Mitigation and detection of spurious potassium and sodium results.

Spurious laboratory results are results that are analytically correct but do not accurately reflect the in vivo plasma analyte concentrations. Spurious electrolyte results often lead to unnecessary testing or injudicious treatment and have an adverse effect on patient outcome. In this review we discuss the preanalytical and analytical variables that lead to spurious sodium and potassium results. We describe ways to detect them both in the laboratory and in clinical practice and suggest how to prevent them.

Is using WHO criteria for impaired fasting glycaemia appropriate as an indication for OGTT in patients at high risk of developing diabetes?

AIM: Impaired fasting glycaemia (IFG) is an indication for oral glucose tolerance test (OGTT). World health organisation and International Diabetes Federation define IFG as fasting plasma glucose (FPG) levels of 6.1­6.9 mmol/l. However, American Diabetes Association still recommends a range of 5.6­6.9 mmol/l as IFG.We performed an audit to assess the outcome of OGTT at various cut offs of FPG levels in patients at high risk of developing diabetes. METHODS: Laboratory dataon OGTT performed over a period of 1 year in a district general hospital were collected. Patients with FPG levels between 5.6 and 6.9 mmol/l were selected and the outcome was analysed. RESULTS: Our audit shows that in patients with FPG levels of 5.6­6.0 mmol/l, 19% had diabetes and 43% had impaired glucose tolerance (IGT). CONCLUSION: The percentage of subjects with abnormal OGTT in our study is much higher than that of Decode study [Diabetologica, 42 (1999) 647] (7% diabetes and 29% IGT). However, Decode study had included general population whereas our data were collected from subjects who are at high risk of developing diabetes. We conclude that in these subjects the lower cut off level of 5.6 mmol/l for FPG should be used as an indication for OGTT.

Helicobacter pylori infection and adenocarcinoma arising in Barrett's esophagus.

Helicobacter pylori infection has been implicated in the development of chronic active gastritis and gastric neoplasms (ie, mucosa-associated lymphoid tumors and adenocarcinoma). The potential association between esophageal H pylori infection with Barrett's esophagus-associated adenocarcinoma has not been previously studied. Nineteen cases of adenocarcinoma arising in Barrett's esophagus were examined for the presence of H pylori. Barrett's esophagus was defined by the presence of metaplastic specialized-type epithelium (gastric-type epithelium with goblet cell metaplasia) in the distal esophagus. To detect the presence of H pylori, 5-microm sections, from several tissue blocks in each case, were stained with routine hematoxylin-eosin, modified Giemsa, and an antibody directed against H pylori (Dako a/s, Denmark, Lot # 111061). Stained sections were examined independently by two pathologists. All three staining methods failed to show H pylori in any of the cases examined. Sections of Barrett's esophagus (with and without dysplasia), adenocarcinoma, and stomach (when available) were uniformly negative for the presence of H pylori. We conclude that neither gastric nor esophageal infection with H pylori is a requisite for the development of adenocarcinoma in Barrett's esophagus. Moreover, it is unlikely that a significant association between H pylori infection and Barrett's-associated adenocarcinoma exists.

Perinodular hydropic degeneration of a uterine leiomyoma: a diagnostic challenge.

Perinodular hydropic degeneration of a uterine leiomyoma is a rare form of the more common hydropic change observed in leiomyomas. With minimal discussion in the surgical pathology literature, appropriate evaluation may be challenging because the differential diagnosis includes other uncommon uterine disorders such as intravenous leiomyomatosis, diffuse leiomyomatosis, myxoid leiomyosarcoma, endometrial stromal sarcoma, angiofibroma, and angiomyxoma. We describe such a diagnostic challenge in a 42-year-old woman with a left adnexal mass discovered during an annual examination. With only three cases of perinodular hydropic degeneration previously reported, this case is the first with extrauterine extension and was initially concerning for a more aggressive process.

Fluorescent in situ hybridization assessment of chromosome copy number in gestational trophoblastic disease.

The concurrence of congenital trisomy 8 mosaicism and gestational trophoblastic disease in a forty-two-year-old Gravida IV, Para IV female has been described. In contrast to other cases in the literature, this patient had no additional confounding chromosomal abnormalities other than trisomy 8. To the best of our knowledge, this was the only reported case of constitutional trisomy 8 mosaicism associated with gestational trophoblastic disease, a rare gynecological disease entity in and by itself. The present report describes fluorescent in situ hybridization (FISH) studies for assessing chromosome 8 copy number on various patient tissues. The results of the FISH studies are compared with each other and with the original cytogenetic studies. It is concluded that the overall frequency of trisomy 8 cells is lower in the FISH studies using archival material than in the original conventional cytogenetic studies. This is true for the uterus and lung tissues with a metastatic tumor. The possible reasons for the somewhat different frequencies found between conventional cytogenetics via GTG-banding and interphase cytogenetics via FISH are discussed.

Inflammatory pseudotumor of the ileum. A report of a multifocal, transmural lesion with regional lymph node involvement.

Inflammatory pseudotumor (inflammatory fibroid polyp) of the ileum is a rare, usually solitary and polypoid lesion that frequently presents clinically as small-intestinal intussusception and obstruction. Regional lymph nodes are usually not involved. We describe an inflammatory pseudotumor of the ileum that was multifocal, not polypoid, and involved one regional lymph node. Grossly, two circumferential transmural nodules were separated by 8.5 cm of normal ileum. Microscopically, the lesion extended through the muscularis propria into peri-intestinal adipose tissue and involved one noncontiguous regional lymph node. The pseudotumor was composed of highly vascularized stroma with a mixture of spindle cells and chronic inflammatory cells including numerous eosinophils, lymphocytes, plasma cells, histiocytes, neutrophils, and multinucleated giant cells forming small granulomas. Immunohistochemically, the majority of spindle cells reacted with vimentin but not smooth-muscle, endothelial, or lymphoid markers. Ultrastructurally, the spindle cells had abundant rough endoplasmic reticulum, cytoplasmic filaments, and dense bodies consistent with myofibroblasts, plump endothelial cells (some with Weibel-Palade bodies), and chronic inflammatory cells. We prefer the term inflammatory pseudotumor to inflammatory fibroid polyp for the lesion in this case, since it was not polypoid and shared many histologic features with inflammatory pseudotumors arising at sites other than the gastrointestinal tract.

Fertility and infertility statistics: their importance and application.

PIP: To show clearly that an infertility treatment was responsible for the changes leading to pregnancy, comparison needs to be made with defined populations, both of normal subjects and of untreated patients. The comparisons should be made clearly and statistically evaluated. Attention in this discussion of fertility and infertility statistics, their importance and application, is directed to the following: defining the background population; diagnosis of cause of infertility; evaluation of results in infertility patients; some studies illustrating the use of life table analysis; and the design of a randomized control trial. Vessey et al. (1978) calculated the rate for outcome of pregnancy in parous women after stopping barrier contraception and found, using life table analysis, that 36% were undelivered at 12 months. It is possible to calculate the monthly probability of conception or fecundability from cumulative data using the mathematical model described by Potter and Parker (1964). To evaluate the results of treatment, an adequate investigation of the couple is essential. Each of the degrees of impairment of normality in the male can be assessed only when paired with the normal female so that no understatement of fertility may be attributable to a female disorder. Similarly, to be assessable each female abnormality must occur alone in any 1 patient and the partner must be normal. It is only then that the impairment of fertility resulting from a single condition can be determined. In assessing the results in infertility patients, there are 2 main problems: some patients become pregnant and others are lost to follow-up, which progressively depletes the numbers under observation. When numbers in any 1 category are sufficiently large, an effort should be made to subdivide them according to severity. Examples of studies using life table analysis are presented. A table shows the cumulative conception rates in couples with primary infertility who had been investigated and in whom no abnormality was found. They were stratified according to years of infertility rather than from the time they were initially seen in the clinic. This method has been criticized as antedating the period of medical observation, but no treatment was offered. Had the patients been zeroed around the time first seen medically, the findings would have been weighted according to the duration of previous infertility. The apparent effect of treatment on conception rates is also shown.^ieng