1/35. Two cases of ectopic hamartomatous thymoma.Ectopic hamartomatous thymoma (EHT) is a rare benign neoplasm. Since it was named by Rosai et al. in 1984, 24 cases have been reported. We herein report two cases of EHT, one of which presented with massive myoid cells, and review the literature related to EHT. Both of our cases displayed the typical features of EHT: (1) nests of epithelial cells, including solid, cystic, or glandular epithelial islands; (2) spindle cells dominating the microscopic picture; and (3) adipose cells which intermingle haphazardly to impart a hamartomatous quality to the tumor. In this paper, we observed massive myoid cells and the transition from spindle epithelial cell to myoid cell in one of our cases. Immunohistochemical examinations showed that the main component of EHT, spindle cells, was positive for cytokeratin and epithelial membrane antigen (EMA). Intriguingly, the myoid cells simultaneously expressed cytokeratin, EMA, myoglobin, and creatine kinase-mm, suggesting that myoid cells may originate from epithelial cells and are an intermediate state between epithelial cells and muscular cells.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/35. thymoma associated with pure red cell aplasia, immunoglobulin deficiency and an inhibitor of antigen-induced lymphocyte transformation.A case of thymoma associated with pure red cell aplasia and hypogammaglobulinaemia is described in which the anaemia was of abrupt onset, following removal of the tumour. Tests of immunological function showed abnormalities of both humoral and cellular immunity. The patient was found to have a serum inhibitor of antigen-induced lymphocyte transformation which disappeared after immunosuppressive therapy at the same time that erythroblasts reappeared in the marrow. It is suggested that the triad of thymoma, pure red cell aplasia and immunoglobulin deficiency are manifestations of 'pluripotent' stem cell failure; in this case the inhibitor of lymphocyte transformation may have been related to the factor which also inhibited red cell maturation.- - - - - - - - - - ranking = 5keywords = antigen (Clic here for more details about this article) |
3/35. Loss of cytomegalovirus-specific immunological memory in a patient with thymoma.cytomegalovirus (CMV) retinitis is a re-activation infection associated with severely impaired T cell-mediated immunity. We describe a patient with long-standing Crohn's disease and thymoma who developed severe CMV retinitis. While thymoma can be associated with impaired humoral immunity and a quantitative CD4 T helper cell deficiency, these were not evident in our patient. However, more detailed investigation of anti-CMV responses showed absence of specific T cell responses to CMV antigen. Normal CMV seropositive controls have detectable proliferation and interferon-gamma production by T cells in response to stimulation with CMV antigen, but this was absent in this patient both during the acute infection and in convalescence. Other measures of T cell function were normal. Since CMV retinitis is due to reactivation of latent CMV infection, it appears that selective loss of CMV-specific immunity had occurred, perhaps secondary to a thymoma. The causes of thymoma-associated immune impairment are not understood, but this case demonstrates that selective defects can occur in the absence of global T cell impairment. opportunistic infections should therefore be suspected in patients with thymoma even in the absence of quantitative immune deficiencies.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
4/35. Cancer-associated retinopathy associated with invasive thymoma.PURPOSE: To report a case of cancer-associated retinopathy associated with invasive thymoma. DESIGN: Interventional case report. METHOD: A 41-year-old Japanese woman was observed between February 1998 and May 2001. Ophthalmologic examinations and systemic examinations were performed. The patient received treatment including corticosteroid pulse therapy, plasmapheresis, and thymectomy. RESULTS: The patient developed progressive visual dysfunction including bilateral visual acuity loss, concentric contraction of visual fields, and color vision loss. In both eyes, retinal vessel attenuation and retinal pigment epithelium degeneration were observed with fundus ophthalmoscopy and fluorescein angiography. Response in electroretinogram was reduced, suggesting both rod and cone dysfunction. Autoantibody against 23-kD cancer-associated retinopathy (CAR) antigen (antirecoverin antibody) was detected in the patient's serum. A mediastinal tumor that was histopathologically diagnosed as invasive thymoma was detected and was surgically resected. During more than 3 years of follow-up, no other malignancy was detected despite extensive systemic evaluation. The patient also suffered from subclinical myasthenia gravis. Although temporary improvement of visual function was observed after treatment with steroid pulse therapy and plasmapheresis' light perception of each eye was lost in the end. CONCLUSIONS: The patient was diagnosed as having CAR. Invasive thymoma was considered to be the causative tumor because there had been no evidence that suggested other systemic malignancy during more than 3 years of follow-up.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/35. Microcytic variant of thymoma: histological and immunohistochemical findings in two cases.Two cases of microcytic variant of thymoma are presented. Both tumours were well encapsulated with a yellow-whitish colour and soft consistency. Microscopically, they consisted of round cells, having ample vacuolated cytoplasm. Fat droplets were not detected in one case where fat staining was performed. Immunohistochemically, the tumour cells were strongly positive for AE1/AE3, MB1, MB2, and LN1 and faintly positive for epithelial membrane antigen. They lacked any other leucocyte antigens. Leu 7 showed a positive immunoreaction in a ring-like or homogeneous pattern, compatible with the cytoplasmic vacuoles or cytoplasm. Ultrastructurally, the vacuoles resembled cystically dilated rough-surfaced endoplasmic reticulum. Desmosome-like structures (case 1) and intermediate junctions (case 2) were identified between adjacent cells. These findings indicate that the present tumours belong to a category of microcystic thymoma. The vacuoles were attributed to excess accumulation of Leu-7-positive material, probably in the cystically dilated endoplasmic reticulum.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
6/35. Thymic carcinosarcoma associated with a spindle cell thymoma: an immunohistochemical study.A case of thymic carcinosarcoma associated with a spindle cell thymoma in a 71-year-old woman is reported. Histological and immunohistochemical studies of the carcinosarcoma showed two quite different components: the sarcomatous component included cells with myoid differentiation which stained for desmin and muscle specific actin, and some isolated cells which stained positively for low molecular weight cytokeratin, while the carcinomatous component, which formed less than 10% of the tumour, showed an epithelial phenotype, being positive for low and high molecular weight cytokeratin and epithelial membrane antigen. The thymoma cells showed epithelial markers, and a few cells were also positive for desmin and muscle specific actin. The rarity of this tumour and its possible histogenesis are discussed.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/35. Ectopic cervical thymoma: a mimic of T-lymphoblastic lymphoma.Ectopic cervical thymoma is a rare tumor that probably arises from ectopic thymic tissue trapped during migration of thymic primordia in the embryonic stage. To the best of our knowledge, only 20 cases have been reported. Our patient was a 68-year-old woman who had been suffering from a nodular lesion in the anterior neck for several years. She underwent nearly total right thyroidectomy. Eight years and nine months after surgery, she is free of tumor recurrence or metastasis. The tumor was nodular with fibrous septa, and was composed of varying numbers of epithelial cells and lymphocytes, corresponding to AB thymoma as classified by WHO. Using lymphoid markers only, it was initially misdiagnosed as T-lymphoblastic lymphoma. The lymphocytes expressed T-cell antigens and terminal deoxynucleotidyl transferase and exhibited high proliferation fraction. awareness of ectopic cervical thymoma, careful microscopic examination, and a proper selection of antibodies for immunohistochemistry will lead to the correct diagnosis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/35. Successful treatment of Good syndrome with cytomegalovirus duodenoenteritis using a combination of ganciclovir and immunoglobulin with high anti-cytomegalovirus antibody titer.We describe the case of a 64-year-old woman with Good syndrome who presented with watery diarrhea and abdominal distention caused by cytomegalovirus (CMV) duodenoenteritis. thymoma and hypogammaglobulinemia were first identified when the patient was 58 years old. She had repeatedly complained of symptoms even after thymectomy. Abdominal radiography revealed multiple air-fluid levels, and computed tomography revealed ascites and dilation of the small intestine. Immunofluorescent staining of specimens obtained by duodenal mucosal biopsy revealed intracellular inclusion bodies of CMV, although serum CMV pp65 antigenemia assays yielded negative results. CMV infection of the small intestine caused mucosal edema resulting in malabsorption. The patient was treated using ganciclovir and an immunoglobulin preparation with a high titer of antibodies against CMV (CMV-Ig), and subsequently made a rapid recovery from abdominal symptoms. When patients with Good syndrome complain of abdominal symptoms, particularly chronic diarrhea, a diagnosis of CMV gastroenteritis should not be excluded, even if negative results are obtained for CMV pp65 antigenemia assays. Combination therapy of ganciclovir and CMV-Ig seems useful for patients with CMV gastroenteritis.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
9/35. Synchronous independent bifocal orthotopic thymomas. A case report.A case of synchronous multiple thymomas is reported. The patient was an 81-year-old woman with 2 separate thymomas in the anterior mediastinum. A histological study revealed that both thymomas consisted of dense lymphocyte infiltration in the stroma and a small number of polygonal epithelial tumor cells with clear nuclei and distinct nucleoli. Immunohistochemical staining using the antibodies to 2 antigens, bcl-2, and MIB-1 showed identical staining patterns. In spite of these findings, we considered their origin to be synchronous multicentric development rather than intra-thymic metastasis, based on the non-invasive nature of these tumors.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/35. thymoma arising within cardiac myxoma.Hematopoietic, glandular, and mesenchymal elements can be found within cardiac myxomas; ectopic endocrine tissues and "thymic rests" have also rarely been described. Atrial tumors (one right and one left) from 2 patients (a 69-year-old man and a 77-year-old woman) were encountered among the atrial myxoma cases in one of the author's consultation files. Both tumors were comprised of classic cardiac myxoma (with characteristic rings and syncytial chains of myxoma cells in a loose myxoid matrix) and cellular thymoma-like elements (characterized by a lobulated sheet-like growth of epithelioid spindle cells admixed with small lymphocytes punctuated by vessels with prominent perivascular spaces). Neither patient had evidence of thymoma elsewhere. Immunophenotypically, the thymoma-like component reacted strongly with antibodies to keratins (AE1/AE3, Cam 5.2, wide spectrum, CK19, CK7) and CD57 and weakly with antibodies to CD31, CD34, and calretinin. This intermediate phenotypic expression of both epithelial and vascular antigens likely reflects the multipotential nature of the cells comprising this lesion. The most likely explanation for this extremely unusual finding is neoplastic transformation of thymic rests within a myxoma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
| | Next -> |