1/24. Intraabdominal desmoplastic small round cell tumor: report of a case with fine needle aspiration, cytologic diagnosis and molecular confirmation.BACKGROUND: desmoplastic small round cell tumor (DSRCT) is a recently described neoplasm. This entity is well defined, with distinct clinical, pathologic and immunohistochemical features. Molecular studies have shown a specific reciprocal translocation t(11;22)(p13;q12). To our knowledge, no report of DSRCT with molecular confirmation on cytologic material has been reported before. CASE: Fine needle aspiration (FNA) was performed on an intraabdominal mass in a 37-year-old man. A May-Grunwald-Giemsa-stained preparation showed clusters of small round tumor cells associated with desmoplastic stromal cells, highly suggestive of DSRCT. FNA of a supraclavicular node showed cytologic features similar to those of the primary abdominal mass, including a prominent desmoplastic reaction of the stroma. Immunocytochemical studies showed myogenic and epithelial differentiation. Molecular analysis was performed on FNA, revealing the EWS/ WT1 chimeric transcript and thus confirming the cytologic diagnosis. CONCLUSION: Cytomorphologically, a definitive diagnosis of DSRCT may be difficult, as this tumor bears considerable resemblance to other small round cell tumors. The diagnosis can be confirmed by ancillary techniques, such as immunocytochemistry, and particularly by molecular analysis, which may also be performed on cytologic material.- - - - - - - - - - ranking = 1keywords = stromal (Clic here for more details about this article) |
2/24. Endometrial stromal sarcoma: objective response to letrozole.BACKGROUND: Low-grade endometrial stromal sarcoma is generally an indolent tumor rich in estrogen and progesterone receptors. Objective responses to hormonal therapy, most commonly with megestrol acetate, have been reported. CASE: The patient is a 51-year-old woman who presented with low-grade endometrial stromal sarcoma confined to the uterus in 1991 and was treated with total abdominal hysterectomy and bilateral salpingo-oophorectomy. Approximately 5 years later, the patient had recurrent pelvic disease treated with radiation therapy, followed by an attempt at resection. She was treated with megestrol acetate during the period she received radiation therapy with poor tolerance. tamoxifen was then given with no tumor response. megestrol acetate was restarted with progression of disease in the pelvis and abdomen. Letrozole was then given at a daily dose of 2.5 mg with partial response for a duration of 9 months. CONCLUSION: Letrozole at a daily dose of 2.5 mg may be effective in low-grade endometrial stromal sarcoma with positive estrogen receptors.- - - - - - - - - - ranking = 7keywords = stromal (Clic here for more details about this article) |
3/24. An unusual case of complete Carney's triad in a 14-year-old boy.Carney's triad represents the association of gastric gastrointestinal stromal tumor, pulmonary chondroma, and extraadrenal paraganglioma. Only 79 cases of this rare condition have been described. Here, the authors describe the unusual case of a 14-year-old boy who presented with a complete Carney's triad. This is only the second reported case in the world literature of a patient manifesting a complete Carney's triad at presentation. The management of each tumor is discussed.- - - - - - - - - - ranking = 26.184060210409keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
4/24. Fine needle aspiration appearance of extragastrointestinal stromal tumor. A case report.BACKGROUND: gastrointestinal stromal tumors (GISTs) rarely develop outside the digestive tract and in the soft tissues of abdomen and retroperitoneum. Such tumors are designated extra-GISTs (EGISTs). Cytologic and immunocytochemical features of a case of EGIST are reported. CASE: A 54-year-old woman presented with a peritoneal mass, diameter 22 cm, adherent to the omentum and without a connection to the digestive tract. Fine needle aspiration biopsy (FNAB) of the excised tumor showed high cellularity in two patterns: monotonous spindle cells were intermingled with a mildly atypical epithelioid component. Immunocytochemistry performed on cytospins revealed reactivity for c-kit (CD117), CD34 and smooth muscle actin and negativity for S-100. The findings were concordant with a histologic diagnosis of EGIST. CONCLUSION: EGISTs are infrequent neoplasms and can be diagnosed in FNAB samples. The clinical/radiologic setting must be considered together with the cytologic features. Immunocytochemistry is a clue to the diagnosis when it detects c-kit reactivity.- - - - - - - - - - ranking = 105.73624084164keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
5/24. FDG PET imaging of metastatic gastrointestinal stromal tumor.A 75-year-old woman presented with an 8-month history of progressive abdominal distension and associated weight loss. Computed tomography (CT) showed a very large, partially enhancing, cystic/solid mass within the abdomen that extended from below the left diaphragm to the pelvis. A large (10 cm), partially enhancing lesion was also seen in segments 6 and 7 of the right lobe of the liver, consistent with metastatic disease. The patient underwent laparotomy and resection of a 5.7-kg abdominal tumor measuring 30 x 27 x 20 cm. histology confirmed a gastrointestinal stromal tumor (GIST) of stomach origin. A whole-body F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) scan performed 2 months postoperatively demonstrated multiple glucose-avid lesions in the liver as well as residual disease within the abdomen and pelvis. The patient was referred to medical oncology. The authors give a brief overview of this rare mesenchymal tumor of the gastrointestinal tract and the potential role of PET.- - - - - - - - - - ranking = 130.92030105205keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
6/24. Primary extrarenal Wilms' tumour: identification of a putative precursor lesion.We report a case of primary extrarenal Wilms' tumour which, on histological examination, revealed a zone of hyalinized blastema adjacent to, and within the tumour capsule. The tumour showed a predominant stromal component. The presence of the hyalinized blastema adjacent to the tumour raises the possibility that some cases of extrarenal Wilms' tumour may have a precursor lesion.- - - - - - - - - - ranking = 1keywords = stromal (Clic here for more details about this article) |
7/24. cytodiagnosis and comparison of nondecidualized and decidualized endometriosis of the abdominal wall. A report of two cases.We describe two cases of endometriosis of the abdominal wall occurring in young, multiparous women in which the diagnosis was made by fine needle aspiration biopsy. One case illustrates the cytologic features of non-decidualized endometriosis: a biphasic population of stromal and glandular cells. In contrast, the other case showed large, plump stromal cells in a distinctive myxoid background, creating a picture of decidualized endometriosis. The differential diagnoses of palpable masses in the abdominal wall and the importance of clinicopathologic correlation are discussed.- - - - - - - - - - ranking = 2keywords = stromal (Clic here for more details about this article) |
8/24. A new mutation in the KIT ATP pocket causes acquired resistance to imatinib in a gastrointestinal stromal tumor patient.BACKGROUND & AIMS: Imatinib, a tyrosine kinase inhibitor of BCR-ABL, KIT, and platelet-derived growth factor receptor, is used in patients with chronic myelogenous leukemia (CML) and gastrointestinal stromal tumors (GIST). Primary and acquired resistance to the drug can occur in both diseases. Molecular mechanisms have been reported in CML and GIST for primary resistance, whereas extensive studies on the mechanisms responsible for secondary resistance have been almost exclusively reported for CML. methods: In a patient with advanced GIST undergoing imatinib therapy, an isolated progressing peritoneal mass was excised, along with 2 still-responding lesions. Complementary dna and genomic dna were analyzed by sequencing for c-Kit gene mutations. KIT receptor expression and phosphorylation status were assessed by immunoprecipitation and Western blot. Transient-transfection experiments were performed with mutagenized KIT constructs, and their activation status was assessed. RESULTS: In addition to an exon 11 mutation, shared among all of the analyzed lesions, a novel point mutation in c-Kit exon 14 resulting in T670I substitution was found only in the progressing lesion, which harbored a phosphorylated receptor, as opposed to the finding of an inactive receptor in responding lesions. Functional analyses showed that KIT/T670I is insensitive to imatinib and that T670I mutation, introduced in a receptor responding to imatinib, subverted its sensitivity to the drug. CONCLUSIONS: This new mutation was confined to the progressing lesion; the resulting amino acidic substitution, T670I, affecting the ATP/imatinib pocket of KIT, makes it insensitive to the drug. Interestingly, this substitution is a homologue to the T315I mutation already reported in CML, where it is responsible for acquired resistance to imatinib.- - - - - - - - - - ranking = 130.92030105205keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
9/24. Digestive PEComas: a solution when the diagnosis fails to "fit".We report two cases of digestive/intra-abdominal PEComa. The first lesion developed in the caecum of a 36-year-old woman, the second in the pararectal region of a 35-year-old woman. The first tumor was formed from spindle cells arranged in fascicles, the second contained predominantly epithelioid cells with prominent nucleoli. Immunohistochemically, tumor cells expressed smooth muscle actin and melanocyte markers (HMB45), S-100 protein and CD117 were negative. Based on the morphologic aspect and, above all, on the immunohistochemical study the diagnosis of PEComa was retained for both lesions. In the gastrointestinal tract, the principal differential diagnoses of PEComas are gastrointestinal stromal tumors, particularly the round cell/epithelioid subtype, and metastases of carcinoma and melanoma. Other differential diagnoses include rhabdomyosarcoma, paraganglioma, leiomyosarcoma, and clear cell sarcoma.- - - - - - - - - - ranking = 26.184060210409keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
10/24. Clinicopathological and immunohistochemical features of extragastrointestinal stromal tumors: report of two cases.CD117 (c-kit proto-oncogene protein product) is expressed in most gastrointestinal stromal tumors (GISTs) and plays a crucial role in the pathogenesis and treatment of this disease. However, the clinicopathological and immunohistochemical features of CD117-positive mesenchymal tumors without connection to the gastrointestinal tract, known as extragastrointestinal stromal tumors (EGISTs), are not well documented because these tumors are rare. We describe the clinicopathological and immunohistochemical features of two cases of EGIST and compare them with those of GIST. Of the 1855 abdominal or esophageal tumors resected during the past 10 years at our hospital, 23 were GISTs and 2 were EGISTs. The clinicopathological or immunohistochemical characteristics do not seem to differ remarkably between EGISTs and GISTs. Although rare, CD117 positivity should be tested in abdominal mesenchymal tumors that have no connection to the gastrointestinal tract. The clinicopathological features of CD117-positive abdominal mesenchymal tumors may not depend on whether the tumor is connected to the gastrointestinal tract.- - - - - - - - - - ranking = 157.10436126245keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
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