Mee Joo

Pathologic features of ulcerative colitis in patients with primary sclerosing cholangitis: a case-control study.

Background The pathologic features of ulcerative colitis (UC) in patients with primary sclerosing cholangitis (PSC) are, essentially, unknown. One previous clinical study suggested that UC-PSC patients reveal a high rate of rectal sparing and backwash ileitis. The purpose of this study was to systematically evaluate the pathologic characteristics and distribution of colonic disease in UC-PSC patients and to compare the results with a matched control group of UC patients without PSC. Methods Forty UC-PSC patients and 40 matched UC patients without PSC (controls) were identified from the files of 3 hospitals between the years 1989 and 2005. Clinical, endoscopic, and follow-up data (including incidence of pouchitis) were evaluated, and a detailed pathologic evaluation of biopsy and resection specimens (when available) was performed in a blinded fashion. The degree of activity and chronicity in mucosal biopsies and/or tissue from resection specimens was graded on a 5-point grading system (0 to 4), and each portion of the colon (cecum, ascending colon, transverse colon, descending colon, rectum) was assessed separately. Rectal sparing and patchiness of disease were evaluated, and scored as either absolute or relative depending on the complete absence of inflammatory disease in the former, or less inflammatory disease in the rectum compared with other parts of the colon in the latter. Results In this matched case-control study, UC-PSC patients presented at a significantly earlier age (24.5 y), had a higher prevalence rate of pancolitis (85%), and an overall significantly lower grade of inflammation in the colon (mean grade: 2.09±0.085) compared with UC controls (mean age: 33.8 y, pancolitis: 45%, inflammation grade: 2.59±0.92, P<0.05 for all comparisons). The incidence rate of absolute and relative rectal sparing (27.5%) and of patchy inflammatory disease proximal to the rectum (5.7%) was not significantly different between the UC-PSC cases and the UC controls (25% and 7.9%, respectively). UC-PSC patients had a higher prevalence rate of ileitis (35.7%) and pouchitis (42.8%), but the values were not significantly different from controls (26.9% and 26.6%, respectively). The incidence rate of dysplasia was similar between the 2 patient groups. Conclusions UC patients with PSC show a propensity for more extensive, but less active, disease but are otherwise characterized by similar pathologic findings compared with UC patients without PSC. Rectal sparing and patchy disease activity is not characteristic of UC patients with PSC.

Multiple gastrointestinal stromal tumors: Clinicopathologic and genetic analysis of 12 patients.

Multiple gastrointestinal stromal tumors (GISTs) are extremely rare and usually associated with type 1 neurofibromatosis and familial GIST. The aim of this study was to investigate the clinical, phenotypic, and genetic characteristics of multiple GISTs to gain insights into their underlying pathogenesis and clinical behavior. Forty-seven paraffin blocks of multiple GISTs from 12 patients were analyzed. Genomic DNA was extracted from the tumor and normal mucosa and mutations for 4 exons of KIT gene and 3 exons of PDGFRA gene were determined. Among 12 patients with multiple GISTs, 5 were sporadic, 2 were familial with germline mutations of KIT gene, and 5 were associated with type 1 neurofibromatosis. All but 1 sporadic and familial multiple GISTs showed mutations of KIT gene shared by the same mutation on each GIST mass within a patient. But in 1 sporadic case, different types of KIT mutations were observed. Two familial multiple GIST cases showed diffuse involvement of the gastrointestinal tract with diffuse hyperplasia of interstitial cell of Cajal. Multiple GISTs associated with type 1 neurofibromatosis were located in the jejunum and harbored no mutations of KIT or PDGFRA. Different types of KIT gene mutation found in our case raise a possibility that recurrence of GISTs within a gastrointestinal tract may have a chance to be a rare occurrence of multiple primary GISTs instead of true recurrence. Multiple GISTs show unique clinical, phenotypic, and genotypic characteristics that are dependent on the particular underlying mechanisms, but the overall prognosis is favorable regardless of the numbers or phenotype of GISTs.

Primary gastrointestinal clear cell sarcoma: report of 2 cases, one case associated with IgG4-related sclerosing disease, and review of literature

Clear cell sarcoma (CCS) is a distinctive soft tissue sarcoma that shows melanocytic differentiation. Primary gastrointestinal (GI) CCSs have been rarely reported, but to our knowledge, no association between GI CCSs and immunoglobulin G4 (IgG4)-related sclerosing disease has been described in the literature. We experienced 2 cases of CCS that arose in the small intestine and metastasized to the liver. Histologic features and immunophenotype were typical of CCS. One of them showed a unique peritumoral sclerosing inflammatory reaction, which was highly reminiscent of IgG4-related sclerosing inflammatory disease. Dense lymphoplasmacytic infiltration with extensive sclerosis and obliterative phlebitis was observed in the immediate vicinity of the primary and metastatic tumors, but not in the distant areas from the tumor. The average number of IgG4-positive plasma cells was more than 50 per high-power field. We report 2 cases of primary GI CCS with one case showing a unique peritumoral IgG4-related lymphoplasmacytic sclerosing inflammation.

Helicobacter heilmannii-associated Gastritis: Clinicopathologic Findings and Comparison with Helicobacter pylori-associated Gastritis

The aims of this study were to evaluate the clinicopathologic features of Helicobacter heilmannii-associated gastritis and to compare H. heilmannii-associated gastritis with H. pylori-associated gastritis. We reviewed 5,985 consecutive gastric biopsy specimens. All cases of chronic gastritis with Helicobacter infection were evaluated with the Updated Sydney System, and the grades of all gastritis variables were compared between H. heilmannii-associated gastritis and H. pylori-associated gastritis groups. There were 10 cases of H. heilmannii-associated gastritis (0.17%) and 3,285 cases of H. pylori-associated gastritis (54.9%). The organisms were superficially located within the mucous layer without adhesion to epithelial cells. Interestingly, in one case many intracytoplasmic H. heilmannii organisms were observed in parietal cells with cell damage. A case of low-grade mucosa-associated lymphoid tissue (MALT) lymphoma concomitant with H. heilmannii infection was detected. Compared to H. pylori-associated gastritis, H. heilmannii-associated gastritis showed less severe neutrophilic activity (p<0.0001), mononuclear cell infiltration (p=0.0029), and endoscopic findings of chronic gastritis devoid of erosion or ulcer (p=0.0309). In conclusion, we present the detailed clinicopathologic findings of H. heilmannii-associated gastritis compared to H. pylori-associated gastritis. H. heilmannii-associated gastritis is uncommon and milder than H. pylori-associated gastritis, however it may be noteworthy with respect to the development of MALT lymphoma.

IgG4-related sclerosing esophagitis: a case report

decided to initially use an OVESCO (over-the-scope clip) with an 11-mm diameter that partially occluded the fistula and worked as an anchor point for the posterior placement of a self-expandable covered metal stent (20-mm diameter and 8-cm length) (Figs. 2-4). At the end of the procedure, there was a good flow of contrast to the stomach, with no evidence of the fistulous tract (Figs. 5 and 6). At the 48-hour evaluation, there was proper positioning of the clip and stent and no evidence Figure 5. Stent and endoclip in situ.

Expression of Ep-CAM in intestinal metaplasia, gastric epithelial dysplasia and gastric adenocarcinoma

Background:  The epithelial cell adhesion molecule (Ep‐CAM) is widely associated with human carcinomas. However, the expression and distribution of Ep‐CAM in gastric premalignant and malignant lesions are not well known.

Diagnosis of gastric epithelial neoplasia: Dilemma for Korean pathologists.

The histopathological diagnosis of gastric mucosal biopsy and endoscopic mucosal resection/endoscopic submucosal dissection specimens is important, but the diagnostic criteria, terminology, and grading system are not the same in the East and West. A structurally invasive focus is necessary to diagnose carcinoma for most Western pathologists, but Japanese pathologists make a diagnosis of cancer based on severe dysplastic cytologic atypia irrespective of the presence of invasion. Although the Vienna classification was introduced to reduce diagnostic discrepancies, it has been difficult to adopt due to different concepts for gastric epithelial neoplastic lesions. Korean pathologists experience much difficulty making a diagnosis because we are influenced by Japanese pathologists as well as Western medicine. Japan is geographically close to Korea, and academic exchanges are active. Additionally, Korean doctors are familiar with Western style medical terminology. As a result, the terminology, definitions, and diagnostic criteria for gastric intraepithelial neoplasia are very heterogeneous in Korea. To solve this problem, the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists has made an effort and has suggested guidelines for differential diagnosis: (1) a diagnosis of carcinoma is based on invasion; (2) the most important characteristic of low grade dysplasia is the architectural pattern such as regular distribution of crypts without severe branching, budding, or marked glandular crowding; (3) if nuclear pseudostratification occupies more than the basal half of the cryptal cells in three or more adjacent crypts, the lesion is considered high grade dysplasia; (4) if severe cytologic atypia is present, careful inspection for invasive foci is necessary, because the risk for invasion is very high; and (5) other structural or nuclear atypia should be evaluated to make a final decision such as cribriform pattern, papillae, ridges, vesicular nuclei, high nuclear/cytoplasmic ratio, loss of nuclear polarity, thick and irregular nuclear membrane, and nucleoli.

Nodular lymphoid hyperplasia and histologic changes mimicking celiac disease, collagenous sprue, and lymphocytic colitis in a patient with selective IgA deficiency

Selective IgA deficiency is the most common primary immunoglobulin deficiency. The clinical manifestations of selective IgA deficiency, including gastrointestinal (GI) complications, are rare and typically milder than those seen with common variable immunodeficiency or X-linked agammaglobulinemia. We present a rare case of selective IgA deficiency that shows a number of interesting histological features in the GI tract, including diffuse nodular lymphoid hyperplasia involving the entire small and large intestine, celiac disease-like and collagenous sprue-like changes in the small intestine, as well as lymphocytic colitis pattern. However, this patient had no particular GI symptoms suggestive of celiac sprue or microscopic colitis. These findings suggest that the GI tract in patients with selective IgA deficiency can show peculiar histologic changes that mimic celiac disease, collagenous sprue, or lymphocytic colitis, which may be a pattern of injury related to infection or immunoglobulin immunodeficiency-associated autoimmune phenomena.

Idiopathic segmental ureteritis, misdiagnosed as ureteral cancer preoperatively : A case report with literature review

A 53‐year‐old man presented with right flank pain for 6 days. Computerized tomography revealed a 3 cm long segment of ureteral narrowing with wall thickening and hydronephrosis, suspicious for ureteral cancer. Under the clinical diagnosis of ureteral carcinoma a right nephroureterectomy was performed. The wall of the distal ureter, 2.5 cm from the bladder cuff, had a luminal‐narrowing, firm mass‐forming lesion with abrupt transition from the adjacent ureter. Histologically, the resected ureteral mass showed transmural fibrosing, chronic inflammation with numerous plasma cells, epithelioid granulomas, and obliterative phlebitis. Histological findings were consistent with idiopathic segmental ureteritis (ISU) with differential diagnoses of IgG4‐related sclerosing disease, including lymphoplasmacytic inflammatory pseudotumor (IPT) and idiopathic retroperitoneal fibrosis. IgG4 immunostaining in this case was barely positive, excluding the possibility of IgG4‐related IPT. Although the majority of luminal obliterated segmental lesions of the ureter are neoplastic in nature, non‐neoplastic inflammatory processes as seen in this case may occur in the ureter, causing diagnostic confusion with true neoplasms. Herein we report a rare case of ISU that was clinically misdiagnosed as malignancy preoperatively. ISU of the current case may be an IgG4‐unrelated subtype of IPT.

Gastrointestinal stromal tumors in children and young adults: a clinicopathologic and molecular genetic study of 22 Korean cases

Studies on gastrointestinal stromal tumors (GISTs) in young patients are limited due to their rarity, and none have been conducted in Asian populations. GISTs from patients under the age of 30 were retrospectively reviewed and were analyzed for clinicopathologic features, immunohistochemistry for SDHB (succinate dehydrogenase subunit B), and mutations for exon 9, 11, 13, and 17 of KIT gene and exon 12, 14, and 18 of PDGFRA gene. We found two pediatric (<18 years old) and 20 young adult (18–30 years old) GIST cases.