1,721,011 research outputs found
Pediatric-type sarcomas in adult patients.
No full textSarcomas included in the broad group of small round-cell tumors (SRCT) and some non-SRCT lesions that typically are seen in pediatric-age patients can rarely occur in adults. However, there are differences in the anatomic sites that are involved and the prognosis in these two patient groups. The diagnosis of pediatric-type sarcomas in adults is often challenging because of the unusual contextual clinical setting and morphologic features. Immunohistochemical studies have greatly facilitated this process. Moreover, limited biomolecular studies that have been conducted have demonstrated comparable cytogenetic alterations in adults and children with pediatric-type tumors. They also have raised interesting questions concerning possible biological bases for differences in clinical behavior in the two cohorts. This review focuses on the morphological, immunohistochemical, and molecular characteristics of childhood-type sarcomas that affect adults, with emphasis on possible pitfalls in differential diagnosis
Small-cell carcinoma of gallbladder. An immunocytochemical and ultrastructural study.
No full textAn unusual carcinoma of the gallbladder in a seventy-one-year-old woman displayed features of a well-differentiated adenocarcinoma, atypical carcinoid and small cell undifferentiated carcinoma. The patient died from progressive hepatic failure four months after surgery. Autopsy showed bulky liver masses and several peritoneal nodules exclusively composed of small, hyperchromatic cells. The neuroendocrine nature of the small cell component of the tumor was documented by the presence of neurosecretory granules at the ultrastructural level and by immunocytochemical positivity to NSE and Synaptophysin. The epithelial markers, cytokeratin and CEA, were also positive in the carcinoid and in the undifferentiated portions of the tumor. A common endodermal origin is suggested for carcinoid and small cell carcinoma of the gallbladder
Primary carcinoid tumor of the cystic and common bile ducts.
No full textWe report a case of primary carcinoid tumor arising at the confluence of the cystic and common bile ducts. The patient was a 64-year-old woman who developed a sudden onset of biliary colic and jaundice. Computerized tomography and nuclear magnetic resonance showed a mass lesion close to the head of the pancreas. At laparotomy a nodular lesion was found at the confluence of the cystic and common bile ducts. Microscopic observation revealed a type B-C carcinoid (Soga's classification) with positive immunoreactivity to chromogranin and cytokeratin. The presence of neurosecretory intracytoplasmic granules was demonstrated by electron microscopy. Flow cytometry showed diploid DNA content of the neoplastic cells with less than 5% of the nuclei in the S-phase region
Polypoid angiomyofibroblastoma-like tumor of the oral cavity: a hitherto unreported soft tissue tumor mimicking embryonal rhabdomyosarcoma.
No full textWe report on a previously unrecognized fibro-myofibroblastic tumor in the oral cavity of a 15-year-old girl. Morphologically, the tumor mimicked a rhabdomyosarcoma, botryoid variant. It was composed of mitotically active small- to medium-sized, vimentin+/desmin+, round- to oval- to epithelioid-shaped cells embedded in an alternating fibrous to myxoid/edematous stroma. These cells were separated from the overlying squamous epithelium by a rim of fibrous stroma. The tumor contained abundant small- to medium-sized, thin-walled blood vessels without hyalinization. Frequently, neoplastic cells condensed around these vessels. An unusual and striking feature was the presence of numerous hyalinized collagen mats, including "amianthoid-like fibers", similar to those observed in myofibroblastomas. The presence of these collagen mats and the expression of desmin, in association with no immunoreactivity to myogenin and MyoD1, were in keeping with the fibro-myofibroblastic nature of the tumor, excluding the diagnosis of embryonal rhabdomyosarcoma. Regarding fibro-myofibroblastic tumors, we believe that the present case falls within the wide spectrum of benign stromal tumors, originally described in the lower female genital tract, but potentially occurring also at extragenital sites. As morphological and immunohistochemical features were reminiscent of, but not identical with, angiomyofibroblastoma, the term "polypoid angiomyofibroblastoma-like tumor" is proposed. Awareness and recognition of this tumor is crucial to avoid a diagnosis of malignancy
Undifferentiated sarcoma: does it exist? A clinicopathologic study of 7 pediatric cases and review of literature.
No full textUndifferentiated sarcomas are primitive mesenchymal tumors that cannot be classified among standardized histopathologic entities. Whether they represent a homogeneous group with common histogenesis and clinical behavior or comprise a variety of tumors able to differentiate along specific maturative lineages is still debated. To identify prognostic and histogenetic markers, we analyzed 7 undifferentiated sarcomas (4 in the trunk and 3 in the extremities). Mean patient age was 7.5 years, and mean follow-up was 18 months. Two clinicopathologic subtypes emerged from this study. Four primitive mesenchymal undifferentiated sarcomas arose mainly on the trunk and very proximal extremities, had an aggressive clinical course with poor outcome (3 deaths from disease, 1 with persistent disease), and displayed sheets of oval cells, with bland nuclei. Three spindle cell undifferentiated sarcomas arose on the extremities, had a favorable outcome, and showed elongated spindle cells with areas of primitive fibrosarcoma. All were negative for epithelial membrane antigen, cytokeratins, CD34, smooth muscle actin, desmin,Myf4, and HMB45 and showed nuclear staining for INI. Focal staining for S100 and CD99 was found in 3 and 4, respectively. Among stem cell markers, CD117 was positive in 3 cases (1 primitive, 2 spindle), nestin in 5 cases (4 primitive, 1 spindle), and CD105-stained tumor cells lining newly formed vascular spaces in 4 cases (1 primitive, 3 spindle). Survivin was weakly expressed in 6 cases and reflected low levels of mRNA (median survivin/GAPDH ratio, 1.096). Cytogenetic analysis revealed nonspecific translocations in 3 tumors. No translocations associated with Ewing sarcoma, synovial sarcoma, or alveolar rhabdomyosarcoma were found. In summary, primitive undifferentiated sarcomas occur in the trunk, behave aggressively, and express nestin. Spindle cell undifferentiated sarcomas occur in extremities, have a favorable outcome, resemble fibrosarcomas, and have similarly low survivin levels and display CD105-positive vascular spaces, which may represent an early hemangiopericytomatous patter
An unusual case of malignant pilocytic astrocytoma occurring in the eye.
No full textPilocytic astrocytoma is a central nervous system neoplasia that arises during pediatric age. Only few cases have been documented in patients older than 50 years old. It is a low-grade lesion that can rarely undergo malignant changes presenting the histologic features of a high-grade glioma. We report a case of a pilocytic astrocytoma arising in the eyeball of a 53-year-old man affected by glaucoma that underwent malignant evolutio
Histological evaluation of thyroid carcinomas: reproducibility of the "WHO" classification.
No full textAIMS AND BACKGROUND: Thyroid carcinomas display several pathologic features, show different behavior and necessitate different treatment; thus correct classification is mandatory.
METHODS: The kappa statistic was used as a measure of agreement in a panel of seven pathologists who reviewed 200 cases of thyroid tumors.
RESULTS: Overall agreement was 83% (k = 68). Good agreement was found for anaplastic (k = 0.85) and papillary carcinomas (k = 0.81); agreement for medullary carcinoma was acceptable (k = 0.80), suboptimal for other (k = 0.67), and poor for follicular carcinoma (k = 0.54).
CONCLUSIONS: Central pathology review of thyroid carcinomas is recommended when clinical and epidemiologic trials are planne
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