1/99. Signet ring epithelioid stromal tumor of the small intestine.Cells having a signet ring appearance can occur in mesenchymal, lymphoid, and other nonepithelial neoplasms. We report the case of an intestinal stromal tumor with smooth muscle differentiation and a prominent signet ring cell component. The presence of signet ring forms of smooth muscle cells in sections of paraffin-embedded tissue often contrasts with a lack of cytoplasmic spaces by electron microscopy, and the ultrastructural finding of signet ring-like areas in the present case can be attributed to the fact that the tissue for electron microscopy was retrieved from paraffin blocks where this peculiar artifact already existed. Ultrastructural examination of the signet ring-like areas suggests that they originated as retraction spaces which may have resulted from variations in intracellular tension forces related to the distribution of actin filaments.- - - - - - - - - - ranking = 1keywords = stromal (Clic here for more details about this article) |
2/99. Renal angiomyolipoma resembling gastrointestinal stromal tumor with skenoid fibers.We report an unusual case of renal angiomyolipoma occurring in 68-year-old man. The tumor lacked well-developed vascular and adipose components and was composed almost exclusively of smooth muscle cells. Numerous skenoid-like periodic acid-Schiff-positive globules were interspersed between the tumor cells; the lesion therefore closely resembled a low-grade stromal tumor of the gastrointestinal tract. The HMB45-positive/CD34-negative immunophenotype was essential for the diagnosis of angiomyolipoma. Neither gastrointestinal tumor nor any signs of tuberous sclerosis were found. This lesion should be included in the list of morphologic variations of angiomyolipoma, which may cause diagnostic difficulties.- - - - - - - - - - ranking = 137.9503238813keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
3/99. High mitotic index associated with poor prognosis in gastrointestinal autonomic nerve tumour.AIMS: Three gastrointestinal autonomic nerve tumours (GANT) were characterized by immunohistochemistry and flow cytometry. Two of the three cases occurred in the small intestine, while the third was found in the stomach. Besides the immunohistochemical and ultrastructural description, the aim of this study was to examine the relation between the known and accepted predictive factors (ploidy data, the S-phase fraction, the mitotic and MIB-1 index and the size of the tumour) and the survival of the patients. methods AND RESULTS: The immune profile showed that 3/3 cases were vimentin and NSE, 2/3 were synaptophysin and PGP 9.5 positive, while 1/3 also showed S100 positivity. Ultrastructurally, all the cases had dense core granules, one of them contained skenoid fibres. The flow cytometry revealed diploid dna in all cases, however, significant differences could be seen in the proliferative activity of the individual neoplasms. CONCLUSIONS: In spite of the published data of gastrointestinal stromal tumours (GIST) generally, neither the MIB-1 index and the ploidy data nor the size of the primary tumour helped to predict the clinical progression of the examined GANTs. However, the high proliferative activity (57 mitoses/10 HPF) and the elevated S-phase fraction (24%) was associated with advanced, metastatic and recurring disease in case 3. On the basis of these three cases, high mitotic activity is the most reliable factor in predicting aggressive clinical behaviour.- - - - - - - - - - ranking = 94.571042803375keywords = gastrointestinal stromal tumour, gastrointestinal stromal, stromal tumour, stromal (Clic here for more details about this article) |
4/99. A new observation of the Carney's triad with long follow-Up period and additional tumors.The etiology of the Carney's triad (gastrointestinal stromal tumors, pulmonary chondromas, and paragangliomas) is unknown, and only 57 cases have been reported since its identification in 1977. We report the clinical course of a female with the complete triad and some additional tumors. Bilateral vagal paragangliomas were treated surgically and with radiotherapy between the ages of 24 and 26 years. Subsequently she underwent surgery for a gastric leiomyosarcoma (27 years), a pleomorphic adenoma of the parotid gland (49 years) and a multifocal breast cancer with axillary spread (50 years). A calcified lesion was also noticed in the left lung, the radiologic diagnosis of which was consistent with chondroma. A mediastinal paraganglioma, detected at 56 years on a control X-ray of the chest, was partially excised at 63 years. At the last control, performed at 66 years, the patient was alive with residual cervical and mediastinal paraganglioma. Her younger brother was affected by Hirschsprung's disease and died at 54 years of rectal cancer. Her daughter is 33 and has been suffering since birth with severe constipation. In conclusion, this is one of the longest followed-up patients with Carney's triad. Her case illustrates the need for early recognition of the setting in order to detect the component tumors at a stage when surgery may be curative, and careful and life-long follow-up, both because the multicentricity of the classic components tends to manifest metachronously and because of the tendency to develop other tumors, some of which may be malignant. Furthermore, the presence of Hirschsprung's disease in the patient's family, coupled with the alleged common origin of two component lesions from derivatives of the neural crest, open new avenues for the understanding of this disorder.- - - - - - - - - - ranking = 34.437580970326keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
5/99. GANT-like gastrointestinal pacemaker cell tumours with oncocytic features.We describe two cases of gastrointestinal stromal tumours with prominent oncocytic features. Both had features consistent with differentiation towards the interstitial cells of cajal (CC). They were composed of nests and bundles of cells with abundant, deeply granular, eosinophilic cytoplasm. Immunohistochemical investigations revealed positivity with c-kit, vimentin and CD34 antibodies in both neoplasms. Ultrastructurally the neoplastic cells showed characteristic features of CC; they had synapse-like structures and dense core cytoplasmic granules. Oncocytic features were confirmed by immunohistochemistry using anti-mitochondrion antibody in both cases and by electron microscopy in one case (case 1). Although the CC are frequently described as mitochondrion-rich cells, oncocytic changes have not previously been reported as a feature of gastrointestinal autonomic nerve tumour (GANT)-like stromal tumours.- - - - - - - - - - ranking = 99.996297299386keywords = gastrointestinal stromal tumour, gastrointestinal stromal, stromal tumour, stromal (Clic here for more details about this article) |
6/99. gastrointestinal stromal tumors treated by laparoscopic surgery: report of three cases.Three cases of gastrointestinal stromal tumors (GIST) were treated by a laparoscopic wedge resection of the stomach. The tumor characteristics were confirmed to be nonepithelial, nonlymphomatous, nonmyogenic, and nonneurogenic gastrointestinal neoplasms with an uncertain origin which were CD34-positive and actin- and S-100-negative. The malignant potential was estimated based on the mitotic figures and growth rates. The results suggest that laparoscopic surgery is an adequate strategy for gastric submucosal tumors including GIST, and also indicates this technique to be a curative, safe, and minimally invasive procedure for both diagnosis and treatment.- - - - - - - - - - ranking = 35.237580970326keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
7/99. Spindle cell tumor of urinary bladder serosa with phenotypic and genotypic features of gastrointestinal stromal tumor.Most mesenchymal tumors of the gastrointestinal tract are now referred to as gastrointestinal stromal tumors (GISTs). The tumors differ from ordinary leiomyomas and schwannomas in several respects: the GISTs typically express c-kit protein (CD117) and CD34, 30% to 50% of them are (often focally) positive for alpha-smooth muscle actin, and all are negative for desmin and S100 protein. Recently, mutations in the exon 11 of the c-kit gene have been identified and confirmed as a molecular genetic marker for the subset of GISTs. In this report, we describe a mesenchymal tumor removed from the pelvic cavity of a 52-year-old woman, who is alive without disease 36 months after the surgery. The 5-cm tumor was densely attached to the external aspect of the urinary bladder but was attached to small intestine by only filmy adhesions. The tumor grossly resembled a leiomyoma and was histologically composed of sheets of spindle cells with a dense collagenous background. The mitotic activity was low, less then 1 per 50 high-power fields. Immunohistochemically, the tumor cells were negative for alpha-smooth muscle actin and desmin and positive for CD117 and CD34. Molecular genetic analysis of the exon 11 of the c-kit gene revealed a point mutation in the region commonly mutated in GISTs. This mutation substituted T for A in the codon 557, leading to the change of amino acid sequence (tryptophan for arginine) of the KIT protein. This case illustrates that tumors phenotypically and genotypically similar to GISTs may present in sites other than the tubular gastrointestinal tract.- - - - - - - - - - ranking = 172.18790485163keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
8/99. c-kit immunocytochemical staining in the cytologic diagnosis of metastatic gastrointestinal stromal tumor. A report of two cases.BACKGROUND: Gastrointestinal stromal tumor (GIST) is a distinct group of mesenchymal neoplasms recently shown to exhibit differentiation toward interstitial cells of cajal (ICC). C-kit (CD117), an immunocytochemical marker consistently expressed in normal ICC, is demonstrable in 81-100% of GISTs. We report two cases wherein immunocytochemical staining for c-kit aided in the diagnosis of metastatic GIST in the liver. CASES: Two patients, a 37-year-old female (case 1) and a 76-year-old male (case 2), presented with multiple nodules in the liver. They had a history of small bowel GIST resected 11 and 1 year earlier, respectively. Fine needle aspiration of the liver nodules showed loose aggregates or fascicles of spindle cells with elongated to oval nuclei, rare paranuclear vacuoles and eosinophilic cytoplasm. The spindle cells showed minimal (case 1) to moderate nuclear pleomorphism (case 2), with occasional mitotic figures seen in case 2. Immunocytochemical staining revealed strong and diffuse staining for c-kit; it was negative for actin, desmin, CD34 and S-100 protein. Thus, a diagnosis of metastatic GIST was rendered. Histologic review of the primary small bowel GISTs of both cases and the subsequently resected liver nodules in case 1 confirmed the diagnosis. CONCLUSION: Metastatic GIST may pose diagnostic problems due to its broad morphologic spectrum and variable cytologic atypia; in particular, distinction from leiomyosarcoma and other mesenchymal tumors is difficult. The diagnostic difficulty is compounded when the prior history of gastrointestinal tumor is not available or forgotten and when GIST is the initial presentation of the tumor. C-kit is a highly sensitive and reliable immunocytochemical marker that can aid in the diagnosis.- - - - - - - - - - ranking = 137.9503238813keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
9/99. Duodenal carcinoid tumor: report of a case diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy with immunocytochemical correlation.Fine-needle aspiration biopsy is a reliable and accurate method for the endoscopic diagnosis of gastrointestinal malignancies and it is particularly well suited for evaluation of submucosal lesions. We report the cytopathologic findings of a case of malignant carcinoid tumor of a 44-year-old male who presented with melena and a nonhealing duodenal ulcer. Endoscopic ultrasound examination revealed a submucosal lesion in the pyloric region. Fine-needle aspiration revealed abundant cellularity with tumor cells arranged in sheets and loose groups and dispersed single cells in a clean background. Papillary fragments, capillaries cuffed by tumor cells, and rosette formation were also noted. The cells were moderate in size, round to oval, with a small subpopulation of spindle-shaped cells. The nuclei were uniform, round to oval, with smooth nuclear borders. The chromatin pattern was finely granular with a salt-and-pepper appearance. The cytoplasm of the cells was small to moderate in amount, pale, and showed fine granularity. The differential diagnosis included a neuroendocrine neoplasm vs. an epithelioid gastrointestinal stromal tumor. The tumor cells were focally positive for chromogranin and negative for CD34, supporting the diagnosis of a neuroendocrine neoplasm. The differential diagnosis of primary gastrointestinal carcinoid tumors from gastrointestinal stromal tumors can be very difficult in cytologic material. In cases when diagnostic material is scant, or only present on one smear, the use of smear division and cell transfer in order to perform immunocytochemical stains may be of considerable value to confirm the neuroendocrine nature of the neoplasms.- - - - - - - - - - ranking = 68.875161940651keywords = gastrointestinal stromal, stromal (Clic here for more details about this article) |
10/99. Gastrointestinal stromal tumor with skeinoid fibers of the ileum.Gastrointestinal stromal tumor (GIST) is not uncommon among gastrointestinal nonepithelial tumors, but there are few reports describing the cytologic findings. We report a case of GIST with skeinoid fibers in scrape cytology preparation. The patient was a 53-year-old man with a tumor in the small intestine. Scrape preparations from the cut surface of the resected tumor revealed cellular material composed of spindle cells showing loose clusters or single cells. The nuclei were spindled, elongated or cigar-shaped, and relatively uniform. The cytoplasm was fragile and demonstrated a finely fibrillar material. Dense hyaline materials with irregular outline were observed within the loose clusters composed of the tumor cells. The hyaline materials were also observed in the background. Histologic preparation showed spindle cells arranged in a fascicular or storiform pattern. Most eosinophilic globules were distributed between the tumor cells. The globules were positive in periodic acid-schiff reaction, and were stained blue with Masson's trichrome stain. Immunohistochemically, the tumor cells were strongly and diffusely positive for c-kit, focally and weakly positive for alpha-smooth muscle actin, and negative for CD34 and S-100 protein. We emphasize that skeinoid fibers are characteristic of GIST arising in the small intestine, and their presence predicts a good prognosis, even in malignant GIST.- - - - - - - - - - ranking = 1keywords = stromal (Clic here for more details about this article) |
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