Dysplasia in Barrett esophagus has been recognized to be morphologically heterogenous, featuring adenomatous, foveolar, and hybrid phenotypes. Recent studies have suggested a tumor suppressor role for CDX-2 in the metaplasia-dysplasia-carcinoma sequence. The phenotypic stability and role of CDX-2 in the neoplastic progression of different types of dysplasias have not been evaluated. Thirty-eight endoscopic mucosal resections with dysplasia and/or intramucosal carcinoma (IMC) arising in Barrett esophagus were evaluated for the expression of MUC5AC, MUC6, MUC2, CD10, and CDX-2. The background mucosa was also evaluated. The results were correlated with morphologic classification and clinicopathologic parameters. Of 38 endoscopic mucosal resections, 23 had IMC and dysplasia, 8 had IMC only, and 7 had dysplasia only. Among dysplastic lesions, 73% were foveolar, 17% were adenomatous, and 10% were hybrid. Twenty of 23 cases with dysplasia and adjacent IMC showed an identical immunophenotype of dysplasia and IMC comprising 16 gastric, 3 intestinal, and 1 mixed immunophenotype. Three cases showed discordance of dysplasia and IMC immunophenotype. These findings suggest that most Barrett-related IMC cases are either gastric or intestinal, with phenotypic stability during progression supporting separate gastric and intestinal pathways of carcinogenesis. CDX-2 showed gradual downregulation of expression during progression in adenomatous dysplasia but not in foveolar or hybrid dysplasia, supporting a tumor suppressor role, at least in the intestinal pathway. CDX-2 was also found to be expressed to a greater degree in intestinal metaplasia compared with nonintestinalized columnar metaplasia. Consistent with CDX-2 as a tumor suppressor, this suggests that nonintestinalized columnar metaplasia may be an unstable intermediate state at risk for neoplastic progression.

The advent of totally internal ureteric stents has the potential to reduce hospital stay in paediatric pyeloplasty. Traditionally, discharge from hospital has followed removal of an external trans-anastomotic drain, usually 5 days to a week post-operatively. The use of totally internal catheters negates the need for nursing supervision by removing external attachments that a paediatric patient might inadvertently dislodge. The length of hospital stay for pyeloplasty using a Double-J ureteric stent was compared with our previous method of trans-anastomotic feeding tube nephrostomy drainage. The results show the use of Double-J stenting to be advantageous in paediatric pyeloplasty by decreasing considerably the length of hospital stay. This is clearly of benefit to the patient, who returns to the family setting much earlier. Despite the need for an outpatient endoscopic procedure to remove the stent, savings in treatment costs and improved efficiency of bed use are also achieved.

Pancreatic acinar cystadenomas (ACAs) are rare cystic lesions showing acinar differentiation with benign outcome. Although debated, ACAs are favored to be neoplastic and potentially the benign counterpart of acinar cystadenocarcinoma. We present the largest single institution series to date comprising 10 cases. The mean age was 49 years with a female predominance (M:F=1:2.3). Abdominal/flank pain was the most common presentation (n=6). Serum amylase/lipase and cyst fluid amylase were often elevated. All lesions had a benign outcome on follow-up (5 to 67 mo). The lesions were unilocular (n=3) or multilocular (n=7) with mean size of 3.8 cm (range, 2.9 to 5.0 cm) and 5.1 cm (range, 2.0 to 7.5 cm), respectively. Eight lesions were unifocal with locations as follows: head (n=2), head/neck (n=2), body (n=1), tail (n=1), predominantly extrapancreatic with a microscopic intrapancreatic component (n=1), and unspecified location (n=1). Two lesions were multifocal, involving the head/uncinate/body and pancreatic head, respectively. Two aspects of ACAs that may represent a diagnostic pitfall include the propensity for acinar epithelium to appear as nondescript flat/cuboidal epithelium (trypsin/chymotrypsin immunopositive) and epithelial heterogeneity, with focal mucinous and squamous epithelium, the latter particularly in multilocular variants. In addition, 2 cases with intracystic nodules were observed. Array comparative genomic hybridization performed on 1 of these cases showed multiple chromosomal gains involving 1p, 3p, 5q, 6p, 7q, 8, 10q, 11, 14, 20, and X. These findings provide preliminary evidence that ACAs represent a cystic neoplastic lesion.

Patients with Crohn's disease who develop an adenoma-like DALM, regardless of its location in relationship to previous or concurrent colitis, may be treated safely with polypectomy and continued surveillance.

ature (Fig. 2). A bone scan was negative and he underCase report went radical cystoprostatectomy with ileal conduit diversion. Histology of the tumour confirmed metastatic A 51-year-old man presented with haematuria; radiological investigation revealed a large left renal mass but there RCC, extensively infiltrating the perivesical tissue and prostate. The patient died from the disease 4 months later. was no evidence of metastases. He underwent radical nephrectomy and histological analysis confirmed a 6 cm RCC ( Fig. 1) with tumour within the renal vein. He made Comment an uneventful recovery but 6 months later re-presented with frank haematuria. Cystoscopy revealed a tumour Renal tumours are well known for their propensity to metastasize but isolated metastatic RCC to the bladder is involving the left lateral aspect of the bladder and bimanual examination detected a mass. Resection biopsies revealed metastatic RCC invading the bladder muscul- 650

We systematically evaluated the clinicopathologic features and outcome of a rare, unusual variant of ischemic colitis that presents as a mass lesion mimicking malignancy on imaging or colonoscopy. A retrospective search was performed for cases with a histologic diagnosis of ischemic colitis and a clinical impression of malignancy. Of the 23 patients initially identified, 4 were excluded because clinical and histologic review showed mucosal prolapse (n=1), discrete colon polyp (n=2), and a diverticular mass (n=1) without concern for malignancy. The mass-forming variant of ischemic colitis (n=19) was seen predominantly in elderly (mean age 71.8 y) women (63.2%) with a striking predilection for the right colon (13/19), particularly the cecum (n=6). Abdominal pain (52.6%) and hematochezia (26.3%) were the most common presenting symptoms. A computed tomography scan showed segmental thickening suspicious for malignancy in 6/8 patients. Colonoscopy revealed an exophytic (n=16) or stricturing (n=3) mass with a mean size of 4.67 cm. Mucosal biopsies showed features typical for ischemic colitis in all cases. A colectomy was performed in 4 cases. In 2, the mass-like appearance was due to marked submucosal and mural edema, whereas in the other 2 cases, with a malignant stricture-like lesion, marked submucosal fibrosis and cholesterol emboli were present. No malignancy was identified on follow-up in any patient (mean 39.9 mo). Follow-up colonoscopy was performed in 7 patients 1 to 32 weeks after initial presentation and showed resolution of the mass in all cases. Awareness of this rare variant of ischemic colitis will prevent unnecessary resections in these patients.

The interpretation of colonic biopsies related to inflammatory conditions can be challenging because the colorectal mucosa has a limited repertoire of morphologic responses to various injurious agents. Only few processes have specific diagnostic features, and many of the various histological patterns reflect severity and duration of the disease. Importantly the correlation with endoscopic and clinical information is often cardinal to arrive at a specific diagnosis in many cases.

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