Lymphocytic and collagenous colitis: an overview of so-called microscopic colitis

The entity of 'microscopic colitis' is being diagnosed with increasing frequency and is a well-established clinicopathological diagnosis that is underpinned by a triad of watery diarrhea, normal results on endoscopy and characteristic microscopic findings. Careful histopathological evaluation and awareness of its numerous associations (especially with drugs and celiac disease) and mimics will lead to the correct diagnosis of microscopic colitis. The etiology of microscopic colitis remains enigmatic and is multifactorial with different elements being more influential in different individuals. Treatment includes antidiarrheal agents and anti-inflammatory drugs (including steroids). The purpose of this article is to provide some clarity on nomenclature, discuss the multitude of conditions that can occur synchronously or metachronously with microscopic colitis and their role in the etiopathogenesis of this condition, provide a detailed review of the pathological aspects of the disease and to briefly discuss treatment trends.

A multi-centre pathologist survey on pathological processing and regression grading of colorectal cancer resection specimens treated by neoadjuvant chemoradiation

To ascertain the approach and degree of consensus of pathologists in the handling and regression grading of colorectal cancer resection specimens treated with neoadjuvant chemoradiation, a ten-part questionnaire was circulated to 18 gastrointestinal pathologists in eight countries. The questions were specific and addressed pertinent issues related to colorectal cancer with neoadjuvant chemoradiation. There is a lack of consensus on how to handle the specimen, number of sections taken, correlation with pre- and post-operative radiological imaging, and especially, regression grading schema employed. Consensus in the form of guidelines is required so that the pathological assessment of these specimens will provide clinically relevant information for patient management, irrespective of location.

Lymphoepithelioma-like carcinoma of the colon

An 85-year old female had a polypoid tumour in the sigmoid colon that histologically conformed to a lymphoepithelioma-like (LEL) carcinoma. The tumour was arranged in cords, chains, clusters and microalveoli of pleomorphic, irregular cells set within a dense intratumoral lymphocytic stroma. The tumour was EBV-negative and showed loss of MLH-1 and PMS-2 mismatch repair proteins. The patient did not fulfil the criteria for HNPCC. Only 5 other cases of primary colonic LEL carcinoma have been described previously and only one case appears to have an unequivocal association with EBV. In addition, one of the cases was encountered in a HNPCC patient. This is an unusual morphologic variant of a microsatellite unstable tumour with a LEL pattern, not associated with EBV.

Collision tumor of the stomach: an unusual combination of adenocarcinoma and immature "neuroepitheliomatous" teratoma

A 54-year-old woman was diagnosed with an asymptomatic gastric tumor during routine radiological investigation for staging of breast carcinoma. Subsequent endoscopic biopsy confirmed a poorly differentiated adenocarcinoma. Surgical resection of the stomach showed a tumor with 2 distinct components: a superficial lymphoepithelioma-like adenocarcinoma and a deeper submucosal component consistent with immature teratoma. There was lymph node metastasis. The patient is well without any evidence of disease 18 months post surgery.

Selected unusual tumors of the stomach: a review

Several unusual stomach tumors have been recently described. In addition, some tumors that are often encountered in other sites may rarely occur as primary gastric tumors. The diagnostic surgical pathologist needs to be aware of some of these lesions to prevent misdiagnosis. This overview discusses the key clinical features, pathology, immunohistochemistry, and relevant molecular findings of multiple minute gastrointestinal stromal tumors and interstitial cell of Cajal hyperplasia, nerve sheath tumors (schwannoma and perineurioma), gastroblastoma, granular cell tumor, glomus tumor, plexiform angiomyxoid myofibroblastic tumor, and primary clear cell sarcoma of the gastrointestinal tract that occur as primary gastric neoplasms.

The prognostic value of grade of regression and oncocytic change in rectal adenocarcinoma treated with neo-adjuvant chemoradiotherapy

BACKGROUND

Pathological staging and regression grading may affect the clinical outcome in rectal carcinoma patients treated with neoadjuvant chemoradiation (NACRT). Oncocytic change (OC) has also been described in the residual tumor. This study assesses the correlation of degree of pathological response and OC with clinical outcome.

METHODS

Seventy-five cases of rectal adenocarcinoma undergoing NACRT followed by surgery were retrospectively analyzed for preoperative and post-operative staging, degree of tumor response to NACRT using the Dworak Regression score (DR) and Tumor Regression Grading (TRG) systems, as well as the proportion of cells showing OC. These parameters were correlated with overall survival (OS) and disease-free survival (DFS).

RESULTS

Significant correlation was found between post-operative T and N stage and OS (P = 0.005 and 0.002, respectively); and post-operative and preoperative T stage with DFS (P = 0.002 and 0.02, respectively). Grouping patients by TRG scores (TRG1-3 vs TRG4-5) also proved to be a significant independent prognosticator for DFS (P < 0.001). The DR score groups and OC (<35% vs. >35%) were not statistically significant predictors of clinical outcome.

CONCLUSIONS

Post-NACRT T and N staging and the TRG system are important prognostic indicators. The presence and extent of OC needs to be better understood and further investigated.

Follicular patterned lesions of the thyroid gland: a practical algorithmic approach

Follicular patterned lesions of the thyroid are problematic and interpretation is often subjective. While thyroid experts are comfortable with their own criteria and thresholds, those encountering these lesions sporadically have a degree of uncertainty with a proportion of cases. The purpose of this review is to highlight the importance of proper diligent sampling of an encapsulated thyroid lesion (in totality in many cases), examination for capsular and vascular invasion, and finally the assessment of nuclear changes that are pathognomonic of papillary thyroid carcinoma (PTC). Based on these established criteria, an algorithmic approach is suggested using known, accepted terminology. The importance of unequivocal, clear-cut nuclear features of PTC as opposed to inconclusive features is stressed. If the nuclear features in an encapsulated, non-invasive follicular patterned lesion fall short of those encountered in classical PTC, but nonetheless are still worrying or concerning, the term 'uncertain malignant potential or behaviour, most likely benign' is suggested. Indubitable, classical PTC nuclei (whether diffuse or restricted to a single high-power field) are diagnostic of a PTC be it classical, non-invasive or invasive follicular variant PTC. Capsular and vascular invasion remain the only reliable predictors of outcome, as non-invasive, encapsulated follicular variant PTC, even with diffuse PTC nuclear change, behaves in an indolent fashion.

A descriptive analysis of gastric cancer specimen processing techniques

BACKGROUND

Adherence to guidelines for adequate gastric cancer specimen assessment is poor in North America. Inadequate staging and poor prognosis were noted in some series when these guidelines are not met. Recent advances have been made in standardizing cancer pathology reports in Canada; however, the uptake of these reporting systems is unknown for gastric cancer. A survey of pathologists in Ontario was performed to outline the processing techniques and practices for assessing gastric cancer specimens.

METHODS

A survey was designed through a collaboration of surgical oncologists, general surgeons, pathologists, and research staff. Pathologists were identified using the College of Physicians and Surgeons of Ontario and MD Select databases. Participants were surveyed online or by mail-out.

RESULTS

The response rate was 40.2% (147/366). Vascular invasion, perineural invasion, and signet ring cells were all reported as being examined for by the majority of pathologists. Fat clearing solution and keratin immunohistochemical techniques were not reported as being consistently utilized. Less than 70% of pathologists indicated using a form of synoptic report.

CONCLUSION

Variations in practice and technique were observed. This may or may not reflect differences in quality of care or simply preferences for achieving equivalent results in the absence of standardized procedures. Education, evidence-based procedural guidelines and further research are required to provide infrastructure and support for pathologists and surgeons involved in the care of gastric cancer patients.

A study to investigate the role of p27 and cyclin E immunoexpression as a prognostic factor in early breast carcinoma

Background

Cyclin E and p27 expression is easy to assess in human tissues by standard immunohistochemical techniques. Immunohistochemistry is cost effective, relatively easy to perform and will play more of a role in the future management of cancer. The aim of this study was to investigate the role of p27 and cyclin E immunoexpression as a prognostic factor in early breast carcinoma.

Methods

Cyclin E and p27 immunohistochemistry was performed on sixty six cases of breast carcinoma submitted over a five year period to the Division of Anatomical Pathology, Groote Schuur hospital; Whittaker and Associates; and PathCare. All tumours included in this study were less than 5 cm in diameter (pT1 and pT2 stage) and all the patients had wide local excisions performed. Follow up information was obtained from patient folders in the Department of Radiation Oncology.

Results

There was no significant association of cyclin E and p27 expression with distant metastasis free survival (MFS) for all invasive carcinomas in contrast to grade, lymph node spread and vascular invasion. However, there was a statistically significant direct association of cyclin E with distant metastases in all invasive carcinomas, in the subgroup of infiltrating duct carcinomas (IDC) and in the node negative group when cyclin E was stratified as negative and positive (low/high). In this study of early breast carcinoma, only 9/66 cases showed cyclin E expression. Of these, four patients had distant metastases, one patient had a local recurrence and four patients were alive at last follow-up. Furthermore, cyclin E expression was significantly associated with grade, lymph node spread, oestrogen receptor status and histological type. None of the lobular carcinomas showed cyclin E positivity and only one case of lobular carcinoma presented with distant metastases.

59/66 cases were positive (low/high) for p27 while seven cases were negative, 22 cases showed low expression and 37 cases demonstrated high p27 expression.

p27 was significantly associated with oestrogen receptor status only for all invasive carcinomas and in the IDC group. There was no statistical relationship between p27 and cyclin E, but 50 (76%) tumours with positive p27 expression were negative for cyclin E. There were similar results for the invasive ductal carcinoma subgroup.

Conclusion

This study shows that p27 and cyclin E are not good independent prognostic markers for early breast carcinoma in contrast to grade, lymph node spread and vascular invasion for all invasive carcinomas. However, cyclin E provides some prognostic value as there is a direct statistical association with the development of distant metastases. Many previous studies have correlated overexpression of cyclin E with an aggressive course. The inverse relationship between p27 and cyclin E expression which has been reported in the literature has been highlighted, but this was not statistically significant. Most cases showed positive p27 expression and negative Cyclin E expression. This may be due to the early stage of the disease.

Familial paraganglioma syndromes

Paragangliomas and phaeochromocytomas may occur in syndromic or sporadic forms. The former are well recognised with multiple endocrine neoplasia (MEN) type 2 and von Hippel-Lindau syndromes. A few cases are associated with neurofibromatosis type 1. The familial paraganglioma-phaeochromocytoma syndromes are less well recognised, but as more genetic testing is performed, more cases belonging to this syndrome will be revealed. These syndromes result from mutations in one of three subunits of the succinate dehydrogenase (SDH) gene. There are four types: type 1 associated with SDHD, type 2 with an unknown gene, type 3 with SDHC and type 4 with SDHB. There are distinct genotypic-phenotypic correlations with each mutation. Patients with SDHB mutations have a positive family history in 33% of cases, present with single tumours around 30 years of age and have extra-adrenal paragangliomas mainly in the abdomen and pelvis; 20% may also have phaeochromocytomas, and tumours in these patients have a great propensity to metastasise. Patients with SDHD and SDHC mutations have a higher positive family history (66%) and have head and neck paragangliomas. SDHD patients present at 30 years with multiple tumours, while in SDHC mutation carriers, single tumours appear at around 38 years of age. A small percentage of patients with sporadic paragangliomas/phaeochromocytomas may have SDH mutations as well.

Gangliocytic paraganglioma: a rare case with metastases of all 3 elements to liver and lymph nodes

Gangliocytic paragangliomas are a rare but well-described neuroendocrine tumor with a proclivity for the duodenal area. It is usually a locally infiltrative lesion with a good prognosis. Rare cases that spread to lymph nodes have been documented. A 52-year-old female was found to have a duodenal tumor, enlarged regional lymph nodes, and multiple small nodules in the liver. The duodenal tumor was a classic triphasic gangliocytic paraganglioma. Two regional lymph nodes and one of the nodules in the liver were noted to contain all 3 elements constituting a gangliocytic paraganglioma. This is the second case of gangliocytic paraganglioma with liver spread and is also noteworthy because of the presence of all 3 elements in the metastases. The presence of lymph node and liver metastases should not result in overtreatment as such behavior is not necessarily fraught with a bad clinical outcome. It is probably best to regard such cases as having "uncertain malignant potential" and advocate careful follow-up.