The lighter side of myeloma: an easily overlooked diagnosis.
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Alkaline Phosphatase↗
Biomedical subjects
M Guindi
Publications and source records attributed to M Guindi.
Indeterminate colitis.
Indeterminate colitis (IC) originally referred to those 10-15% of cases of inflammatory bowel disease (IBD) in which there was difficulty distinguishing between ulcerative colitis (UC) and Crohn's disease (CD) in the colectomy specimen. However, IC is increasingly used when a definitive diagnosis of UC or CD cannot be made at colonoscopy, in colonic biopsies or at colectomy. The diagnostic difficulties may explain the variably reported prevalence of IC. Clinically, most patients with IC evolve to a definite diagnosis of UC or CD on follow up. The role of ancillary tests in the distinction of UC from CD is reviewed. The low sensitivity of serological markers limits their usefulness. Other tests include upper endoscopy and magnetic resonance imaging. The definition of IC may not be a purely histological one derived from resected specimens, but rather a clinicopathological one. This review offers some personal observations and viewpoints, and proposes an approach to some of the relatively more esoteric combinations of findings.
Colectomy↗
The pathology of epithelial pre-malignancy of the gastrointestinal tract.
This chapter deals with pre-malignant epithelial lesions of the gastrointestinal tract that have the potential to become cancers. Pre-malignant lesions are divided into two types: those characterized by dysplastic mucosa and those without dysplasia. Examples of the two types are present in the oesophagus, stomach and intestine. In the oesophagus, dysplasia of the squamous epithelium is a precursor to squamous carcinoma. There are differences in interpretation between Western and Japanese pathologists in the diagnosis of oesophageal squamous lesions. Dysplasia in Barrett's oesophagus is regarded as a precursor of adenocarcinoma. The goal of endoscopic surveillance in Barrett's mucosa is the detection of high-grade dysplasia. There are several problems with our current knowledge of high-grade dysplasia and controversies regarding its management. There are differences in the interpretation of biopsies of gastric epithelial dysplasia between Japanese and Western pathologists. In the colon, pre-malignant lesions include dysplasia seen in inflammatory bowel disease and colonic adenomas. The most significant predictor of the risk of malignancy in patients with inflammatory bowel disease is the presence of dysplasia in colonic biopsies. Because of the similarity of neoplasia throughout the gastrointestinal tract, there have been attempts to unify its classification, terminology and diagnostic criteria internationally, the most recently proposed modified classification of gastrointestinal neoplasia being the Vienna classification. Dysplasia of the columnar mucosa has a similar appearance in Barrett's oesophagus, the stomach and the colon. Criteria for its histological diagnosis and grading are reviewed, with an emphasis on areas of diagnostic difficulty such as interobserver variation, and discrepancies between Western and Japanese pathologists. Implication of the presence of dysplasia that are specific to each organ site are discussed, highlighting weaknesses and controversies in current knowledge.
Carcinoma↗
Role of activated host T cells in the promotion of MALT lymphoma growth.
Gastric mucosa-associated lymphoid tissue (MALT) B cell lymphomas contain activated helper T cells. The evidence supports the presence of mechanisms of T cell dependence underlying the development of these lymphomas. It appears that the T cells, which activate B cells, may contribute to lymphoma pathogenesis. Co-stimulatory molecules necessary for effective B cell/T cell interaction are expressed in MALT lymphomas. The studies suggest that CD40 signaling, in combination with cytokines, is essential for the development and progression of MALT lymphomas. Activated T cells of low grade gastric MALT lymphoma, while delivering full help to B cells, are apparently deficient in two cytotoxic mechanisms involved in the concomitant control of B cell growth.
Cytotoxicity, Immunologic↗
Role of Helicobacter pylori in the pathogenesis of gastric carcinoma and progression of lymphoid nodules to lymphoma.
The pathology of gastritis associated with Helicobacter pylori infection is summarized. The literature is reviewed regarding the role of H pylori in the pathogenesis of gastric carcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. The potential mechanisms of gastric carcinogenesis include transformation of the gastric mucosa by metabolic products of H pylori, transformation of the host cell by incorporation of H pylori DNA and genotoxic effects of the inflammatory response to the organism. A model for gastric carcinogenesis is proposed in which H pylori causes cell proliferation, and the risk of DNA damage is increased, leading to inadequate repair and malignant transformation. Investigation of early gastric carcinomas concluded that two main pathways operated in gastric carcinogenesis, both starting from H pylori gastritis and leading to phenotypically variable gastric or intestinal tumour growth. The histological features and molecular genetics of MALT lymphoma are briefly reviewed. There is evidence that tumour cells of low grade B cell MALT lymphoma proliferate specifically in response to H pylori. This response is dependent on T cell activation by H pylori. A proposed model for the pathogenesis of MALT lymphoma postulates that B lymphocytes with a genetic change acquire a growth advantage resulting in a monoclonal proliferation in response to H pylori-activated T cells. Further genetic changes may result in escape from T cell dependency.
Gastric Mucosa↗
Calcification in colorectal hepatic metastases correlates with longer survival.
BACKGROUND: Calcification occurs in 12-27% of hepatic colorectal metastases, but its clinical significance and its influence on prognosis are unknown. METHODS: All patients diagnosed with colorectal liver metastases at the Ottawa Regional Cancer Center in 1991 (n = 97), as well as those enrolled in chemotherapy trials in 1990-1992 (n = 51), were entered into a retrospective cohort study. Thirty-six patients were excluded due to inadequate follow-up. In the remaining 112, abdominal CT scans and/or ultrasound examinations were used to determine the presence of calcification. Charts were reviewed for variables, including primary tumour pathology, amount of liver involvement by tumour (< 25%, 25-50%, > 50%), and the chemotherapeutic agents received, and were subjected to multivariate and regression analysis. End point was survival in months or to December 1993 (median follow up 24 months). RESULTS: Patients with calcification (n = 31) (28%) were compared to those who did not have calcifications (n = 81). The groups were comparable with respect to sex, age, time to calcification, time to metastases, and treatment type. Calcification occurred independent of the degree of tumour differentiation, the presence of mucinous adenocarcinoma, or the hepatic tumour burden. Nine patients with calcified metastases (30%) had calcification at presentation. Biopsies showed calcification next to viable tumour cells with an absence of an inflammatory reaction. Survival was improved with better primary tumour differentiation and less tumour burden. The presence of calcification had a statistically highly significant improvement in survival (P < 10(-6), relative risk = .19) independent of other variables. CONCLUSIONS: The presence of calcification within a colorectal liver metastasis appears to imply a significantly better prognosis.
Aged↗
Is rectal biopsy necessary in irritable bowel syndrome?
Many physicians obtain a rectal biopsy from patients with irritable bowel syndrome (IBS) in order to exclude melanosis coli and collagenous or microscopic colitis. To determine the value of routine rectal biopsy in IBS, 89 patients and 59 controls were administered a bowel questionnaire, and a rectal biopsy was obtained at sigmoidoscopy. IBS patients were 82% female and averaged 44 yr. Eighty-nine percent fulfilled three or more Manning criteria, and 84% fulfilled the Rome criteria for IBS. The 59 control subjects were 37% female, and averaged 57 yr. Only 15% fulfilled three or more Manning criteria, and 5% the Rome criteria. The 148 rectal biopsies were examined histologically by a pathologist whose methods were validated by a second pathologist. Although minor changes previously reported with phosphate enemas were observed, not a single subject had melanosis coli or fulfilled criteria for microscopic or collagenous colitis. Thus, patients with an endoscopically normal colon and a diagnosis of IBS made by established criteria are unlikely to have histologic abnormalities in the rectum. Rectal biopsies are costly and unnecessary in the investigation of IBS.
Adult↗
Giant cell arteritis (temporal arteritis) affecting the breast: report of two cases and review of published reports.
The breast is an infrequently recognised site of primary giant cell arteritis. Two cases of giant cell arteritis affecting the breast are described and 11 previously described cases are reviewed. All cases presented with single or multiple breast masses, leading to a diagnosis before biopsy of suspected breast carcinoma. Symptoms similar to those of polymyalgia rheumatica occurred in about half of these patients, though the significance of these symptoms was only appreciated in retrospect. Clinical or pathological evidence of giant cell arteritis outside the breast (temporal artery, thyroid artery) was noted in a minority of cases. Seven patients received corticosteroid treatment, and all patients recovered without complications. Two patients had an adenocarcinoma of the breast contiguous with the giant cell arteritis. Giant cell arteritis affecting the breast may be underrecognised and should be considered in older women with polymyalgia rheumatica-like symptoms and tender breast mass(es).
Aged↗
An unusual tumor of the lung. Postinflammatory pseudotumor (benign histiocytoma) of lung.
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Adolescent↗
Fine needle aspiration biopsy of hepatocellular carcinoma. Value of immunocytochemical and ultrastructural studies.
Over three years, 365 fine needle aspiration biopsies (FNABs) of the liver were performed at Ottawa Civic Hospital. Fifty-nine percent of these aspirates were positive for malignancy. A diagnosis of hepatocellular carcinoma (HCC) was made in 20 liver aspirates. The initial light microscopic diagnoses of HCC were confirmed by immunocytochemical and/or electron microscopic (EM) studies in 16 aspirates. Canalicular pattern of staining with antibody to carcinoembryonic antigen (CEA), positive staining with anticytokeratin AE3 and negative staining with anticytokeratin AE1 supported the diagnosis of HCC. Although alpha-fetoprotein (AFP) expression is relatively specific for HCC, it was positive in only 44% of cases, and the staining was usually focal. EM study confirmed the diagnosis of HCC in seven cases. Based on our findings and published reports, we use a diagnostic panel of antibodies to CEA, AFP and anticytokeratins AE1 and AE3, and/or EM study when there is a suggestion of HCC cytologically or clinically.
Biomarkers, Tumor↗