1/8. Ring chromosome 6 may represent a cytogenetic subgroup in benign thymoma.Cytogenetic and fluorescence in situ hybridization analysis of a thymoma revealed the presence of an abnormal clone with a karyotype 46,XY,r(6)(p2?q35?).ish r(6)(p2?q35?)(WCP6 ,dJ476O18-,dJ62I11-, PAC59C23 ,PAC57H24-),der(21)t(6;21)(p25;q22)(dJ62I11 ,cosC9a1-). Histologically, the tumor was encapsulated and classified as thymoma type AB (world health organization classification) or mixed thymoma (Muller-Hermelink classification), composed of well-formed lobules with sharp demarcation of both the spindly type A and lymphocyte-rich type B components. This finding, together with literature data, strongly suggests that terminal deletion of the short arm of chromosome 6 is a recurrent aberration in thymoma.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
2/8. A case of Epstein-Barr Virus (EBV)-associated thymic carcinoid and investigation of existence of EBV-infected cells in thymus and thymic tumors.We describe the first case of Epstein-Barr virus (EBV)-associated thymic carcinoid tumor found by in situ hybridization (ISH) on paraffin-embedded sections. ISH revealed that both tumor cells and infiltrated lymphocytes were EBV positive, while a few EBV-infected lymphocytes were detected in 2 of 11 thymuses and 1 of 11 thymomas.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
3/8. Malignant lymphoma of mucosa-associated lymphoid tissue arising in the thymus of a patient with sjogren's syndrome. A morphologic, phenotypic, and genotypic study.A 59-year-old woman with sjogren's syndrome had an anterior mediastinal tumor. The tumor had epithelium-lined thymic cysts. Histologically, centrocyte-like (CCL) cells were present as clusters intermingling with small lymphocytes and plasma cells, invaded the epithelium, and formed characteristic lymphoepithelial lesions; the tumor was identified as malignant lymphoma arising in mucosa-associated lymphoid tissue (MALT). Within the tumor, trapped Hassall's corpuscles were recognized. Immunohistochemical staining demonstrated monotypic cytoplasmic kappa light chains in a small portion of the CCL cells. Furthermore, Southern blot hybridization studies showed rearrangements of immunoglobulin heavy chain, immunoglobulin kappa light chain, and T-cell receptor beta genes. The findings are consistent with thymic low-grade B-cell MALT lymphoma.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
4/8. Mucosa-associated lymphoid tissue lymphoma of the thymus: a case report with no evidence of MALT1 rearrangement.We report a case of thymic mucosa-associated lymphoid tissue (MALT) lymphoma (TML) that presented as an asymptomatic mediastinal mass in a 40-year-old woman with a past history of Sjogren syndrome. This case had the characteristic clinical and pathological features of TML, as found in most of the 24 previously reported cases, i.e., autoimmune context, especially Sjogren syndrome, IgA secretion, large epithelial cysts, lymphoepithelial lesions involving residual Hassal's corpuscles, epithelial cysts, and a marked plasmacytic differentiation with IgA expression. Reverse-transcription polymerase chain reaction for t(11;18)(q21;q21) was negative, in agreement with recently published data. In this case, investigation for t(14;18)(q32;q21) using fluorescent in situ hybridization was also performed and supplied negative results. Neoplastic cells were negative for MAL, a marker of primary mediastinal large B cell lymphoma (PMBL). Altogether, these findings further support that among MALT lymphomas, TML have peculiar clinical and morphological characteristics and appear not to involve MALT1 rearrangement. They also suggest the absence of a relationship between TML and PMBL.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
5/8. Thymic carcinoma. Report of five cases and review of the literature.Among 54 mediastinal tumours we examined in the past 20 years, there were 5 cases of primary thymic carcinomas, each with widespread metastases. Histological features in three cases were consistent with lymphoepithelioma-like carcinoma. One case showed an epidermoid pattern with keratotic pearls resembling Hassall bodies. One undifferentiated carcinoma developed from a cortical thymoma. Epstein-Barr virus could not be detected in tumour tissue with in situ hybridization. A review of the literature revealed only 94 well-documented cases of thymic carcinoma. Both thymic carcinomas and thymomas are neoplasms of the thymic epithelial cells, but thymic carcinomas are obviously histologically malignant and usually not associated with any parathymic syndromes. Epidermoid and lymphoepithelioma-like carcinomas are described along with special forms, such as small- and clear-cell carcinomas, basaloid, sarcomatoid, mucoepidermoid, and adenocystic carcinoma. Compared to the other forms, lymphoepithelioma-like carcinoma has a poor prognosis in regard to metastases and rate of survival. Some thymic carcinomas may develop from pre-existing thymomas.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
6/8. EBER-1 expression in thymic carcinoma.The Epstein-Barr virus-encoded small nuclear rna, EBER-1, has been shown to be a suitable target for the in situ hybridization detection of EBV in routinely processed tissue specimens. We evaluated the presence of EBV in thymic carcinoma and invasive thymoma using EBER-1 in situ hybridization on formalin-fixed paraffin-embedded tissue sections. EBER-1 expression was demonstrated in a case of lymphoepithelioma-like thymic carcinoma, but was not detectable in other thymic carcinomas including six squamous cell carcinomas, a clear cell carcinoma and seven invasive thymomas. As reported in three previous cases of EBV-associated thymic carcinoma, lymphoepithelioma-like thymic carcinoma was shown to be closely associated with EBV in our series.- - - - - - - - - - ranking = 2keywords = hybridization (Clic here for more details about this article) |
7/8. Expression of prohormone convertase, PC2, in adrenocorticotropin-producing thymic carcinoid with elevated plasma corticotropin-releasing hormone.An autopsy case of ACTH-producing thymic carcinoid with Cushing's syndrome is reported. The patient was a 63-yr-old man with multiple bone metastases from an undetermined primary site. hyperpigmentation was observed at the terminal stage. The plasma levels of ACTH, cortisol, chromogranin a, and urinary 17-hydroxy-corticosteroids were extremely high, and ectopic ACTH-producing neuroendocrine tumor was diagnosed. In addition, plasma CRH was high. autopsy revealed that the patient had primary thymic carcinoid with extensive metastases. Remarkable hyperplasia of the adrenal cortexes and Crooke's hyaline degeneration of the pituitary gland were consistent with Cushing's syndrome by ectopic ACTH production. There were multiple CRH-producing cells without degenerative changes in the hypothalamus. The tumor cells were immunoreactive to ACTH, CRH, and the cleavage enzyme PC2. POMC messenger ribonucleic acid and PC2 messenger ribonucleic acid were detected in the tumor cells by an in situ hybridization method. Expression of PC2 was considered to induce hyperpigmentation by producing alpha MSH. Despite hypercortisolism and ectopic production of CRH by the tumor cells, hypothalamic CRH cells were not atrophic. This case is a good example to demonstrate the correlation between CRH and the hypothalamo-pituitary-adrenal axis as well as hyperpigmentation in Cushing's syndrome.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |
8/8. Treatment of pediatric malignant thymoma: long-term remission in a 14-year-old boy with EBV-associated thymic carcinoma by aggressive, combined modality treatment.Malignant thymoma, including thymic carcinoma, is extremely uncommon in the pediatric population. It is known to have a very poor outcome. We report on a 14-year-old boy with Epstein-Barr virus (EBV)-associated thymic carcinoma. Sections of the original tumor were analyzed for EBV by in situ hybridization to confirm the histological diagnosis of a lymphoepithelioma-like subtype. High copy numbers of EBV rna were detected in the tumor tissue, suggesting an etiological role of EBV in our case. Intensive treatment resulted in long-term remission over 12 years. In order to facilitate the difficult management of the rare child with malignant thymoma, a literature search was initiated. Forty well-documented pediatric cases of malignant thymoma were found in the literature. Histological characteristics, clinical features, and therapeutic regimens were reviewed. Having the very limited experience with malignant thymoma in childhood in mind, it is concluded that its aggressiveness makes the most intensive treatment necessary. Long-term remission can be achieved by application of radical surgery, high-dose irradiation, and multiagent chemotherapy. The combination of cisplatinum, etoposide, and ifosfamide seems to be promising.- - - - - - - - - - ranking = 1keywords = hybridization (Clic here for more details about this article) |