Petris, Giovanni De

Abstract Context. —The pathologist plays the leading role in distinguishing pseudoneoplasms from truly neoplastic lesions in the gastrointestinal tract. Objective. —This review was conducted to heighten awareness of pseudoneoplasms, to help differentiate among the various types of pseudoneoplasms, and to help distinguish pseudoneoplasms from malignancies. Data Sources. —This review is based on the medical literature on pseudoneoplasms in MEDLINE and the authors' own experiences. Reference lists of retrieved articles were also reviewed to identify additional articles. Conclusions. —A classification of pseudoneoplasms, according to the mechanism of injury to the gastrointestinal tract, morphologic patterns, and heterotopia, may be useful in providing a diagnostic framework in which ancillary techniques often have a diagnostic role. Several pseudoneoplasms may be closely associated with true neoplasms (eg, malakoplakia, prolapsetype lesions) because of the nonspecific nature of the response of the intestine to injury.

Abstract Context. —Establishing adequate interobserver agreement is crucial not only for standardization of patient care but also to ensure validity of findings in multi-institutional trials. Objective. —To evaluate interobserver agreement in assessing chronic hepatitis C (HCV) and acute cellular rejection (ACR) among 17 hepatopathologists involved in the “Hepatitis C 3” trial. Design. —The trial is a randomized multicenter (17 institutions) study involving 312 patients undergoing transplantation for HCV. Patients are randomized to 3 treatment arms. For final data analysis, all biopsy specimens are reviewed by a central pathologist (G.J.N.). Recurrence of HCV is evaluated according to the Batts and Ludwig schema. The 1997 Banff schema is used to evaluate ACR. To assess interobserver agreement, hematoxylin-eosin–stained sections from 11 liver biopsy specimens (6 HCV and 5 ACR) were sent by the central pathologist to 16 local pathologists from 13 institutions. Statistical analysis was performed on raw ACR/HCV data as well as data grouped according to clinically significant primary endpoint cutoffs. Results. —Statistically significant agreement was found among all participating pathologists ( P < .001). On κ analysis, the degree of agreement was rated “moderate” for HCV grade and stage and ACR global grading (κ = 0.30, 0.33, and 0.37, respectively). Interobserver agreement was weaker for rejection activity index scoring of ACR (κ = 0.15). A stronger degree of agreement was found when scores were grouped based on endpoint cutoffs (κ = 0.76 “almost perfect” for HCV and 0.62 “substantial” for ACR). Conclusions. —An overall statistically significant interobserver agreement was found among 17 pathologists using the 1997 Banff schema and the Batts and Ludwig schema.

Microscopic colitis (MC) is an umbrella term that encompasses lymphocytic colitis (LC) and collagenous colitis (CC). Several histological variants of these 2 entities exist; among them is the uncommon giant cell colitis (GCC), in which histiocytic giant cells (GCs) are present in background of CC or LC. We report the case of a 71-year-old woman complaining of watery diarrhea for several years that was diagnosed with CC. At follow-up, she developed giant cell colitis (GCC). Nine years later, a colectomy revealed a form of microscopic colitis in which significant intraepithelial lymphocytosis and collagen plate thickening have disappeared while GCs persisted with diffuse mononuclear cells inflammation of the lamina propria. Thinning of the collagen plate in association with GCs has been described previously. The case contributes the possibility of further evolution of MC into a pure giant cell colitis in which the prototypical manifestations of MC have all but disappeared.

Common variable immunodeficiency (CVID) is associated with an increased risk of gastric cancer. The aim of the study was to determine the morphological features of CVID-associated gastric adenocarcinoma (CAGA) and of the background gastritis. The population of gastric cancer patients with CVID of Mayo Clinic in the period 2000-2010 was studied; 6 cases of CVID (2 males, 4 females, average age 47 years, age range 26-71 years) were found in 5793 patients with gastric cancer in the study period. Each patient underwent gastric resection for which histology slides were reviewed. Chronic gastritis variables, CVID-related findings, and features of the adenocarcinoma were recorded. CAGA was of intestinal type, with high number of intratumoral lymphocytes (ITLs). Cancer was diagnosed in younger patients than in the overall population of gastric cancer. Severe atrophic metaplastic pangastritis with extensive dysplasia was present in the background in 4 cases, with features of lymphocytic gastritis in 2 cases. Features of CVID (plasma cells paucity in 4 of 6 cases, lymphoid nodules prominent in four cases) could be detected. In summary, gastric adenocarcinoma at young age with ITLs, accompanied by atrophic metaplastic pangastritis, should alert the pathologist of the possibility of CAGA. It follows that, in presence of those characteristics, the search of CVID-associated abnormalities should be undertaken in the nonneoplastic tissues.

Abstract With a 5-year survival rate of &lt;5%, pancreatic cancer is one of the most rapidly fatal malignancies. Current protocols for the treatment of pancreas cancer are not as effective as we desire. In this study, we show that a novel Mucin-1 (MUC1)-based vaccine in combination with a cyclooxygenase-2 inhibitor (celecoxib), and low-dose chemotherapy (gemcitabine) was effective in preventing the progression of preneoplastic intraepithelial lesions to invasive pancreatic ductal adenocarcinomas. The study was conducted in an appropriate triple transgenic model of spontaneous pancreatic cancer induced by the KRASG12D mutation and that expresses human MUC1 as a self molecule. The combination treatment elicited robust antitumor cellular and humoral immune responses and was associated with increased apoptosis in the tumor. The mechanism for the increased immune response was attributed to the down-regulation of circulating prostaglandin E2 and indoleamine 2, 3,-dioxygenase enzymatic activity, as well as decreased levels of T regulatory and myeloid suppressor cells within the tumor microenvironment. The preclinical data provide the rationale to design clinical trials with a combination of MUC1-based vaccine, celecoxib, and gemcitabine for the treatment of pancreatic cancer.

In keeping with the stated goal of providing the surgical pathologist with tools to recognize abnormalities of the gastrointestinal (GI) tract due to drugs (AGIDS), in part II of this review we embark in a more organ-based description of AGIDS. Adequate space is given to the numerous adverse gastrointestinal effects of nonsteroidal anti-inflammatory drugs. Pill esophagitis, esophagitis dissecans, proton pump inhibitors’ effects, diaphragm disease, and the recently described effects of drugs such as olmesartan, mycophenolate, and of compounds such as yttrium-90 are highlighted among several others. The inclusion of drug effects in the differential diagnosis of “conventional” diseases (such as gastric antral vascular ectasia, graft-versus-host disease, ischemic colitis, acute colitis, collagenous enteritis, inflammatory bowel disease) is underscored to avoid sometimes significant diagnostic pitfalls. We reiterate the message of the necessary collaboration between pathologist and clinician in the recognition of these entities to provide the best patient care.

Abnormalities of the gastrointestinal (GI) tract due to drugs (AGIDs) are numerous and have significant impact. The aim of this narrative review is to help the practicing surgical pathologist recognize selected AGIDs. The adverse drug effects presented were chosen with an emphasis on recent and significant pathological and clinical contributions. The selection was based on a thorough review of the PUBMED-based literature and on the authors’ opinions and experience. In the first part of the review, diagnostic abnormalities due to crystals (eg, iron, biphosphonates, nonsystemic drugs), mitosis arresting drugs (colchicine, taxanes), and biological agents, especially ipilimumab, are discussed. Some AGIDs’ histopathologic features can be easily recognized. It is however the clinical correlation that in many cases of AGIDs will provide the necessary support for a drug effect diagnosis. The identification of AGIDs requires heightened awareness of the medical team in which close collaboration of pathologists and clinicians cannot be overemphasized.

Inflammatory cap polyposis (ICP) is a rare nonneoplastic polyposis of the colon of unknown etiology that can be confused with prolapse-induced polyps and hyperplastic polyposis. We contribute a case of ICP from a 59-year-old woman who was affected by severe constipation and hematochezia. Numerous sessile and semipedunculated polyps were found in the colon, all with cap of whitish fibrin. Histology revealed erosion of the surface, superficial dilated crypts filled with mucoid inflammatory exudate, and minimal crypt serration, all findings typical of ICP. Only the largest polyps had smooth muscle in the mucosa. Ki-67 showed modest expansion and irregular distribution of the crypts proliferative areas. Low-degree positivity for p16, similar to that of hyperplastic polyps, was found. CK20 was expressed as in normal mucosa. Distinguishing between ICP and other polyposis is important because of difference in management.