Decreased interstitial cells of Cajal in the neorectum after anterior resection of the rectum

BACKGROUND/AIMS: Patients who have undergone anterior resection for rectal carcinoma often complain of anorectal and defecatory dysfunction postoperatively. The aim of this study was to examine the expression of interstitial cells of Cajal (ICCs) in the sigmoid colon used for constructing the neorectum after anterior resection of the rectum. METHODOLOGY: As the neorectum group, we assessed 12 patients with local and anastomotic recurrence or new neoplasm in the neorectum after anterior resection of the rectum. The control group consisted of 16 patients who underwent sigmoid colon resection for sigmoid colon carcinoma. All resected specimens were investigated with immunohistochemical staining, using c-kit antibody for ICCs. The correlation between the number of ICCs and defecatory symptoms was assessed for the neorectum. RESULTS: The total number of ICCs significantly decreased in the neorectum group as compared to the control group. In particular, a significant difference was noted between the two groups as to the number of ICCs found between the layers of the myenteric plexus in histological studies, as well as in the circular and longitudinal muscles. There was no correlation between the number of ICCs and the time interval from the initial anterior resection to the resection of the neorectum, nor was there any relationship between the number of ICCs and defecatory symptoms. CONCLUSIONS: The expression of ICCs in the neorectum was reduced in the early stages after anterior resection of the rectum. Expression of ICCs in the neorectum did not recover to preoperative levels over time.     

The pathogenesis of idiopathic megacolon

BACKGROUND: Even today, the pathogenesis of idiopathic megacolon is still a subject of controversy. Anomalies of the gastrointestinal autonomous nervous system or of the smooth muscle of the muscularis propria are being considered. METHODS: Sixty-three idiopathic megacolon resections between 1997 and June 2004 were investigated. The native specimens were coiled caudo-cranially and cryostat-cut. Connective tissue was stained with picric acid/Sirius red after Delauney fixation. Immunohistochemistry was performed for collagen types I, II, III and IV, as well as smooth muscle actin, vimentin, desmin fibronectin and CD117 for interstitial cells of Cajal. The enteric nervous system was examined by enzyme histochemistry for acetylcholine-esterase, lactate dehydrogenase, succinic dehydrogenase and nitroxide synthase. RESULTS: Histologically, idiopathic megacolon was characterized by a total atrophy of the collagenous tendinous connective tissue membrane of the myenteric plexus and the tendinous collagen fibre net of the muscularis propria. Immunohistochemically, mainly collagen type III was missing in the muscularis propria. Interestingly, the incidence of idiopathic megacolon in those of the female sex was seven times more frequent than in the male sex. The myenteric plexus was normal in the majority of patients. Interstitial cells of Cajal, collagen II and IV, as well as smooth muscle actin, desmin and fibronectin showed no consistent alteration. CONCLUSION: A normally structured tendinous fibre net of muscularis propria is an essential prerequisite for effective gut peristalsis. Atrophy of the tendinous fibre net abolishes peristalsis and allows for unlimited distension of the colon. A diagnosis of idiopathic megacolon can reliably be made on a collagen stain. The normal findings of myenteric plexus support the hypothesis that a primary metabolic defect of muscularis propria may be the underlying cause of idiopathic megacolon.     

Human hepatic stem-like cells isolated using c-kit or CD34 can differentiate into biliary epithelium

BACKGROUND & AIMS: Recent reports suggest that after bone marrow transplantation into rodents and humans, hematopoietic stem cells migrate into the liver and give rise to oval cells, hepatocytes, and biliary epithelial cells. We investigated this hypothesis further in the human liver using the hematopoietic markers c-kit and CD34. METHODS: Immunofluorescence confocal microscopy was performed using cytokeratin 19 (CK-19; biliary cell marker) with either c-kit or CD34. Immunomagnetic separation was then used to select c-kit- or CD34-positive cells. After attachment, cells were cultured for up to 7 days, and their growth and phenotypic characteristics were examined. RESULTS: In cirrhotic tissue, c-kit- or CD34-positive cells were located in the portal tracts surrounding bile ducts. Occasionally c-kit- (but not CD34-) positive cells that coexpressed CK-19 were observed integrated into bile ducts. In vitro, immunoisolated c-kit or CD34 cells gave rise to colonies of at least 2 morphologies expressing CK-19 or CD31 (endothelial cell marker). CD34- or c-kit-positive cells with similar properties were also isolated from normal liver. CONCLUSIONS: These findings indicate that cells present in human liver that express the markers c-kit or CD34 have the capacity to differentiate into biliary epithelial cell lineage and may therefore represent human biliary epithelial progenitor cells.     

Expression of the YB5.B8 antigen (c-kit proto-oncogene product) in normal human bone marrow.

The c-kit proto-oncogene product is a member of the family of growth factor receptors with intrinsic tyrosine kinase activity. In the mouse c-kit maps to the W locus, which is known to be of central importance in hematopoiesis. Monoclonal antibody (MoAb) YB5.B8, which was raised against peripheral blood blast cells from a patient with acute myeloid leukemia (AML), was recently shown to bind to the extracellular domain of the c-kit product. This antibody does not bind detectably to normal peripheral blood cells and identifies a sub-group of AML patients with poor prognosis. We have used MoAb YB5.B8 to study the expression of c-kit by normal human bone marrow cells by immunofluorescence and flow cytometry, and to isolate multipotential and erythroid colony-forming cells. In a series of 11 normal adult bone marrow specimens, MoAb YB5.B8 bound to 4.0% +/- 1.8% of the cells in the low-density fraction. Dual-labeling experiments were performed with YB5.B8, and CD33, CD34, and CD10 MoAbs. Three populations of cells binding YB5.B8 could be identified based on their pattern of coexpression of the other markers; ie, YB5.B8+/CD34+/CD33-, YB5.B8+/CD34+/CD33+ and YB5.B8+/CD34+/CD33+. These populations had distinctive two-dimensional light scatter characteristics and are likely to correspond to precursor colony-forming cells, colony-forming cells, and maturing mast cells, respectively. No cells binding both YB5.B8 and an MoAb to the early lymphoid marker CD10 were found, implying that most early lymphoid cells do not express c-kit. MoAbs to the c-kit protein should prove valuable in multimarker studies of human hematopoietic stem and progenitor cells. Definition of a reference range of c-kit expression in normal human bone marrow will provide a sound basis for further studies of this marker in diagnosis and prognosis in AML.     

Primitive acute myeloid leukemia cells with long-term proliferative ability in vitro and in vivo lack surface expression of c-kit (CD117)

A hierarchy of progenitor cells is thought to exist in human acute myeloid leukemia (AML), with only the most primitive cells capable of proliferating to maintain the malignant clone. To further characterize this AML cell hierarchy, we evaluated the coexpression of CD34 and c-kit (CD117) on cells that are capable of long-term proliferation in vitro and in vivo.AML cells were sorted for coexpression of CD34 and c-kit (CD117) using two c-kit monoclonal antibodies (mAbs), clones 95C3 and 104D2. Sorted subfractions were evaluated for the ability to produce colony-forming units (CFU) for up to 8 weeks in suspension culture (SC) and for the capacity to repopulate NOD/SCID mice.When expression of c-kit on blood cells from 19 AML patients at diagnosis was compared using both mAbs, expression defined by 104D2 (34% +/- 6% c-kit(+)) was somewhat higher than that defined using 95C3 (18% +/- 4%). AML cells were sorted for coexpression of CD34 and c-kit using both c-kit mAbs, and the subfractions were assayed in vitro and in vivo. Whereas the majority of AML blast cells lacked expression of CD34, most AML cells capable of proliferating to produce CFU after 4 to 8 weeks in SC were CD34(+)/c-kit(-). Cultures of sorted CD34(+)/c-kit(-) cells, supplemented with steel factor, were composed of a large proportion (18% to 87%) of CD34(+)/c-kit(+) cells after 1 week, suggesting that either c-kit expression was upregulated or CD34(+)/c-kit(+) cells were produced. Moreover, the CD34(+)/c-kit(-) subfraction was found to be capable of responding to steel factor alone to produce CFU after 4 weeks in SC. In most AML patients tested (11/15), the only sorted subfraction capable of engrafting NOD/SCID mice was CD34(+)/c-kit(-). The CD34(+)/c-kit(+) subfraction from only 2 of the 15 patients and CD34(-) cells from 3 patients also engrafted the NOD/SCIDs. Only the CD34(+)/c-kit(+) subfraction of normal bone marrow engrafted.These studies suggest that primitive AML cells capable of long-term proliferation in vitro and NOD/SCID repopulation differ from primitive normal progenitor cells in their lack of surface expression of c-kit.     

Evaluation of specific herpes DNA viruses in idiopathic megarectum and idiopathic megacolon

Purpose: The aetiology of idiopathic megarectum and idiopathic megacolon is unknown. A previous study in patients with chronic idiopathic intestinal pseudo-obstruction, a condition also associated with a dilated gut, identified the possible involvement of herpes viruses. This study therefore aimed to determine whether these viruses may also be implicated in the pathogenesis of these conditions. Methods: Resected large bowel from three patients with idiopathic megarectum and three patients with idiopathic megacolon were studied. Histology for viral inclusions and nested polymerase chain reaction (PCR) using specific primers for cytomegalovirus, Epstein-Barr virus, herpes simplex virus type 1 and varicella zoster virus was performed. DNA was extracted from paraffin-embedded blocks by proteinase K and phenol chloroform extraction. Results: Viral inclusions were not seen. PCR failed to identify DNA of the four herpes viruses tested. Conclusion: Patients with idiopathic megarectum or idiopathic megacolon may have subtle abnormalities of the enteric innervation, but these do not appear to be attributable to the neurotropic effects of the herpes viruses studied. Accepted: 10 February 1998     

大鼠部分肝移植后自体骨髓干细胞动员的研究

目的 探讨大鼠部分肝移植后骨髓干细胞动员的情况。方法 建立大鼠性别交叉部分肝移植模型，分为部分肝移植组、全肝移植组和假手术组，分别与术后1、3、5、7d取标本。用流式细胞法检测骨髓中干细胞标记的细胞群体的数量变化，荧光原位杂交检测移植肝脏内Y染色体特异的Sry基因的表达，免疫组织化学法检测移植肝脏内干细胞标志CD34，c—kit和Thy-1．1的表达。结果 与全肝移植组相比，部分肝移植组术后第1天，骨髓细胞中，β2微球蛋白（β2m）／Thy-1．1^＋，CD45^＋／CD34^＋有不同程度的升高，然后呈递减趋势。免疫组织化学检测汇管区和炎性灶周围可见CD34、c—kit和Thy-1．1单个核细胞表达，并于第5至7天后减少。同时免疫组织化学双染可检出CD34^＋／CD45^＋细胞。全肝移植组汇管区CD34、c—kit和Thy-1．1表达较少，假手术组CD34、c-kit和Thy-1．1偶见表达。在部分肝移植物可检出Sry^＋细胞，但Srg^＋／CD34^＋，Sry^＋／Thy-1．1^＋细胞较少。全肝移植组Sry^＋偶见。结论 部分肝移植中，骨髓源性的干细胞发生动员；同时肝内有干细胞被激活，其中外源性干细胞较少。     

Colectomy for idiopathic megarectum and megacolon.

The outcome in 40 patients who underwent colectomy for idiopathic megacolon and megarectum over an 18 year period was evaluated. All patients had a radiologically dilated bowel and a bowel frequency of less than two per week. Twenty two patients had a caecorectal anastomosis, 11 had an ileorectal anastomosis (including one with a previous caecorectal anastomosis and four with a previous sigmoid resection), and seven had a sigmoid resection. The mean (range) age at operation was 35 (17-69) years. All three operations resulted in a normal bowel frequency in more than 80% of patients but no patient with an ileorectal anastomosis experienced recurrent constipation. Thirty four patients experienced pain preoperatively and this was still present in 14 patients postoperatively. One patient died and four required subsequent laparotomy for bowel obstruction. The functional outcome in patients with dilatation of the whole colon and in those with dilatation of the left colon did not differ. Subsequent surgery for constipation was performed in three patients. Colectomy offers good results with few complications in the treatment of idiopathic megacolon, and an ileorectal anastomosis is the preferred operation.     

Hirschsprung's disease and idiopathic megacolon in adults and adolescents

The distinction between Hirschsprung's disease and idiopathic megacolon in childhood dates from the classic clinical, radiological, and histological studies of Bodian, Stephens, and Ward. This article describes clinical experience over 15 years of 94 patients in whom megacolon of these two types was recognised for the first time after the age of 10, to illustrate the problems of diagnosis and treatment in later years. Just as it is now recognised that patients with the clinical characteristics of Hirschsprung's disease may have one of several abnormalities of the myenteric plexus, including not only absence of ganglion cells, but also patchy or zonal loss, abnormal neurones or neuronal dysplasia, so idiopathic megacolon may also be a heterogeneous group of cases. This paper suggests on clinical grounds that those patients with idiopathic megacolon whose symptoms start in childhood differ from those whose symptoms develop in later years.     

A planar gastrointestinal stromal tumor replacing the proper muscle layer causing fecaloma and perforation in the sigmoid colon: a case report and literature review

A 72-year-old Japanese male with acute abdomen underwent emergency surgery for a preoperative diagnosis of stercoral colonic perforation of the sigmoid colon. A pathological examination revealed a proliferating spindle cell lesion that surrounded the perforation and replaced the muscularis propria without any mass formation. The spindle cells were positive for KIT and CD34 by immunohistochemistry, and somatic mutation of the c-kit gene was found using genomic DNA extracted from the lesion. We diagnosed the spindle cell lesion as a planar gastrointestinal stromal tumor (GIST). We speculate that perforation of the sigmoid colon in this case may be caused by the stasis of stool resulting from abnormal peristalsis of the lesional site. Two other similar cases have been reported in the literature, and showed good prognoses. Although their pathogenesis is unclear, planar GISTs should be considered as a possible cause of idiopathic or stercoral colonic perforation.     

Possible stem cell origin of human cholangiocarcinoma

AIM: To investigate the expression of CD34 and c-kit (receptor of stem cell factor) in cholangiocarcinoma. METHODS: Fifteen cases of intrahepatic cholangiocarcinoma and 17 cases of extrahepatic cholangiocarcinoma were studied in this experiment. Using Envision detection system, paraffin-embedded sections of the resected cholangiocarcinoma tissue were stained with antibodies against CD34 and c-kit, respectively. The sections were counterstained with hematoxylin, and the results were examined under light microscope. Normal tonsil and mammary tissues were used as positive controls for CD34 and c-kit, respectively. RESULTS: CD34 was positive in all sections, but only in capillary endothelial cells of tumor tissue. No cholangiocarcinoma cells were positive for CD34. In one case of extrahepatic cholangiocarcinoma, a few tumor cells (about 5%) were immunoreactive with c-kit. CONCLUSION: CD34 or c-kit positive cells in liver tissue may represent liver stem cells, as they can differentiate into mature biliary cells in vitro. The expression of c-kit by some cholangiocarcinoma cells suggests that cholangiocarcinoma might originate from liver stem cells. However, other mechanisms of hepatocarcinogenesis, such as de-differentiation of mature cholangiocytes, may also exist.     

Interstitial cells of Cajal in the human fetal small bowel as shown by c-kit immunohistochemistry

Background—Interstitialcells of Cajal (ICCs) express the tyrosine kinase receptor c-kit, whichis required for their development and spontaneous pacemaker activity inthe bowel. From murine models it has been proposed that ICCs do notdevelop until after birth, but more recent findings indicate that c-kitis expressed early in the embryonic period. The temporal development ofICCs in the human gut remains unknown.
Aim—To investigateICCs in the human fetal small bowel using c-kit immunohistochemistry.
Subjects—Small bowelspecimens were obtained at post mortem examination of 16 fetuses andnine neonates, eight of whom were premature, born at gestational agesof 13 to 41 weeks, without gastrointestinal disorders.
Methods—Immunohistochemicalanalysis was performed on material fixed in formalin and embedded inparaffin. The specimens were exposed to antibodies raised against c-kit(an ICC marker) and neurone specific enolase (a general neuronalmarker). The ABC complex method was used to visualise binding ofantibodies to the corresponding antigens.
Results—c-kitimmunoreactive cells were visualised from 13 weeks of gestation. Theimmunoreactivity was mainly localised in association with the myentericplexus. From about 17-18 weeks of gestation, the ICCs formed a layeralong the myenteric plexus, whereas this layer appeared to be disruptedat 13-16 weeks of gestation.
Conclusions—ICCs arec-kit immunoreactive at least from a gestational age of 13 weeks inthe human fetal small intestine. From 17-18 weeks of gestation untilbirth, they form a continuous layer around the myenteric ganglia.

Keywords:interstitial cells of Cajal; c-kit; myentericplexus; human; fetal; development

     

Histopathological features and clinical course of the gastrointestinal stromal tumors

BACKGROUND/AIMS: C-kit expression is a sensitive marker for a specific group of mesenchymal tumors of the gastrointestinal tract, gastrointestinal stromal tumors, the histogenesis and prognosis of which are uncertain. METHODOLOGY: We have investigated the expression of c-kit by immunohistochemical analysis (APAAP method) in 12 out of 13 cases of mesenchymal gastrointestinal neoplasms operated from January 1991 to December 1998, in which the follow-up data were fully available. Furthermore, the c-kit expression was correlated both with the expression of vimentin, CD34 and the mitotic rate, and with the expression of muscle (muscle-specific actin-HHF35 and desmin) or neural (neuron-specific enolase) differentiation markers. RESULTS: C-kit was expressed in all 12 cases (100%). Two different patterns of expression were observed: cytoplasmic in 7 (58.3%) cases and nuclear in 3 (25%) cases; in 2 (16.7%) cases both cytoplasmic and nuclear immunostaining was detected. Three (60%) out of the five cases showing a nuclear c-kit expression were also neuron-specific enolase positive, whereas none of the cases showing an exclusively cytoplasmic c-kit expression was neuron-specific enolase positive. The correlation between the two patterns of c-kit expression and the follow-up data have shown a trend towards a better prognosis in gastrointestinal stromal tumors with a nuclear c-kit immunostaining and neuron-specific enolase positivity, but the relatively low number of cases does not allow us to draw conclusions. In gastrointestinal stromal tumors the mitotic rate (> 2 x 10 HPF vs. < 2 x 10 HPF) is related with statistically significant differences (P < 0.05) to the 5-year survival (0% vs. 80%, respectively). CONCLUSIONS: These findings, together with the already known c-kit nuclear immunostaining in normal adrenal medullary cells, suggest that a nuclear c-kit expression in gastrointestinal stromal tumors is consistent with a neural differentiation. In this study the mitotic rate has demonstrated a significant influence on the prognosis of gastrointestinal stromal tumors.     

Correlation of c-kit expression and cell cycle regulation by transforming growth factor-beta in CD34+ CD38- human bone marrow cells

To investigate the relationship between c-kit expression and cell cycle regulation by endogenous transforming growth factor-beta (TGF-beta) in human bone marrow hematopoietic progenitor cells, CD34+ CD38- c-kit(low/-) and CD34+ CD38- c-kit(high) populations were cultured in stem cell factor, thrombopoietin, interleukin-3 (IL-3), IL-6, granulocyte colony-stimulating factor, granulocyte/macrophage colony-stimulating factor and anti-TGF-beta, and analyzed for cell cycle status. Arrest in G0/G1 was most prominent in the precultured CD34+ CD38- c-kit(low/-) subset (95.62 +/- 4.15%). While postcultured CD34+ CD38- c-kit(high) cells initiated from CD34+ CD38- c-kit(high) cells entered cell cycle within 36 hr, postcultured CD34+ CD38- c-kit(low/-) cells initiated from CD34+ CD38- c-kit(low/-) cells remained dormant until 36 hr and entered cell cycle within 90 hr. Anti-TGF-beta increased the percentage of S/G2M phase postcultured CD34+ CD38- c-kit(high) cells (from 19.08 +/- 11.95 to 47.04 +/- 2.93%), but no significant change was observed in postcultured CD34+ CD38- c-kit(low/-) cells. These results suggest that endogenous TGF-beta plays an important role in the cell cycle arrest of c-kit(high) but not c-kit(low/-) cells in CD34+ CD38- cells, which proliferate without undergoing differentiation. The different regulatory mechanism of cell cycle entry of the CD34+ CD38- c-kit(high) and CD34+ CD38- c-kit(low/-) subsets might be the result of differences in their sensitivity to endogenous TGF-beta.     

Effects of Lizhong Tang on cultured mouse small intestine interstitial cells of Cajal

AIM:To investigate the effects of Lizhong Tang,an herbal product used in traditional Chinese medicine,on mouse small intestine interstitial cells of Cajal(ICCs).METHODS:Enzymatic digestions were used to dissociate ICCs from mouse small intestine tissues.The ICCs were morphologically distinct from other cell types in culture and were identified using phase contrast microscopy after verification with anti c-kit antibody.A whole-cell patch-clamp configuration was used to record potentials(current clamp) from cultured ICCs.All of the experiments were performed at 30-32 ℃.RESULTS:ICCs generated pacemaker potentials,and Lizhong Tang produced membrane depolarization in current-clamp mode.The application of flufenamic acid(a nonselective cation channel blocker) abolished the generation of pacemaker potentials by Lizhong Tang.Pretreatment with thapsigargin(a Ca 2+-ATPase inhibi-tor in the endoplasmic reticulum) also abolished the generation of pacemaker potentials by Lizhong Tang.However,pacemaker potentials were completely abolished in the presence of an external Ca 2+-free solution,and under this condition,Lizhong Tang induced membrane depolarizations.Furthermore,When GDPβ-S(1 mmol/L) was in the pipette solution,Lizhong Tang still induced membrane depolarizations.In addition,membrane depolarizations were not inhibited by chelerythrine or calphostin C,which are protein kinase C inhibitors,but were inhibited by U-73122,an active phospholipase C inhibitors.CONCLUSION:These results suggest that Lizhong Tang might affect gastrointestinal motility by modulating pacemaker activity in interstitial cells of Cajal.     

Clinicopathologic, phenotypic, and genotypic characteristics of gastrointestinal mesenchymal tumors.

BACKGROUND & AIMS: Variability in the frequency of KIT mutations in gastrointestinal mesenchymal tumors has been reported in the literature, and their prognostic value remains uncertain. This retrospective multicenter study included 276 patients with gastrointestinal mesenchymal tumors. METHODS: We detected c-kit and CD34 protein expression by immunohistochemistry. Mutations in exons 11 and 9 of KIT and exons 12 and 18 of PDGFR were detected by length analysis of polymerase chain reaction products and direct DNA sequencing. RESULTS: Eighty-seven percent of the tumors analyzed were c-kit positive, with gastric tumors expressing CD34 more frequently than other tumors (86% vs. 52%; P < 0.001). KIT exon 11 mutations were detected in 90 of 179 (50.3%) of c-kit-positive and 12% of c-kit-negative tumors. These mutations showed variation in their length and location. Mutations were heterozygous in 94% of cases. Mutations were more frequent in CD34( +) tumors than in CD34( -) tumors ( P < 0.01), and 9% of tumors had a second mutation in exon 11. Mutations in exon 9 of KIT were present in 5.1% of the gastrointestinal stromal tumors, and mutations of the PDGFR were present in 11% of the KIT -nonmutated tumors. Patient's age, the primary location, size, necrosis, and mitotic counts of tumors were associated with metastases in c-kit-positive tumors. However, mitotic activity was the only independent factor identified in multivariate analysis ( P < 0.001). KIT mutations were slightly more frequent in metastatic than in nonmetastatic tumors (61% vs. 46%; P = 0.06). Deletions of codons 562-579 were more strongly associated with metastases than were deletions of codons 550-561 ( P = 0.0001). CONCLUSIONS: Mutations in KIT or PDGFR were detected in 58.4% of the c-kit-positive and also in some c-kit-negative tumors.     

Effect of pentagastrin on the motor activity of the dilated and nondilated sigmoid and rectum in Chagas' disease

In order to evaluate the effect of pentagastrin on the motor activity of the sigmoid and rectum in patients with Chagas' disease, manometric studies were performed on 22 chagasic patients, 11 without and 11 with megacolon, and 11 control subjects. Pentagastrin had a stimulating effect on the sigmoid and rectum in control subjects as well as in chagasic patients without megacolon. In chagasic patients with megacolon, pentagastrin had no effect on sigmoid or rectum motility, probably as a result of the intrinsic denervation known to occur in this disease. The findings suggest that the motor effect of pentagastrin on the human sigmoid and rectum depends on the myenteric nervous pathways.     

Gastric calcifying fibrous tumor removed by endoscopic submucosal dissection

The World Health Organization describes calcifying fibrous tumors(CFTs) as rare, benign lesions characterized by hypocellular, densely hyalinized collagenization with lymphoplasmacytic infiltration. These tumors rarely involve the gastrointestinal(GI) tract. A routine endoscopic upper gastrointestinal screen detected a 10-mm submucosal tumor(SMT) in the lesser curvature of the lower corpus of the stomach of an apparently healthy, 37-year-old woman with no history of Helicobacter pylori infection. Endoscopic ultrasonography(EUS) localized the internally isoechoic, homogeneous SMT mainly within the submucosa. Malignancy was ruled out using endoscopic submucosal dissection(ESD). A pathological examination confirmed complete resection of the SMT, and defined a hypocellular, spindle-cell tumor with a densely hyalinized, collagenous matrix, scattered lymphoplasmacytic aggregates as well as a few psammomatous, dystrophic calcified foci. The mass was immunohistochemically positive for vimentin and negative for CD117(c-kit protein), CD34, desmin, smooth muscle actin(SMA) and S100. Therefore, the histological findings were characteristic of a CFT. To date, CFT resection by ESD has not been described. This is the first case report of a gastric calcifying fibrous tumor being completely resected by ESD after endoscopic ultrasonography.     

A rare case of achalasia coexistent with sigmoid megacolon and associated with epilepsy

A case of achalasia coexistent with sigmoid megacolon in a 38-year-old man with known epilepsy is described. The patient was referred to the Ryukyu University Hospital with a 4-year history of dysphagia and heartburn and a 1-year history of abnormal bowel movement. On admission, upper gastrointestinal (GI) series demonstrated a dilated, tortuous thoracic esophagus with a flask-type configuration. Barium enema studies showed a dilated sigmoid colon from the rectosigmoid junction to the descending colon. Myotomy (modified Jekler-Lhotka's procedure) for achalasia and simple sigmoidectomy for sigmoid megacolon were carried out. The biopsied wall of the narrowed esophageal segment at operation showed decreased numbers of ganglion cells in Auerbach's plexus and atrophy of the muscle fibers. The resected dilated sigmoid colon revealed degeneration and markedly decreased numbers of ganglion cells in Auerbach's and Meissner's plexuses. The patient's postoperative course was uneventful and he has been doing well since surgery. The present case is very interesting and to our knowledge, such a case is rare in the literature. We believe that the abnormalities of the ganglion cells may be due to the same etiologic factor as the sigmoid megacolon. The association of the two pathologic processes is discussed, together with a brief review of the literature.