Assessment of histologic disease activity in Crohn's disease: a systematic review.

BACKGROUND: Crohn's disease (CD) is an idiopathic, chronic, transmural inflammatory disorder of the gastrointestinal tract. Because mucosal involvement is near-universal, endoscopic healing has emerged as an important aspect in improving outcome. However, resolution of histologic disease activity has potential to convey additional benefit beyond that attained with endoscopic healing alone. Validated scoring systems of histologic disease activity are required to further assess this possibility. The aim of this study was to systematically review the existing histologic disease activity indices (HDAI) for CD and to assess their operating properties and potential use as outcome measures in clinical trials. METHODS: MEDLINE (Ovid), EMBASE (Ovid), PubMed, the Cochrane Library (CENTRAL), and Digestive Disease Week (DDW) abstracts were searched from 1981 to April 2013 for applicable studies to identify relevant studies for review and analysis. RESULTS: In total, 3732 citations were screened to obtain 89 articles for inclusion. Sixty-six HDAIs were characterized as either stepwise or numerical instruments. These HDAIs were used for either assessment of response to medical therapy or for comparison with biomarkers or imaging tests. None of the HDAIs identified was developed according to currently accepted methods for developing evaluative instruments, and none have been formally validated. CONCLUSIONS: Measurement of histologic disease activity has potential value in CD; however, no validated measures are available. Additional research is needed to develop a methodologically rigorous instrument for use in clinical investigation and potentially for clinical practice.

Reactive lymphoid hyperplasia of the terminal ileum: a benign (lymphoma-like) condition that may harbor aberrant immunohistochemical patterns or clonal immunoglobulin heavy chain gene rearrangements.

Small endoscopic biopsies of the terminal ileum may be difficult to assess for early involvement by lymphoma. Immunophenotypic and genotypic analyses are often utilized, but the performance of these studies in this setting is not well defined. Terminal ileal biopsies from 66 patients with prominent lymphoid hyperplasia and abnormal "lymphoma-like" morphology were evaluated by immunohistochemistry (IHC) for CD3, CD5, CD43, CD20, CD21, and CD10 expression and for IGH@ gene rearrangement by polymerase chain reaction using BIOMED-2 primers. Patients ranged in age from 3 to 80 years. Indications for endoscopy included inflammatory bowel disease (29), diarrhea and/or abdominal pain (28), history of lymphoma (13), and others (4). Four biopsies with abnormal morphology had abnormal IHC and a clonal IGH@ peak; all were obtained from patients with a history of lymphoma and determined to be recurrent lymphoma. Three biopsies with abnormal morphology and abnormal IHC but no clonal IGH@ peak were obtained from patients with a history of lymphoma (2) and chronic diarrhea (1); all showed symptom resolution or remission of disease (mean follow-up, 37 mo). Eight biopsies with abnormal morphology but no abnormal IHC expression also had abnormal IGH@ results (4 clonal and 4 borderline). IGH@ evaluation of follow-up biopsies for these cases were nonclonal (7) or clonal, but with a different clone from the prior biopsy (1); follow-up of the 8 patients showed no evidence of lymphoma (mean, 37.8 mo). Abnormal IHC expression pattern or clonal IGH@ rearrangement in endoscopic biopsies of the lymphoid-rich terminal ileum do not necessarily warrant a diagnosis of lymphoma. To prevent misdiagnosis, B-cell clonality studies should only be performed when there is strong clinical suspicion for lymphoma and compelling IHC data; the absence of a reproducible clone in repeat biopsy specimens may be useful in patients that do not have other clinical evidence of lymphoma.

HER2 expression in gastric and gastroesophageal junction adenocarcinoma in a US population: clinicopathologic analysis with proposed approach to HER2 assessment.

Recent evidence suggests that trastuzumab, a monoclonal antibody which targets HER2, in combination with chemotherapy is a therapeutic option in patients with HER2-positive gastric or gastroesophageal junction cancer. Widely accepted guidelines for HER2 testing in gastric and gastroesophageal junction cancer have not been established. The purpose of this study was to analyze the incidence and patterns of HER2 expression in gastric and gastroesophageal junction cancer using a tissue microarray approach, which closely simulates small biopsies routinely tested for HER2. One hundred sixty-nine patients, including 99 primary gastric adenocarcinomas and 70 primary gastroesophageal junction carcinomas were analyzed for HER2 overexpression by immunohistochemistry and HER2 gene amplification by fluorescence in situ hybridization using scoring schemes proposed by both American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) and the results of the recently published Trastuzumab for Gastric Cancer (ToGA) trial. In our analysis, 19 adenocarcinomas were HER2 positive, defined as either a HER2/CEP17 ratio >2.2 and/or a 3+ HER2 immunohistochemistry score with either the ASCO/CAP or ToGA scoring schemes. Of the 19 HER2-positive adenocarcinomas, 8 (42%) exhibited a characteristic strongly intense basolateral membranous staining pattern which would be interpreted as negative (1+) using the accepted ASCO/CAP scoring scheme for HER2 assessment in breast carcinoma, but were correctly labeled as 3+ positive using the proposed ToGA scoring scheme. Of the 19 HER2-positive adenocarcinomas, 8 (42%) demonstrated heterogeneous HER2 protein expression by immunohistochemistry. Twelve of 99 (12%) gastric carcinomas were positive for HER2. Of these, HER2 was more often identified in intestinal-type adenocarcinomas (10 of 52, 19%) compared with diffuse (2 of 34, 6%) adenocarcinoma. Seven of 70 (10%) gastroesophageal junction carcinomas were positive for HER2 of which all were intestinal type (7 of 58, 12%). HER2 status or primary tumor site did not correlate with patient survival. Gastric and gastroesophageal junction adenocarcinomas typically display a characteristic basolateral membranous pattern of HER2 expression which is often heterogeneous rendering routine evaluation of HER2 status on small tissue samples challenging.

Malignant pheochromocytoma presenting as incapacitating bony pain.

Among adrenal incidentalomas, pheochromocytomas are rare. Malignant pheochromocytoma is even less common, and it typically presents with classic hormonal symptoms, such as palpitations, labile blood pressures, and headaches. Bony metastasis usually occurs late in disease, but we report an unusual case of incapacitating bony pain as the initial presentation of malignant pheochromocytoma. Our patient is a 70-year-old woman with neurofibromatosis type 1 and a history of primary hyperparathyroidism, who tested negative for the ret mutation. She came to medical attention with chest pain and palpitations and was incidentally found to have an adrenal mass. Serum and urine testing was consistent with pheochromocytoma. Her blood pressure was easily controlled as she awaited elective adrenalectomy; however, she quickly developed severe, diffuse bony pain. She represented with hypercalcemia, spontaneous fractures, and incapacitating pain that required such high doses of pain medications that she had to be intubated. Further imaging and bone marrow biopsy confirmed metastatic neuroendocrine tumor. She received one round of chemotherapy with no change in her bony pain, which was her primary complaint. Unfortunately, her treatment options were limited by the heavy sedation required for comfort, and in the end, it was her bony pain rather than hormonal symptoms that made her disease untreatable.

Histologic and molecular analyses of colonic perineurial-like proliferations in serrated polyps: perineurial-like stromal proliferations are seen in sessile serrated adenomas.

Colonic perineuriomas are recently described benign mucosal polyps that are composed of a bland spindle cell proliferation surrounding crypts that often demonstrate hyperplastic/serrated epithelial changes. However, the origin of this unique stromal proliferation is still unclear, and the association with serrated polyps, including sessile serrated adenomas, has not been fully described. We evaluated the pathologic and molecular features of colonic polyps associated with perineurial-like proliferations in 2 retrospective cohorts: (1) a series of 198 consecutive sessile serrated adenomas and (2) 20 colonic polyps diagnosed as a perineurioma irrespective of the presence of serrated colonic crypts. Thirteen of 198 (6.5%) sessile serrated adenomas demonstrated a perineurial-like stromal proliferation, with most (12 of 13, 92%) involving the right (9 cases) and transverse colon (3 cases). In all 13 cases, the perineurial-like proliferation surrounded serrated colonic crypts and typically involved only a small area of the sessile serrated adenoma (average 9% of polyp size; range, 2% to 19%). All 11 polyps evaluated for epithelial membrane antigen (EMA) expression demonstrated stromal EMA staining limited to the perineurial-like proliferation. Twelve of 13 (92%) sessile serrated adenomas with perineurial-like proliferations demonstrated a pV600E BRAF mutation. Of the 20 colonic polyps diagnosed as a perineurioma, 18 (90%) demonstrated serrated crypts intimately associated with the perineurial-like proliferation. In 13 of 18 polyps with associated serrated crypts, all serrated crypts were invested with the perineurial proliferation. In 5 cases, serrated crypts were seen away from the perineurial proliferation. Of these 18 polyps, the majority (16 of 18, 89%) were microvesicular hyperplastic polyps involving the left colon. However, 2 (11%) polyps in the right colon demonstrated histologic features diagnostic of sessile serrated adenoma. All 18 polyps with serrated crypts demonstrated a pV600E BRAF mutation. In contrast, the 2 polyps not associated with serrated crypts were negative for a BRAF mutation. Our results show for the first time that perineurial-like stromal proliferations frequently occur in sessile serrated adenomas. The presence of focal perineurial-like stromal proliferations in sessile serrated adenomas and the common finding of serrated crypts in colonic perineuriomas are likely indicative of an epithelial-stromal interaction, possibly related to some factor elaborated by the serrated epithelium.

A two-antibody mismatch repair protein immunohistochemistry screening approach for colorectal carcinomas, skin sebaceous tumors, and gynecologic tract carcinomas.

Mismatch repair protein immunohistochemistry is a widely used method for detecting patients at risk for Lynch syndrome. Recent data suggest that a two-antibody panel approach using PMS2 and MSH6 is an effective screening protocol for colorectal carcinoma, but there are limited data concerning this approach for extraintestinal tumors. The purpose of this study was to review the utility of a two-antibody panel approach in colorectal carcinoma and extraintestinal tumors. We evaluated mismatch repair protein expression in two cohorts: (1) a retrospective analysis of intestinal and extraintestinal tumors (n=334) tested for mismatch repair protein immunohistochemistry and (2) a prospectively accrued series of intestinal, gynecologic tract, and skin sebaceous neoplasms (n=98). A total of 432 cases were analyzed, including 323 colorectal, 50 gynecologic tract, 49 skin sebaceous, and 10 other neoplasms. Overall, 102/432 tumors (24%) demonstrated loss of at least one mismatch repair protein. Concurrent loss of MLH1 and PMS2 was the most common pattern of abnormal expression (50/432, 12%) followed by concurrent loss of MSH2 and MSH6 (33/432, 8%). Of 55 cases with abnormal PMS2 expression, 5 (9%) demonstrated isolated loss of PMS2 expression. Of 47 cases with abnormal MSH6 expression, 14 (30%) demonstrated isolated loss of MSH6 expression. Isolated loss of MLH1 or MSH2 was not observed. Colorectal carcinomas more frequently demonstrated abnormal expression of PMS2 (39/59, 66%). Skin sebaceous neoplasms more frequently demonstrated abnormal expression of MSH6 (18/24, 75%, respectively). A total of 65 tumors with abnormal mismatch repair protein expression were tested for microsatellite instability (MSI): 47 (72%) MSI high, 9 (14%) MSI low, and 9 (14%) microsatellite stable (MSS). Abnormal MSH6 expression accounted for 14/18 (78%) cases that were MSS or MSI low. Our findings confirm the utility of a two-antibody approach using PMS2 and MSH6 in colorectal carcinoma and indicate that this approach is effective in extraintestinal neoplasms associated with Lynch syndrome.