1/33. 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 = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
2/33. 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 = 2keywords = spindle cell, spindle (Clic here for more details about this article) |
3/33. 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 = 0.26259683880689keywords = spindle (Clic here for more details about this article) |
4/33. 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 = 2.2625968388069keywords = spindle cell, spindle (Clic here for more details about this article) |
5/33. Congenital gastrointestinal stromal tumour is morphologically indistinguishable from the adult form, but does not express CD117 and carries a favourable prognosis.AIMS: The histological and immunohistochemical features of a congenital stromal tumour of the jejunum are compared with those of adult gastrointestinal stromal tumours (GIST). The literature concerning the diagnosis and prognosis of congenital small intestinal stromal tumours is reviewed. methods AND RESULTS: A term female infant presented with intestinal obstruction, from birth. histology of a 15-mm jejunal nodule showed a predominantly spindle-cell tumour with epithelioid areas. There was a low mitotic count and mild nuclear pleomorphism, extensive necrosis and haemorrhage, and focal calcification. Immunohistochemically, tumour cells stained for muscle specific actin and vimentin. Staining for CD117 (c-kit), S100, desmin and CD34 was negative. The features were compared to those of seven adult cases: no morphological feature was specific to the congenital tumour, which was smaller than the adult cases. There were no ultrastructural features specific for a particular line of differentiation. Immunohistochemical staining patterns were similar, except for CD117, which was strongly positive in all adult tumours, but negative in the congenital tumour. CONCLUSIONS: This congenital jejunal stromal tumour morphologically resembled adult GIST, but lack of c-kit expression suggests that it is nosologically distinct. Despite the presence of histological features which would cause the tumour to be categorized as malignant in an adult, it is apparent from previous reports of congenital small intestinal stromal tumours that the prognosis is favourable.- - - - - - - - - - ranking = 0.26259683880689keywords = spindle (Clic here for more details about this article) |
6/33. Malignant gastrointestinal stromal tumor showing remarkable whorl formations.A case of malignant gastrointestinal stromal tumor (GIST) is reported. Histologically, spindle cell proliferation with remarkable whorl formations was predominant in the tumor. Immunohistochemically, the tumor cells were diffusely positive for CD117 (c-Kit) and vimentin and partially positive for CD34. Ultrastructurally, the desmosome-like structures and interdigitations occurred much more frequently in the areas with whorl formations. These organelles were considered to be closely associated with the whorl formations. Various kinds of cellular arrangements are revealed in GISTs, but remarkable whorl formations, such as in our case, are a rare variant pattern. Herein, we discuss the histopathologic differences between this and other tumors showing whorl formations and describe the meaning of this unique arrangement. GISTs are thought to be immature tumors, and, therefore, variations in histopathologic findings are recognized. Finally, the ultrastructural study of GISTs is useful for understanding the mechanisms forming whorl formations and the differentiation or pathogenesis of GISTs.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
7/33. Gastrointestinal stromal tumor of the lesser omentum: report of a case.We describe herein an extremely unusual case of a gastrointestinal stromal tumor (GIST) of the lesser omentum. A 45-year-old man was admitted to our hospital with an intra-abdominal mass that was subsequently misdiagnosed as a submucosal tumor of the stomach. The tumor arose from the lesser omentum and was removed without difficulty. Histologically, the tumor was composed of spindle-shaped cells with an interlacing bundle pattern, and immunohistochemical examination showed that it was positive for myeloid stem cell antigen (CD34), but negative for HHF35 and S-100 protein. These findings were consistent with a GIST lacking myogenic features and neural attributes. The patient had an uneventful postoperative course, and was free of recurrence when last seen 11 months after his operation.- - - - - - - - - - ranking = 0.26259683880689keywords = spindle (Clic here for more details about this article) |
8/33. Gastrointestinal stromal tumor of the duodenal ampulla: report of a case.We report herein the case of a 77-year-old woman with a gastrointestinal stromal tumor (GIST) of the duodenal ampulla. The tumor, which was removed by pancreatoduodenectomy due to its malignant potential, showed expansive growth in the muscular coat of the duodenal ampulla. Histologically, the tumor cells were spindle-shaped or round, and exhibited fascicular or storiform growth pattern with frequent mitotic figures. The immunohistochemical and ultrastructural results suggested that the tumor may have originated from the interstitial cells of Cajal in the muscular coat of the duodenal ampulla. To our knowledge, this is the first case of malignant GIST of the duodenal ampulla to be reported in japan.- - - - - - - - - - ranking = 0.26259683880689keywords = spindle (Clic here for more details about this article) |
9/33. Familial multiple gastrointestinal stromal tumours with associated abnormalities of the myenteric plexus layer and skeinoid fibres.AIMS: Multiple familial gastrointestinal stromal tumours are rare. We report the third family with two cases of multiple gastrointestinal stromal tumours showing skeinoid fibres. Associated abnormalities of the myenteric plexus layer are described and new hypotheses for the histogenesis of gastrointestinal stromal tumours are formulated. methods AND RESULTS: Multiple gastrointestinal stromal tumours developed in the duodenum and proximal jejunum were removed from mother and son. No history of a specific syndrome or of mastocytosis was known. light microscopy revealed typical gastrointestinal stromal tumours with skeinoid fibres. An unusual abnormality of the myenteric plexus layer, showing a diffuse spindle cell hyperplasia, was noted in the macroscopically normal digestive wall. No abnormalities of the ganglion cells were associated. Tumours and the spindle cell hyperplasia showed similar morphological and immunohistochemical features with expression of CD34 and CD117 antigens. Follow-up revealed recurrences in the mother. CONCLUSION: The morphological characteristics of these two cases of familial gastrointestinal stromal tumours and of the associated abnormalities of the myenteric plexus layer, help to better explain the histogenesis of multiple familial gastrointestinal stromal tumours. The hyperplasia of the myenteric plexus could be considered a risk factor for recurrent tumours.- - - - - - - - - - ranking = 2keywords = spindle cell, spindle (Clic here for more details about this article) |
10/33. gastrointestinal stromal tumors in the appendix: a clinicopathologic and immunohistochemical study of four cases.Mesenchymal tumors of the appendix are very rare, and specific stromal tumors (i.e., gastrointestinal stromal tumors, GISTs) have not been reported in this location to date. Four GISTs were identified in the review of primary mesenchymal tumors of the appendix from the files of the Armed Forces Institute of pathology from 1970 to 1998. There were also one benign schwannoma, one diffuse neurofibroma with neurofibromatosis 1, one leiomyosarcoma in a child with hiv infection, and one inflammatory fibroid polyp. The four appendiceal GISTs occurred in adult males 56-72 years of age (mean 63 years). Two tumors occurred in patients who had surgery for appendicitis-like symptoms: one was an incidental finding during surgery for a malignant gastric epithelioid GIST and one was an incidental autopsy finding. Only one of the two appendices operated for symptoms had acute inflammation, and a polypoid GIST projected outward from the proximal part of appendix. Three tumors were partially obliterating nodules, eccentrically expanding the appendiceal wall. All four were spindle cell tumors, and three of them contained extracellular collagen globules (skeinoid fibers); none had atypia or mitotic activity (<1/50 high power fields). Immunohistochemically, two tumors studied were positive for CD117 (KIT), and two were positive for CD34. The tumors were negative for alpha-smooth muscle actin and S-100 protein. Follow-up revealed death from cardiovascular disease in one case (4 years after appendectomy) and liver failure because of malignant gastric epithelioid GIST metastatic to liver in another case 15 years after the appendectomy. This report documents the rare occurrence of CD117-positive GISTs as primary appendiceal tumors.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
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