1/48. Malignant rhabdoid tumor of the colon: report of a case.A malignant rhabdoid tumor of the colon is very rare and only three cases have been previously described. A 76-year-old man was admitted to the hospital complaining of epigastralgia. An elastic mass was palpable in the right upper abdomen. A barium enema and endoscopic examination showed a giant gyrate tumor arising from the cecum. Abdominal ultrasonography and a computed tomography scan revealed the tumor to be located in the colon associated with multiple liver metastases and gallbladder stones. A right colectomy and cholecystectomy were thus performed. The tumor was histologically composed of sheets of large round and polygonal nuclei with vesicular chromatin, and abundant acidophilic cytoplasm, often containing hyalin-like inclusion. The cytoplasm was positive for vimentin and neuron-specific enolase, and hyaline globules of the rhabdoid tumor cells stained positive for cytokeratin in some cells. Transmission electron microscopy showed characteristic rhabdoid cells with an aggregation of intermediate filaments. A histologic diagnosis of malignant rhabdoid tumor of the colon was made. The tumor demonstrated several unusual findings for malignant rhabdoid tumors including diploidy by a flow cytometric analysis, and positive nuclear immunohistochemical staining for p53 protein and ki-67 antigen. We report herein the third known case of a pure colonic rhabdoid tumor.- - - - - - - - - - ranking = 1keywords = intermediate (Clic here for more details about this article) |
2/48. Follicular thyroid carcinoma with rhabdoid phenotype.The aim of this paper is to highlight the occurrence of an unusual histological variant of follicular carcinoma of the thyroid. Three cases are presented: each of the tumours contained a significant population of rhabdoid cells (accounting for 30-40% of the total tumour content). They were all found in female patients aged 65, 43 and 56 years, who presented with enlarged thyroid glands and were subjected to lobectomies. The tumours contained foci of well-differentiated follicular carcinoma, with areas of capsular and vascular invasion, and an accompanying rhabdoid cell component that merged with the neoplastic follicles. Immunohistochemically, the follicular component was positive with thyroglobulin, but the rhabdoid cells were negative in all three cases. The cytoplasmic aggregates in the rhabdoid cells were strongly positive for epithelial markers and vimentin. Two tumours pursued an aggressive biological course similar to other composite extrarenal rhabdoid tumours. A rhabdoid component accompanying thyroid follicular carcinomas is an adverse prognostic factor.- - - - - - - - - - ranking = 0.00062453672248179keywords = lobe (Clic here for more details about this article) |
3/48. Primary malignant rhabdoid tumours of brain, clinicoradiological findings of two cases.Malignant rhabdoid tumours (MRT) are extremely malignant, highly aggressive and uncommon renal neoplasms of childhood with very poor prognosis. About fifteen cases of primary intracranial MRT (with their clinical details) are reported in English literature, following the recognition of this entity in 1978. Two cases of MRT are reported here. The first case, one year male baby was admitted with a very large, infiltrative, posterior fossa mass. He required elective ventilation, following the tumour decompression but ultimately died of respiratory failure during the process of weaning from the ventilator. The second child was operated for an extremely vascular, very friable, solid and lobulated tumour of temporal lobe. Radical microsurgical decompression of mass was achieved, however the child developed massive recurrence, documented five weeks after the surgery while on radiotherapy. His recurrence showed partial response to radiotherapy and chemotherapy. The child is alive at 8 month's follow up, but probably passing the terminal days of his life. Hence the recognition of this entity is very essential for the aggressive management and prognostication of the patient, which obviously seems to be different from primitive neuroectodermal tumour.- - - - - - - - - - ranking = 0.00062453672248179keywords = lobe (Clic here for more details about this article) |
4/48. Pineal malignant rhabdoid tumor with chondroid formation in an adult.A pineal tumour in a 27-year-old male is presented with the characteristic histological features of a pineal malignant rhabdoid tumor (MRT) with chondroid formation. Occasionally, tumor cells contained a single well-demarcated hyaline globular inclusion within the cytoplasm adjacent to the nucleus. The stroma of these tumors tends to be densely hyalinized and become chondroid. Immunohistochemical staining was positive for vimentin, epithelial membrane antigen, chromogranin a, synaptophysin, neuron-specific enolase, S-100 protein, and muscle actin. Despite surgery and radiochemotherapy, the tumor recurred in the pineal region and metastasized to the lower lobe of right lung. The patient died 2 years after the initial diagnosis. This is the second published case of central nervous system-MRT appearing in an adult. The clinical and pathological features of pineal MRT in this patient are presented.- - - - - - - - - - ranking = 0.00062453672248179keywords = lobe (Clic here for more details about this article) |
5/48. Endometrial stromal sarcoma of the uterus with rhabdoid features.A case of endometrial stromal sarcoma of the uterus with rhabdoid features, occurring in a 57 year old woman is reported. Electron microscopy and immunohistochemistry revealed that the rhabdoid cells contained intermediate filaments which were positive for vimentin, cytokeratin, alpha-smooth muscle actin, and muscle specific actin, but not for myoglobin and desmin. This indicated that the tumor in this case differed somewhat from the three rhabdoid tumors and an endometrial stromal sarcoma with rhabdoid differentiation previously reported and that, therefore, these tumors were heterogeneous.- - - - - - - - - - ranking = 1keywords = intermediate (Clic here for more details about this article) |
6/48. carcinosarcoma with rhabdoid features of the urinary bladder in a 2-year-old girl: possible histogenesis of stem cell origin.A case of carcinosarcoma of the urinary bladder in a 2-year-old girl is reported. The tumor, measuring 34 x 20 x 18 mm, was located in the peri-trigone area of the urinary bladder with polypoid features. Histologic examination revealed transitional cell carcinoma at the tumor surface with downward invasion. Concurrently, a sarcomatous area was found beneath the carcinoma, with these two different malignant components sharing on apparent transition without distinct boundaries. Sarcomatous components included immature round cells focally showing rhabdoid features. No rhabdomyomatous component was observed. immunohistochemistry disclosed vimentin and cytokeratin-double positive cells at the transposition between carcinoma and sarcomatous components. In addition, ultrastructural analysis revealed that the epithelial cells had a distinct junctional complex, and the sarcomatous cells occasionally had a meshwork of cytoplasmic intermediate filaments, indicating bidirectional cytodifferentiation to epithelial and mesenchymal elements. The extremely young age at which this case of carcinosarcoma occurred suggests that the tumor may be of mesodermal stem cell origin.- - - - - - - - - - ranking = 1keywords = intermediate (Clic here for more details about this article) |
7/48. Poorly differentiated follicular thyroid carcinoma with rhabdoid phenotype: a clinicopathologic, immunohistochemical and electron microscopic study of two cases.Poorly differentiated thyroid carcinomas with follicular cell phenotype are not well defined. Different diagnostic criteria have been employed for these tumors, including solid growth, nodular, trabecular, and insular patterns. Cytologic features, such as a predominance of tall and columnar cells, have been considered to be diagnostic of poorly differentiated carcinoma. However, there is no agreement among surgical pathologists regarding morphologic criteria for poorly differentiated thyroid carcinoma. We report two unique thyroid neoplasms that we interpreted as poorly differentiated follicular carcinomas. Nodular, trabecular, and sheetlike patterns predominated in both tumors. They were composed of cells that were focally immunoreactive for thyroglobulin and had large vesicular nuclei with prominent nucleoli. A variable number of cells showed rhabdoid phenotype. The rhabdoid inclusions did not stain for thyroglobulin but contained whorls of intermediate filaments that were vimentin positive. There were foci of necrosis and numerous mitotic figures. Both patients were adults and died with multiple pulmonary metastases. The presence of rhabdoid cells in poorly differentiated follicular carcinomas broadens the spectrum of tumors with rhabdoid phenotype. More cases are needed to determine whether the rhabdoid phenotype is a marker for poorly differentiated follicular carcinoma as well as an independent adverse prognostic factor.- - - - - - - - - - ranking = 1keywords = intermediate (Clic here for more details about this article) |
8/48. Classical malignant rhabdoid tumor of central nervous system in 9-year-old Korean.A Malignant rhabdoid tumor (MRT) arising in the right temporoparietal lobe of a 9-year-old boy is described along with the results of an immunohistochemical study. The patient initially sought medical attention for a ptosis and right sided headache. The child underwent a subtotal resection of the tumor, followed by radiotherapy and systemic chemotherapy, but died three years after surgery. A MRT, a primary neoplasm of the central nervous system (CNS), is an entity of unknown histogenesis with a dismal prognosis, which only occurs in early childhood. Histologically similar tumors with more varied morphological features have been designated as an atypical teratoid/rhabdoid tumor. However, a classical MRT is extremely rare in the CNS and our case represents a classical CNS MRT.- - - - - - - - - - ranking = 0.00062453672248179keywords = lobe (Clic here for more details about this article) |
9/48. Mutations of the p53 gene in malignant rhabdoid tumors of soft tissue and the kidney: immunohistochemical and dna direct sequencing analysis.Malignant rhabdoid tumor (MRT) is characterized by the presence of intracytoplasmic eosinophilic inclusions composed of whorls of intermediate filaments. This tumor was originally described as an entity of the abortive type of Wilms' tumor in childhood. Recently, it has been proved that these rhabdoid cells can be observed in various types of malignant tumors, including soft tissue sarcoma or carcinoma. To investigate the oncogenesis of this tumor, we examined the p53 gene alteration by means of immunohistochemical analysis and dna direct sequencing in three cases of malignant rhabdoid tumor (MRT) of the soft tissue and three cases of MRT of the kidney. All the cases of MRT of the soft tissue and two of the cases of MRT of the kidney showed immunopositivity for p53 protein. Among them, one of the cases of MRT of the soft tissue and two of the cases of MRT of the kidney showed missense mutations of the p53 gene. These results strongly suggest that p53 gene alterations may have an important role to play in the aggressive biological behavior and poor prognosis of this tumor.- - - - - - - - - - ranking = 1keywords = intermediate (Clic here for more details about this article) |
10/48. Rhabdoid papillary meningioma.We have studied an uncommon case of rhabdoid papillary meningioma in a 15-year-old boy with a dura-based mass arising in the left posterior fossa. The patient exhibited prominent extracranial extension during the past 6 years, consisting of a mixture of both perivascular pseudopapillary growth and rhabdoid cytologic features of neoplastic meningothelial cells. The meningothelial features were evidenced by the focal whorl formation of tumor cells, coexpression of epithelial membrane antigen and vimentin, and ultrastructural findings of interdigitated cytoplasmic process and intercellular junction. However, the regional and histologic resemblances to ependymoma were further complicated by unexpected focal expression of glial fibrillary acidic protein, neurofilament, and alpha-smooth muscle actin of the tumor cells. The rhabdoid morphology was characterized by sheets of tumor cells with eccentric nuclei and abundant eosinophilic cytoplasm with often recognizable intracytoplasmic hyaline inclusions. These inclusions revealed ultrastructural paranuclear whorls of intermediate filaments, ruling out the other forms of intracytoplasmic eosinophilic inclusions resembling rhabdoid morphology. diagnosis of an unusual rhabdoid papillary meningioma with aggressive behavior is resoluble by immunohistochemical and ultrastructural analyses.- - - - - - - - - - ranking = 1keywords = intermediate (Clic here for more details about this article) |
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