Current diagnostic pathology最新文献

There are up to 500 epilepsy-related deaths annually in the UK, many of which are unwitnessed. Likely mechanisms for sudden and unexpected death in epilepsy (SUDEP) are cerebrogenic cardiac arrhythmias, or central respiratory depression occurring during the peri-ictal period. Pathologists should be informed of the circumstances of the death, severity of seizures, seizure control and the certainty of the clinical diagnosis of epilepsy; this allows accurate clinicopathological correlation. SUDEP autopsies include neuropathological assessment, histological examination of other organs and toxicology, and require the elimination of other causes of sudden death. Macroscopic (non-fatal) abnormalities described in SUDEP include evidence of previous cerebral injury, hippocampal sclerosis and cerebellar atrophy. Histological examination may reveal neuronal loss and gliosis consistent with seizure-related brain injury. Hippocampal sclerosis shows subfield-specific patterns of neuronal loss, granule cell dispersion and mossy fibre sprouting. Rarely, acute neuronal injury is seen as evidence of a more recent cerebral event. This article discusses the pathological findings and possible mechanisms in SUDEP, and future directions for pathology-based research.

After a properly conducted autopsy, a small proportion of cases will not reveal a cause of death. This is probably of the order of 2–5%. However, before the death is recorded as unascertained, it is important that appropriate ancillary investigations have been conducted. These tests include toxicology, microbiology and genetic testing where appropriate. The history and scene examination findings must be known, and the possibility of a hidden homicide reasonably excluded. However, even with a full and thorough investigation, some natural disease processes such as cardiac conduction abnormalities and sudden death in epilepsy will result in a negative autopsy. If investigated properly, a cause of death may still be identified for decomposed bodies.

The external examination is an important component of an autopsy, but is often poorly performed and documented. The pathologist has a central role in the external examination, which must be conducted in every case before the evisceration begins. The external examination provides an invaluable opportunity to halt the autopsy and call for expert assistance by detecting evidence that death may be due to trauma. Within the context of autopsies performed at the request of clinicians and autopsies performed on medico-legal authority where an unnatural cause of death is not initially suspected, this article explores the components of the external examination. Particular attention is paid to the examination of identifying features, a search of natural diseases and trauma that may have contributed to the cause of death, and evidence of medical interventions that were attempted to avert death.

Sudden cardiac death is one of the leading causes of death in many different countries. Epidemiologists have refined criteria progressively for the definition of sudden death, while cardiologists have investigated relevant risk factors, especially in patients with cardiac failure and with inherited diseases of cardiac muscle. In contrast, pathologists are responsible for determining the precise cause of sudden death, but there is considerable variation in the way in which they approach this increasingly complex task. In this article, the methods that should be used in routine practice are described. The ideal autopsy involves careful scrutiny of the clinical records, a full macroscopic and microscopic examination, further laboratory tests and the formulation of a final diagnosis. In addition to a full written report, a synoptic proforma summary is desirable. If a uniform method of investigation is adopted, it will lead to improvements in standards of practice, allow meaningful comparisons between different communities and regions, and, most importantly, permit future trends in the patterns of disease that cause sudden death to be monitored.

‘Pseudomyxoma peritonei’ (PMP) is the clinical term traditionally applied to the debilitating syndrome of grossly apparent gelatinous ascites associated with peritoneal deposits of mucinous tumours. For many years, PMP was mainly attributed to mucinous neoplasms arising in the ovary. However, in recent decades, it has become clear that most of this syndrome is related to discontinuous spread from the appendix. Despite the uniformly malignant clinical presentation noted among all histological grades of fully developed PMP, the pathological nomenclature advocated by some authors has continued to include non-malignant terms (reminiscent of the ovarian tumours classified as borderline) for those frequent cases with very-well-differentiated histology. This article will review the clinical and pathological features of PMP in the context of the literature, and maintain that, regardless of how well differentiated they are, all cases of PMP are examples of mucinous carcinoma. Grading as either low- or high-grade carcinoma is indicated for prognostication. This article will also discuss the terminology for mucinous appendiceal neoplasms removed from patients who have not yet developed PMP.

Helicobacter pylori is now accepted as the cause of gastritis and the gastritis-associated diseases (duodenal ulcer, gastric ulcer, and gastric carcinoma). Duodenal ulcer is typically associated with antral-predominant gastritis and little/no atrophy. Gastric ulcer and the intestinal type of gastric cancer are typically associated with extensive gastritis and widespread intestinal metaplasia. The gastritis pattern is determined by a person's acid secretory status, which is the major determinant of disease outcome(s). The natural history of H. pylori gastritis is for the inflammation to progress from the antrum into the adjacent corpus, resulting in an atrophic front of advancing injury, leading to a reduction in acid secretion, loss of parietal cells, and development of atrophy. The pattern, extent, and severity of atrophy with or without intestinal metaplasia are a far more important predictor of atrophy than the intestinal metaplasia subtype. The challenge remains to identify a reliable marker for malignancy potential.

Cutaneous metastases have been described in up to 10% of malignancies. They usually occur after diagnosis of the primary tumour but can be synchronous or even precocious. Identification of the primary source of the metastasis can sometimes be difficult and this paper approaches this in two ways, firstly by discussing the most common types of metastases and secondly by looking at common histopathological patterns. Basic immunophenotypes are discussed. Metastatic lesions must also be distinguished from primary adnexal tumours, and the more common adnexal tumours mimicking metastases are discussed.

This article is the second of two papers relating to the histopathological diagnosis of basaloid skin tumours and the uses of immunohistochemistry. The first paper focused on basal cell carcinoma and variants, and this paper will concentrate on tumours that may be confused with basal cell carcinoma. The basaloid tumours of the skin can be classified according to the general classification of skin tumours, including epidermal, appendageal (hair follicle and sweat gland derived) and others including cutaneous metastases. The areas of discussion concentrate on the distinction of basal cell carcinoma from basaloid squamous cell carcinoma, infiltrative basaloid tumours (desmoplastic trichoepithelioma, infiltrative basal cell carcinoma, microcystic adnexal carcinoma and eccrine epithelioma), follicular induction overlying dermatofibroma, basaloid proliferations in naevus sebaceus, trichoepithelioma, trichoblastoma, trichoepithelioma-like basal cell carcinoma, pilomatrical tumours and selected sweat gland tumours. The immunohistochemical stains that may be of use in differential diagnosis are discussed, including BerEP4, epithelial membrane antigen, CD10, bcl-2, Cam5.2, CK20, carcinoembryonic antigen and p53.

Immunohistochemistry may be useful in the differential diagnosis of epithelial skin tumours in day-to-day practice. This article lists commonly available antibodies, summarizes immunostaining patterns reported in the literature for this group of tumours, highlights immunostaining patterns encountered in normal skin, and emphasizes the immunomarkers that the authors have found to be of particular value. The use of small immunopanels in different diagnostic settings is illustrated.