Current diagnostic pathology最新文献

The classification of endometrial hyperplasias and neoplasms often causes diagnostic problems. This review aims to provide a broad overview of the terminology and microscopic features of endometrial hyperplasias, emphasizes the morphological features that are useful in categorizing these and in discriminating them from endometrial carcinoma. It also provides a brief summary of the variants of endometrial carcinoma. A more detailed discussion of endometrial hyperplasias and neoplasms can be found elsewhere.

Gliomas are the most common primary neoplasms of the brain. They are a heterogeneous group of tumours characterized by infiltrative growth, and relative resistance to radiotherapy and chemotherapy. Glioblastomas have complex chromosomal aberrations including amplifications and gains of 7p, 12q13–q21, and chromosome 19, and losses are 10q, 9p, 13q and 22q, whereas the karyotypes of pilocytic astrocytomas show only limited changes. Important genetic aberrations include up-regulation of EGFR and MDM2 function and loss of PTEN function in primary glioblastoma, and up-regulation of PDGFRA and CDK4 function in secondary glioblastomas that arise from a pre-existing lower grade astrocytoma. TP53, CDKNA2 and RB1 functions are often lost in secondary glioblastomas. Amplifications of PDGFRA, KIT and VEGFR2 may also have a role in the genesis of some gliomas. The proteins encoded by these genes have become targets for novel therapies, which include specific inhibitors of the EGFR, KIT, and PDGFR receptor tyrosine kinases.

Squamous cell carcinoma (SCC) is the most common malignant lesion of the vulva, the incidence of which appears to be increasing. Squamous vulval intraepithelial neoplasia (VIN) is the recognized precursor lesion. The vulva, being composed of skin, is also subject to a range of dermatological conditions that may mimic dysplasia. This symposium seeks to identify and address the major areas of difficulty faced by pathologists in diagnosing these pre-invasive and invasive squamous epithelial lesions of the vulva.

The diagnosis of borderline ovarian tumours is problematic. Traditionally, the absence of stromal invasion has distinguished borderline ovarian tumours from their malignant counterparts. The recent recognition of microinvasion associated with borderline neoplasms, the analysis of peritoneal implants (PIs), and issues associated with tumour nomenclature contribute to this diagnositc challenge. Furthermore, a proposed reclassification of serous ovarian tumours abandoning the borderline category in favour of atypical proliferative serous tumour (APST) and micropapillary serous carcinoma (MPSC); the latter being subdivided into invasive (invasive MPSC or low-grade serous carcinoma) and non-invasive (non-invasive MPSC or intraepithelial low-grade serous carcinoma) variants, has resulted in the inconsistent use of tumour nomenclature. To facilitate understanding, both the old and new terminologies of serous tumours will be used in this review. Unfortunately, diagnostic dilemmas are not restricted to serous ovarian tumours, in mucinous ovarian tumours, benign, borderline and malignant epithelium can co-exist in the same lesion and metastatic mucinous carcinoma from the gastrointestinal tract can mimic a primary mucinous ovarian tumour. Pseudomyxoma peritonei, which was originally considered as the peritoneal lesion (or implant) associated with a borderline mucinous ovarian tumour, is now believed to be secondary to a low-grade primary mucinous tumour of the appendix. Finally, accurate and complete histological assessment requires the pathologist to be aware of newly described lesions e.g. the seromucinous tumours. In this article, the difficulties associated with the histological diagnosis of the above tumours will be considered with emphasis on the identification of early invasion.

Cervical carcinomas usually arise from dysplastic epithelium. Squamous cell carcinoma, the most common type, evolves from cervical intraepithelial neoplasia (CIN) while adenocarcinoma develops from cervical glandular intraepithelial neoplasia (CGIN). The diagnosis of frankly invasive disease does not create a diagnostic problem. In contrast, confident diagnosis of the earliest stage of invasive disease arising from a dysplastic precursor lesion is problematic. The diagnostic process is further complicated by a lack of concordance concerning the nature (and behaviour) of certain diseases associated with the cervix e.g. CIN3-like squamous carcinoma, papillary squamo-transitional cell carcinoma, minimal deviation adenocarcinoma, adenoid basal carcinoma and microcystic adenocarcinoma. In this mini-symposium, an attempt has been made to clarify the features that are suggestive of definitive stromal invasion and to highlight the features of those unusual carcinomas that are often misinterpreted as non-invasive disease.

The epithelial cells of the intestinal crypts enable the gut to perform its physiological functions. The intestinal stem cell is responsible for maintaining the epithelial cell population of the crypts. Little is known of the stem cells in terms of their identity, numbers and locations within the crypts. The accumulation of genetic mutations within stem cells and the subsequent spread of these mutated clones of cells leads to the growth of adenomas. This article will focus on the maintenance of the cell population of the intestinal crypts by the intestinal stem cell, and will consider the evidence relating to stem cell identity, location and function, the molecular regulation of stem cell function and the development and growth of epithelial tumours within the gastrointestinal tract.

Immunocytochemistry as an investigative tool in the field of histopathology has evolved into the most widespread, diagnostically useful technique in the assessment of disease states. Although as a procedure it has been employed for over 50 years, the most significant innovative advances have occurred over the past 10–15 years, with the advent of heat-mediated antigen-retrieval methodologies, improved antigen-detection systems, signal-amplification procedures, double labelling and the development of semi- and fully automated immunostaining machines. All of these developments have found a niche within the field of dermatopathology at both the light and electron microscope levels. Optimizing the amount of useful information possible from any given sample should be the ideal goal.

The differential diagnosis of chronic inflammatory bowel disease (CIBD) remains one of the most demanding conundra in gastrointestinal pathological practice. It may be difficult to make a definitive diagnosis of CIBD in the acute setting and important infective causes should always be excluded by histopathological, histochemical or microbiological means. Although granulomas are often regarded as virtually diagnostic of Crohn's disease (CD), there are many other, notably infective, causes that may give rise to granulomas and cause diagnostic uncertainty. To confound matters, a definitive diagnosis of either CD or ulcerative colitis (UC) may not be possible in a relatively large number of cases on biopsy, and even at resection, between 10% and 20% will be designated as ‘indeterminate colitis’. This is an important concept that has specific influence on management. CIBD may be causally related to diverticulosis, although mimicry of CIBD by diverticulitis and diverticular colitis is much more likely. The identification of low-grade dysplasia in UC is associated with poor reproducibility; fortunately, recent studies have shifted the emphasis from surgical treatment of dysplasia to endoscopic surveillance and local treatment. There is increasing interest in the histopathological presentation of CIBD in the upper gut. The predictability of focal active gastritis/focally enhanced gastritis for a diagnosis of CD has been recently questioned, and, as always, the context in which pathological features are found is much more important. The vigilant histopathologist is always cautious before making any diagnosis in CIBD pathology without due consideration of the clinical and endoscopic context.