendocrine carcinoma type, which correspond to subtypes of the mediastinal thymic carcinomas.

A prospective, phase II trial of induction chemotherapy with docetaxel/cisplatin for Masaoka stage III/IV thymic epithelial tumors.

7104 Background: Thymic epithelial tumors (TETs), thymoma and thymic carcinoma, are the most common tumor of the anterior mediastinum. Initial complete resection is the most powerful prognostic indicator of survival. However, it is obviously related to stage. Here, we report the result of a prospective phase II study of neoadjuvant docetaxel/cisplatin in patients with locally advanced TETs. Methods: In this open-label, phase II, nonrandomized study, patients with histologically proven, Masaoka stage III/IV TETs at presentation were enrolled. Patients received docetaxel 75mg/m2 I.V for 1 hr, followed by I.V cisplatin 75mg/m2 over 1.5hr on day 1 of every 3 week. After 3 cycles of chemotherapy, subsequent surgical resection was performed, if resectable. Results: From March 2007 to July 2011, a total of 27 TETs patients were entered into the trial. The median age was 54 (range, 15-68), and Masaoka stage at presentation was III (n=8, 29.6%), IVA (n=17, 63.0%), and IVB (n=2, 7.4%). Histologic type by the WHO includes type B1 (n=2, 7.4%), B2 (n=3, 11.1%), B3 (n=5, 18.5%), and thymic carcinoma designated as type C (n=16, 59.3%). After completion of neoadjuvant chemotherapy, 17 (63.0%) achieved PR and 10 (37.0%) had SD. Nineteen patients (70.4%) underwent surgical resection, and 8 patients did not (surgeons’ decision, n=5; patients’ refusal, n=2; radiation therapy, n=1). Of the 19 patients undergoing surgical resection, 17 (89.5%) had complete resections and 2 (10.5%) did not. Major side effects of chemotherapy include grade 3 anorexia (n=1), nausea (n=2), diarrhea (n=3), alopecia (n=1). After completion of surgical resection, adjuvant therapy was performed as follows: radiotherapy (RT, n=8), chemotherapy (CTx, n=6), radiotherapy with chemotherapy (RT + CTx, n=2) and observation (n=3). Overall, 4yr OS and PFS was 79.4% and 40.6%. Patients with complete resection showed 93.8% of 4yr OS and 50.2% of 4yr PFS whereas patients without complete resection showed 47.6% of 4yr OS and 26.7% of 4yr PFS, respectively (OS, p=0.06; PFS, p=0.27). Conclusions: Neoadjuvant docetaxel/cisplatin was well tolerated and feasible, and improved the surgical respectability in patients with advanced TETs.

Proteasome subunit β5t expression in cervical ectopic thymoma

Cervical ectopic thymoma is extremely rare, and, till date, <30 cases have been reported in the literature.1 Although typical cases of thymic neoplasms show distinctive morphology, they may pose diagnostic...

A case of thymoma detected by 18F-choline positron emission tomography/computed tomography

Positron emission tomography/computed tomography (PET/CT) with choline, labelled with nuclides like C or F, is an important diagnostic tool in the management of oncologic diseases with low glucose metabolism and is currently employed in patients with prostate cancer (PC) [1, 2]. A 60-year-old man in restaging of PC underwent Fcholine PET/CT because of increased serum prostatespecific antigen (PSA) levels (2.25 ng/ml) and a bone scan suspicious for metastases 1 year after radical prostatectomy. The patient had not received hormone therapy in the 2 months previous to the exam date. No lymph node or bone metastases were detected on F-choline PET/CT. PET images showed prominent uptake in the mediastinum (a), with a maximum standardized uptake value (SUVmax) of 8. Fused PET/CT and CT views clearly showed that accumulation corresponded to a welldefined, non-homogeneous area of 6 cm with calcifications in the upper mediastinum (b, b’, c, c’). The patient did not suffer any symptoms related to a “mediastinal mass” prior to performance of the exam. Subsequently histopathological analysis, after a CTguided biopsy, diagnosed epithelial thymoma. Is known that proliferation of benign cellular types such as lymphocytes may be responsible for increased choline uptake in benign diseases such as phlogosis [3]. F-FDG PET/CT enables accurate preoperative evaluation of mediastinal masses, especially considering SUVmax as an indicator of malignant behaviour [4], but no data have been reported about choline uptake in thymoma. In clinical practice nuclear physicians cannot exclude the possibility of abnormal uptake of choline, not related to PC, in some oncologic and non-oncologic conditions. Knowledge of CT findings is important; the histological exam still remains the most important step for diagnosis.

Ectopic cervical thymoma mimicking as papillary thyroid carcinoma: A diagnostic dilemma

Ectopic cervical thymomas are often confused with thyroid or parathyroid swellings due to their anatomical positioning. Predominant epithelial thymoma can be misdiagnosed as papillary thyroid carcinoma on fine needle aspiration and lymph node metastasis of epithelial tumor on frozen section. Predominantly lymphocytic thymomas have often been misinterpreted as Hashimoto's thyroiditis or malignant lymphoma, either by fine needle aspiration or on frozen section analysis. If cytology is doubtful and is not correlating with clinical, anatomical and surgical findings; immunohistochemistry is a very important tool in such cases to give final answer. Thyroid cell specific proteins such as thyroglobulin, thyroid transcription factor-1, thyroperoxidase and dipeptidyl aminopeptidase-4, neuroendocrine markers chromogranin, calcitonin and parathyroid hormone could be used to rule out thyroid or parathyroid origin. We present such rare case of ectopic cervical thymoma mimicking as papillary thyroid carcinoma.

Aplastic anaemia as an autoimmune complication of thymoma

A 47-year-old woman was evaluated for progressive, transfusion-dependent thrombocytopenia and anaemia. Examination showed decreased breath sounds on the right. Computed tomography of the thorax demonstrated a heterogeneous, hypervascular mass occupying the right hemithorax (top). Bone marrow biopsy (bottom left) was hypocellular (20%), with scant haematopoietic elements, interstitial aggregates of T-lymphocytes by CD3 immunostaining, and increased suppressor T cells (CD4:CD8 ratio 1:5) by flow cytometry. T cells were not monoclonal by T-cell-receptor gene rearrangement assays. Resection of the intrathoracic mass showed a 14 · 11 · 9 cm pedunculated tumour arising in the anterior mediastinum, diagnosed as an epithelial (spindle cell) thymoma (bottom right). She remained transfusion-dependent and developed severe neutropenia. Anti-thymocyte globulin, ciclosporin and mycophenolate mofetil were administered without response. Refractory pancytopenia persisted despite treatment with alemtuzumab. The patient died of infectious complications 7 months after her diagnosis. Aplastic anaemia was probably induced by auto-reactive T cells originating in the giant thymoma.

Periodic Myoclonus Due to Cytomegalovirus Encephalitis in a Patient With Good Syndrome

Good syndrome (GS) refers to a constellation of thymoma and adult-onset immunodeficiency characterized by low or absent B cells, hypogammaglobulinemia, and variable defects in cell-mediated immunity with an inverted CD4/CD8(+) T-cell ratio. Patients may develop severe or chronic infections as a result of this immunodeficiency. To describe a patient with GS who developed cytomegalovirus (CMV) encephalitis and showed a periodic electroencephalographic pattern and myoclonus. Case report. Outpatient neurology clinic at a university medical center. Patient A 64-year-old man who developed periodic myoclonus involving the right half of his body and the left arm. Five years previously, the patient had undergone resection of a pathologically confirmed epithelial thymoma. Quantitative CMV polymerase chain reaction of the serum and cerebrospinal fluid showed strongly positive results (1:10 000), allowing the diagnosis of CMV encephalitis. To the best of our knowledge, myoclonus and periodic electroencephalographic pattern have not previously been reported in CMV encephalitis. Opportunistic CMV infection should be considered early in the evaluation of patients with GS or a history of thymoma who develop unusual neurological symptoms.

Clinicopathologic Significance of Intrathyroidal Epithelial Thymoma/Carcinoma Showing Thymus-like Differentiation

Intrathyroidal epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE) is a rare malignant tumor having histopathologic features similar to those of squamous cell carcinoma of the thyroid and other organs and a more favorable prognosis. It is thought to originate from ectopic thymic tissue or embryonic thymic rest in or adjacent to the thyroid. We investigated clinicopathologic features of 25 cases of ITET/CASTLE. The sensitivity and specificity of the pathologic diagnosis of ITET/CASTLE by immunohistochemical staining with CD5, a marker of carcinoma of thymic origin, were 82% and 100%, respectively. The 5- and 10-year cause-specific survival rates were 90% and 82%, respectively. Nodal metastasis and tumor extension predict a worse prognosis. Of 22 patients who had curative surgery, 10 (45%) underwent adjuvant radiation therapy, and no locoregional recurrence was seen in any of them. This is the first study demonstrating the survival curve for patients with ITET/CASTLE. Our findings suggest that curative resection followed by radiation therapy may effectively prevent locoregional recurrence and CD5 immunostaining is useful for diagnosing ITET/CASTLE.

Usefulness of S100A9 for diagnosis of intrathyroid epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE)

Intrathyroid epithelial tumour (ITET)/carcinoma showing thymus-like differentiation (CASTLE) is a rare malignant tumour, which is thought to originate from ectopic thymic tissue in the thyroid. The differential diagnosis between ITET/ CASTLE and squamous cell carcinoma (SCC) or undifferentiated carcinoma with squamoid component (UC-SCC) is very important, because ITET/CASTLE shows a far better prognosis than SCC or UC-SCC. In this study, we investigated the usefulness of S100A9, a marker of SCC and squamous cell epithelia, for diagnosis of ITET/CASTLE. We immunohistochemically investigated S100A9 expression in 23 ITET/CASTLEs, 26 SCCs, and 19 UC-SCCs, as well as eight thymomas and 12 normal thymic tissues. All thymomas and thymic tissues showed a small number of S100A9-expressing cells in a scattered pattern in accordance with Hassall corpuscles. Twenty-one of 23 ITET/ CASTLEs showed the same pattern as thymomas or thymic tissues, while 14 SCCs and 15 UC-SCCs showed diffuse and laminated positivity of S100A9. The positive predictive value and specificity of S100A9 for diagnosis of ITET/CASTLE was 91.3 and 93.9%, respectively, and sensitivity was 75.0%. These findings suggest that S100A9 is a useful marker for discriminating ITET/CASTLE from SCC or UC-SCC.

Malignant transformation of thymoma in recipient rats by heterotopic thymus transplantation from HTLV-I transgenic rats

Transgenic rats expressing the pX gene of human T lymphocyte virus type-I (HTLV-I) under control of the rat lymphocyte-specific protein tyrosine kinase type-I promoter (lck-pX rats) developed benign epithelial thymomas. When the thymuses of newborn lck-pX rats were transplanted into the subcapsular space of the kidney in other thymectomized lck-pX rats, similar tumors developed in the transplanted thymuses. Following the tumor growth, dissemination in the abdominal cavity and distant metastasis occurred. The tumors were histopathologically similar to the original thymomas, but prominent nuclear atypia and high mitotic activity were present. The Ki-67 index was twice as high as that in the originals. The tumors were transplantable into the subcutis of lck-pX rats, although transplantation of the originals never succeeded. All evidence indicated that malignant transformation of thymoma was induced by the heterotopic transplantation. Expression of the pX transgene in the transformed tumors were significantly reduced. Among host genes, the expression of p16ink4a/ARF, which was significantly upregulated in the originals, was never detected in the transformed tumors. Genomic Southern blots and PCR suggest that homozygous deletion of the p16ink4a/ARF gene may play important roles in malignant transformation in this model. Our model described here is a useful unique model for in vivo malignant transformation.

Metastatic thymoma to the peritoneum: A case report

Summary Thymomas usually consist of mostly benign histology, yet their malignant potential and distant metastasis remains unpredictable. Extrathoracic distant metastasis of malignant thymomas to the peritoneum are rare and only two cases are noted in the literature. We report a third case of diffuse intraperitoneal metastasis from an epithelial cell-based thymoma of the mediastinum. Metastasis to the peritoneum occurred 3 1 2 years after the initial diagnosis. Our case is noted for its aggressive behavior and relatively short interval of distant metastasis to the peritoneum despite four different chemotherapeutic regimens and radiation therapy.

Tumor recurrence at thoracostomy tube insertion sites: A report of two pediatric cases

Recurrence of thoracic malignant tumors at port sites used for thoracoscopic procedures in adults have been described. However, there are no reports of tumor recurrence at thoracostomy tube or thoracoscopic trocar insertion sites after operation for thoracic malignancies in children. The authors report 2 cases of tumor recurrence at thoracostomy tube insertion sites after intraoperative gross spillage of pleuropulmonary blastoma and malignant epithelial thymoma and discuss approaches that may potentially prevent this devastating complication.