Interobserver variability in the pathological assessment of malignant colorectal polyps.

BACKGROUND: Treatment of patients with malignant large bowel polyps is highly dependent on pathological evaluation. The aim of this study was to evaluate interobserver variability in the pathological assessment of endoscopically removed polyps. METHODS: The records of 88 patients with colorectal cancer who underwent endoscopic removal of malignant polyps were reviewed. Study investigators reviewed the initial pathology report; three experienced gastrointestinal pathologists reviewed all slides in a blinded fashion. Interobserver variability of pathological assessment of malignant polyps was analysed by kappa statistics. RESULTS: Seventy-six (86 per cent) of the 88 patients had malignant polyps and 12 (14 per cent) had carcinoma in situ. Agreement between experienced pathologists was substantial with regard to T stage (kappa = 0.725), resection margin status (kappa = 0.668) and Haggitt's classification (kappa = 0.682), but comparison of initial and experienced pathologists' assessment demonstrated only moderate agreement in these areas (kappa = 0.516, kappa = 0.555 and kappa = 0.578 respectively). Agreement between even experienced pathologists was poor with respect to histological grade of differentiated adenocarcinomas (kappa = 0.163) and angiolymphatic vessel invasion (kappa = - 0.017). CONCLUSION: Pathological assessment of malignant polyps varies between observers. Specialist pathologists appear to have a higher degree of consensus among themselves than with generalist pathologists with respect to T stage. The high interobserver variability with regard to histological grade of differentiated tumours is clinically irrelevant. However, variability in the assessment of angiolymphatic vessel invasion limits the value of this measurement for clinical decision making.

The effect of fecal occult-blood screening on the incidence of colorectal cancer.

BACKGROUND: Both annual testing for fecal occult blood and biennial testing significantly reduce mortality from colorectal cancer. However, the effect of screening on the incidence of colorectal cancer remains uncertain, despite the diagnosis and removal of precancerous lesions in many persons who undergo screening. METHODS: We followed the participants in the Minnesota Colon Cancer Control Study for 18 years. A total of 46,551 people, most of whom were 50 to 80 years old, were enrolled between 1975 and 1978 and randomly assigned to annual screening, biennial screening, or usual care (the control group). Those assigned to the screening groups were asked to prepare and submit two samples from each of three consecutive stools for guaiac-based testing. Those with at least one positive slide in the set of six were offered a diagnostic examination that included colonoscopy. Screening was conducted between 1976 and 1982 and again between 1986 and 1992. Study participants have been followed with respect to newly diagnosed cases of colorectal cancer and deaths. Follow-up has been more than 90 percent complete. RESULTS: During the 18-year follow-up period, we identified 1359 new cases of colorectal cancer: 417 in the annual-screening group, 435 in the biennial-screening group, and 507 in the control group. The cumulative incidence ratios for colorectal cancer in the screening groups as compared with the control group were 0.80 (95 percent confidence interval, 0.70 to 0.90) and 0.83 (95 percent confidence interval, 0.73 to 0.94) for the annual-screening and biennial-screening groups, respectively. For both screening groups, the number of positive slides was associated with the positive predictive value both for colorectal cancer and for adenomatous polyps at least 1 cm in diameter. CONCLUSIONS: The use of either annual or biennial fecal occult-blood testing significantly reduces the incidence of colorectal cancer.

Calcium supplements for the prevention of colorectal adenomas. Calcium Polyp Prevention Study Group.

BACKGROUND AND METHODS: Laboratory, clinical, and epidemiologic evidence suggests that calcium may help prevent colorectal adenomas. We conducted a randomized, double-blind trial of the effect of supplementation with calcium carbonate on the recurrence of colorectal adenomas. We randomly assigned 930 subjects (mean age, 61 years; 72 percent men) with a recent history of colorectal adenomas to receive either calcium carbonate (3 g [1200 mg of elemental calcium] daily) or placebo, with follow-up colonoscopies one and four years after the qualifying examination. The primary end point was the proportion of subjects in whom at least one adenoma was detected after the first follow-up endoscopy but up to (and including) the second follow-up examination. Risk ratios for the recurrence of adenomas were adjusted for age, sex, lifetime number of adenomas before the study, clinical center, and length of the surveillance period. RESULTS: The subjects in the calcium group had a lower risk of recurrent adenomas. Among the 913 subjects who underwent at least one study colonoscopy, the adjusted risk ratio for any recurrence of adenoma with calcium as compared with placebo was 0.85 (95 percent confidence interval, 0.74 to 0.98; P=0.03). The main analysis was based on the 832 subjects (409 in the calcium group and 423 in the placebo group) who completed both follow-up examinations. At least one adenoma was diagnosed between the first and second follow-up endoscopies in 127 subjects in the calcium group (31 percent) and 159 subjects in the placebo group (38 percent); the adjusted risk ratio was 0.81 (95 percent confidence interval, 0.67 to 0.99; P=0.04). The adjusted ratio of the average number of adenomas in the calcium group to that in the placebo group was 0.76 (95 percent confidence interval, 0.60 to 0.96; P=0.02). The effect of calcium was independent of initial dietary fat and calcium intake. CONCLUSIONS: Calcium supplementation is associated with a significant - though moderate - reduction in the risk of recurrent colorectal adenomas.

Hepatic angiomyolipoma: a clinicopathologic study of 30 cases and delineation of unusual morphologic variants.

Hepatic angiomyolipoma (AML) is frequently misdiagnosed. HMB-45 is a promising immunomarker for this tumor that leads to recognition of some AMLs with unusual morphology. The purpose of this collaborative study is to better define the morphologic variations of AML. Thirty AMLs were examined, including four biopsy specimens and two fine-needle aspirates. The diagnosis was confirmed by the presence of HMB-45-positive myoid cells. Almost half the cases were originally misdiagnosed as carcinomas or sarcomas. There was marked female predominance (25:5), and the mean age was 48.7 years (range 29-68). Three patients (10%) had evidence of tuberous sclerosis and all had renal AML. According to the line of differentiation and predominance of tissue components, the tumors was subcategorized into mixed, lipomatous (> or = 70% fat), myomatous (< or = 10% fat), and angiomatous type. The mixed type was the most common (11 resected cases), comprising sheets of epithelioid muscle cells admixed with islands of adipocytes, abnormal vessels, and frequently, hematopoietic cells. Six tumors (including three from biopsy specimens) were heavily fatty and showed predominantly adipocytes with epithelioid and short spindle myoid cells webbed between fat cells. Of 10 myomatous AMLs, five tumors showed a pure sinusoidal trabecular pattern and comprised mainly epithelioid cells. Typically, mature adipocytes were absent or scanty, but fat was seen as fine droplets within cytoplasm or as occasional large globules in sinusoids. Pelioid and inflammatory pseudotumor-like patterns were identified focally. Regarding cellular features of the myoid cells, most of the epithelioid cells were either eosinophilic or clear with spiderweb cell morphology. Three AMLs showed an almost purely oncocytic appearance with scanty fat. Large pleomorphic epithelioid cells existed as small foci. Spindle cells arranged in long fascicles were uncommon. D-PAS-positive globules were common around pelioid areas. Brown pigments with staining characteristics of hemosiderin and/or melanin were noted. In conclusion, we propose HMB-45-positive myoid cells as the defining criterion of hepatic AML, which is a tumor capable of dual myomatous and lipomatous differentiation and melanogenesis. Because of its protean morphologic appearance, recognition of the various variant patterns and cell types is important for a correct diagnosis, assisted by immunohistochemical confirmation with HMB-45. Trabecular and oncocytic cell tumors appear to stand out as distinctive subtypes.

Calcium supplements and colorectal adenomas. Polyp Prevention Study Group.

Experimental and observational findings suggest that calcium intake may protect against colorectal neoplasia. To investigate this hypothesis, we conducted a randomized, double-blind trial of colorectal adenoma recurrence. Nine hundred thirty patients with a recent history of colorectal adenomas were randomly given calcium carbonate (3 gm daily; 1200 mg elemental calcium) or placebo, with follow-up colonoscopies one and four years after the qualifying examination. The main analysis focused on new adenomas found after the first follow-up endoscopy, up to (and including) the second follow-up examination. Risk ratios of at least one recurrent adenoma and ratios of the average numbers of adenomas were calculated as measures of calcium effect. There was a lower risk of recurrent adenomas in subjects assigned calcium. Eight hundred thirty-two patients had two follow-up examinations and were included in the main analysis; the adjusted risk ratio of one or more adenomas was 0.81 (95% CI 0.67 to 0.99); the adjusted ratio of the average numbers of adenomas was 0.76 (95% CI 0.60 to 0.96). Among subjects who had at least one follow-up colonoscopy, the adjusted risk ratio of one or more recurrent adenomas was 0.85 (95% CI 0.74 to 0.98). The effect of calcium seemed independent of initial dietary fat and calcium intake. No toxicity was associated with supplementation. These findings indicate that calcium supplementation has a modest protective effect against colorectal adenomas, precursors of most colorectal cancers.

Follow-up after liver transplantation for protoporphyric liver disease.

Protoporphyria is a genetic disorder in which patients may develop severe protoporphyrin-induced liver damage and require transplantation. Because unique problems occur in the perioperative period and because excess production of protoporphyrin by the bone marrow continues after liver transplantation, the efficacy of this procedure for protoporphyric liver disease is uncertain. We present follow-up of nine patients who underwent liver transplantation. Two patients died within 2 months of transplantation, one from complications of abdominal bleeding and the other from sepsis after bowel perforations. The remaining seven patients had follow-up at 14 months to 8 years after transplantation (mean, 3.8 years). Two of the seven had suffered skin burns from exposure to operating room lights, which healed without scarring. Three had axonal neuropathies in the postoperative period requiring prolonged mechanical ventilation, and motor defects persisted in two. Five patients had normal liver chemistries at follow-up (mean, 3.5 years), with liver biopsy results normal or showing mild portal triad abnormalities, but erythrocyte protoporphyrin levels remained significantly elevated (1,765 +/- 365 mcg/dL; normal, < 65). The other two patients, both of whom had rejection, cytomegalovirus infection, and biliary tract obstruction requiring endoscopic therapy, had a recurrence of protoporphyric liver disease as indicated by liver biopsy features. One died 5 years after transplantation from complications of the liver disease. The other was stable 3.3 years after transplantation and was being monitored for possible retransplantation. Thus, liver transplantation can be performed successfully in patients with protoporphyric liver disease, with intermediate survival rates comparable to the general transplant population. However, disease may recur in the graft, particularly if there are complications that cause cholestasis.

Serrated adenomatous polyposis in humans.

BACKGROUND & AIMS: Hyperplastic polyposis clinically resembles adenomatous polyposis and has not generally been considered precancerous. However, since the original description, a number of cases associated with adenocarcinoma have been reported. The aim of this study was to reevaluate patients previously diagnosed with hyperplastic polyposis. METHODS: Pathological analysis of polyps in 6 patients with putative hyperplastic polyposis and 4 with associated carcinoma was compared with classic isolated hyperplastic polyps, adenomas, and solitary serrated adenomas. Immunohistochemical study for the detection of p53 protein, blood groups antigens, including Lewis(a) and Lewis(b), and peanut lectin binding was performed. RESULTS: Polyps in our patients were much more similar to serrated adenomas than to hyperplastic polyps and were characterized by large size, prominent architectural distortion, cytologically atypical nuclei, focal nuclear crowding and nuclear dispolarity, and rare upper zone mitotic figures. The polyps in our patients and control serrated adenomas had a decrease or absence of endocrine cells compared with classic hyperplastic polyps and normal colon and similar immunohistochemical reactivity for p53 and Lewis(a) and Lewis(b) antigens. CONCLUSIONS: Our results indicate that the polyps in our patients are serrated adenomas. Serrated adenomatous polyposis has not been described before and should be distinguished from true hyperplastic polyposis given a possible association with adenocarcinoma in the former group.

Hepatic levels of cyclosporine and metabolites in patients after liver transplantation.

Despite the critical role of the liver in the metabolism of cyclosporine, only a few studies have measured hepatic levels (CSAH) in patients receiving the drug, and none has directly assayed hepatic levels of the metabolites. In this study we measured CSAH and its principal metabolites (mono-OH and di-OH CSA) by HPLC/mass spectroscopy in 19 liver biopsy specimens collected from 14 patients who had undergone liver transplantation, in order to determine how they correlated with blood levels (CSAB). The hepatic concentrations were also compared with biochemical and histological parameters of cholestasis. A positive correlation was observed between CSAH and CSAB (r = 0.47), irrespective of the length of time the patients had received the drug (7 to 1662 days) as defined by the relationship: CSAH(ng/g wet weight) = 6.7 x CSAB(ng/ml)+338. Hepatic levels of metabolites exceeded those of the parent compound in 11 biopsy specimens. No correlation was found for CSAH and the metabolites and serum bilirubin or the degree of cholestasis in the liver biopsy specimens. These findings indicate that: (1) CSA is concentrated in liver tissue several-fold over blood; (2) The hepatic concentration can be estimated from the blood concentration even in the presence of cholestasis; (3) Significant levels of CSA metabolites are found in liver tissue, frequently exceeding the concentration of the parent compound.

Frequent polymorphism in exon 15 of the adenomatous polyposis coli gene.

In the course of a study of tumor suppressor gene mutation in hepatoblastoma, a frequent neutral polymorphism was identified at codon 1493 in exon 15 of the gene causing adenomatous polyposis coli (APC). As the polymorphism introduces a new BsaJ1 site, DNA amplified by the polymerase chain reaction (PCR) can be rapidly screened for this polymorphism. This polymorphism can be used in cosegregation studies for presymptomatic diagnosis of APC and family studies.

Light and electron microscopic features of the liver in mucopolysaccharidosis.

The mucopolysaccharidosis (MPS) diseases lead to the accumulation of glycosaminoglycan in many tissues. In this study 19 MPS I, one MPS II, five MPS III, and two MPS VI patients underwent liver biopsy for light and electron microscopic examination. Electron microscopy was performed for all 27 specimens. Twenty-six specimens were studied by light microscopy, and the slides were stained with colloidal iron and alcian blue in 26 and six biopsy specimens, respectively. By hematoxylin-eosin stain 20 of 26 cases showed hepatocellular dilatation with rarefaction of the cytoplasm; the Kupffer cells were unremarkable. Twenty-four and 25 of the 26 biopsy specimens showed substantial colloidal iron staining of hepatocytes and Kupffer cells, respectively. The six biopsy specimens prepared with alcian blue stain showed no reactivity of any cell type. Electron microscopy revealed characteristic membrane-bound inclusions within the hepatocytes and Kupffer cells of all 27 biopsy specimens. Of 19 cases in which Ito cells were identified, 18 included cells containing similar inclusions. Twenty of 27 biopsy specimens also demonstrated the hepatocellular accumulation of lipid droplets. Although there were no absolute distinguishing features among the various MPS diseases, the two MPS VI cases showed glycosaminoglycan inclusions that were fewer in number, smaller, and contained more abundant lipofusion than those associated with the other MPS types.

Histologic pathology of the liver in progressive familial intrahepatic cholestasis.

This work details the histologic findings in 84 liver biopsy specimens from 28 patients with progressive familial intrahepatic cholestasis (PFIC), who met the clinical criteria of early onset of chronic unremitting cholestasis, exclusion of any known metabolic or anatomic etiology, and low serum gamma-glutamyl transpeptidase (GGTP) values. Hepato-canalicular cholestasis and disruption of the liver cell plate arrangement were early, uniform findings, and giant cell transformation was found in 56% of initial biopsies. Duct loss was a prominent finding; 70% of patients had ductal paucity, and many had abnormal bile duct epithelium, suggesting degeneration. Fibrosis was seen in the samples from 16 patients, including bridging fibrosis in specimens obtained from six patients during the first 2 years of life. Proliferating ductules at the margins of portal tracts increased as fibrosis progressed and were especially prominent in end-stage histology. Cirrhosis developed in nine of these patients and had a characteristic histologic pattern, consisting of biliary cirrhosis with diffuse stellate lobular fibrosis associated with severe cholestasis and pseudoacinar transformation. Mallory hyalin and hepatocellular carcinoma were observed in materials from some patients with advanced cirrhosis. The constellation of histologic findings in PFIC forms a recognizable pattern, and the liver histology appears to have a predictable progression.

Murine recipients of fully mismatched donor marrow are protected from lethal graft-versus-host disease by the in vivo administration of rapamycin but develop an autoimmune-like syndrome.

We investigated the ability of the macrolide antifungal agent rapamycin (RAPA) to inhibit murine graft-vs-host disease induced across the MHC barrier. An optimum dose (1.5 mg/kg) given for 14 days beginning on the day of transplant (and then three times weekly until 1 mo) effectively and significantly (p < 0.001) protected 80% of irradiated B10.BR recipients of C57Bl/6 bone marrow/spleen grafts for over 90 days, whereas 80% of control mice died by day 37. Using a congenic model in which a mixture of Ly5.1+ bone marrow (T cell-depleted) and Ly5.2+ spleen cells allowed us to distinguish mature and immature cells, we found that RAPA inhibits the splenic expansion of mature donor-derived T cells in B10.BR recipients after bone marrow transplantation. In addition, phenotyping studies revealed that RAPA causes a massive reduction of immature CD4+CD8+ T cells in the thymus, indicating that RAPA probably interferes with maturation of immature CD3-CD4-CD8- T cells to CD4+CD8+ T cells. There was also a predilection toward development or intrathymic retention of the more mature CD3+CD4-CD8+ or CD3+CD4+CD8- cells in the thymus of long term survivors. These same observations were made in different experiments with mice given syngeneic bone marrow transplantation and RAPA. However, RAPA administration was associated with the occurrence of an autoimmune-like syndrome, consisting of ulcerative dermatitis, hepatic bile duct proliferation, and nondestructive lymphoid peribronchiolar infiltration of the lung. RAPA interfered with the deletion of potentially self-reactive T cells that occurs in thymic development. The failure of clonal deletion was observed in allogeneic and syngeneic transplants given RAPA, although only the allografted mice experienced an autoimmune-like syndrome. Some, but not all, of the nondeleted V beta populations were functionally active. These new findings bear certain dissimilarities to the syndrome and lesions observed with cyclosporin A treatment, particularly in the observation of bile duct proliferation and ulcerative skin lesions. Nonetheless, because of the potent effect of RAPA in preventing lethal graft-vs-host induced across the MHC, further investigation of the immune consequences of this highly effective compound is warranted.

Role of mesenchymal cell death in lung remodeling after injury.

Repair after acute lung injury requires elimination of granulation tissue from the alveolar airspace. We hypothesized that during lung repair, signals capable of inducing the death of the two principal cellular elements of granulation tissue, fibroblasts and endothelial cells, would be present at the air-lung interface. Bronchoalveolar lavage fluid obtained from patients during lung repair induced both fibroblast and endothelial cell death, while fluid obtained at the time of injury or from patient controls did not. The mode of cell death for endothelial cells was apoptosis. Fibroblast death, while morphologically distinct from necrosis, also differed from typical apoptosis. Only proliferating cells were susceptible to the bioactivities in lavage fluid, which were trypsin sensitive and lipid insoluble. Histological examination of lung tissue from patients after lung injury revealed evidence of apoptotic cells within airspace granulation tissue. Our results suggest that cell death induced by peptide(s) present at the air-lung interface may participate in the remodeling process that accompanies tissue repair after injury.

Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study.

BACKGROUND: Although tests for occult blood in the feces are widely used to screen for colorectal cancers, there is no conclusive evidence that they reduce mortality from this cause. We evaluated a fecal occult-blood test in a randomized trial and documented its effectiveness. METHODS: We randomly assigned 46,551 participants 50 to 80 years of age to screening for colorectal cancer once a year, to screening every two years, or to a control group. Participants who were screened submitted six guaiac-impregnated paper slides with two smears from each of three consecutive stools. About 83 percent of the slides were rehydrated. Participants who tested positive underwent a diagnostic evaluation that included colonoscopy. Vital status was ascertained for all study participants during 13 years of follow-up. A committee determined causes of death. A single pathologist determined the stage of each tissue specimen. Differences in mortality from colorectal cancer, the primary study end point, were monitored with the sequential log-rank statistic. RESULTS: The 13-year cumulative mortality per 1000 from colorectal cancer was 5.88 in the annually screened group (95 percent confidence interval, 4.61 to 7.15), 8.33 in the biennially screened group (95 percent confidence interval, 6.82 to 9.84), and 8.83 in the control group (95 percent confidence interval, 7.26 to 10.40). The rate in the annually screened group, but not in the biennially screened group, was significantly lower than that in the control group. Reduced mortality in the annually screened group was accompanied by improved survival in those with colorectal cancer and a shift to detection at an earlier stage of cancer. CONCLUSIONS: Annual fecal occult-blood testing with rehydration of the samples decreased the 13-year cumulative mortality from colorectal cancer by 33 percent.

Histochemical and immunohistochemical characterization of cells constituting the giant cell tumor of bone.

Enzymatic activity and cell membrane proteins were characterized in cells from five giant cell tumors of bone (GCTs). Naphthyl alpha esterase (NAE) and acid phosphatase (AP) activity was noted within both the mononuclear and multinucleated cells of each tumor. In each tumor, all mononucleated cell populations displayed tartrate-sensitive AP activity, whereas the multinucleated cell populations demonstrated variable expression of tartrate-sensitive and tartrate-resistant AP activity. Analysis of cell membrane proteins included attempts at immunodetection of mannose receptor, OKM-1 antigen (OKM-1a), colony-stimulating factor-1 receptor (CSF-1r), and platelet-derived growth factor receptor (PDGFr). None of these membrane antigens were elicited on multinucleated cells. In contrast, the mannose receptor, OKM-1a, and PDGFr all were detected on the mononucleated cells within each tumor. These data demonstrate that a population of mononucleated, not multinucleated cells, expresses features unique to mature mononuclear phagocytes and establishes the presence of a membrane receptor, PDGFr, associated with mitogenesis of mesenchymal cells.

Nonmitogenic anti-CD3F(ab')2 fragments inhibit lethal murine graft-versus-host disease induced across the major histocompatibility barrier.

We have investigated the in vivo administration of nonmitogenic anti-CD3F(ab')2 fragments for the prevention of lethal graft-vs-host disease (GVHD) in irradiated recipients of fully allogeneic bone marrow cells plus splenocyte (BMS) inocula. Recipients of anti-CD3F(ab')2 fragments administered for 1 mo post-bone marrow transplantation (BMT) had 100% survival without clinical or histopathological evidence of GVHD. Controls given saline injections succumbed by 39 days post-BMT. Similar results were obtained in groups of recipient mice given BMS in which T cells were depleted by in vitro anti-Thy-1.2 plus C' treatment. Further studies were undertaken to define mechanistic differences in the two approaches. Using Ly-5 congenic sources of donor bone marrow and spleen, we determined that anti-CD3F(ab')2 fragments induced TCR modulation and T cell depletion. Mature splenic-derived CD4+ cells were depleted to a greater extent than CD8+ cells. Early post-BMT, recipients receiving injections with control saline had the highest number of CD4+ and CD8+ cells (which may cause GVHD) followed by recipients of anti-CD3F(ab')2 fragments, with the fewest CD8+ cells observed in the anti-Thy-1.2 + C' treated group. CD3+CD4-CD8- cells (which may suppress GVHD generation) were present in higher numbers early post-BMT in recipients given anti-CD3F(ab')2 fragments as compared to recipients given anti-Thy-1.2 + C'-treated BMS. In long term survivors, a mononuclear T cell containing infiltrate without evidence of destruction was observed in sites of GVHD (lung and liver), consistent with a "Quilty" effect, which was not observed in either of the other two groups. Although survivors were tolerant of donor skin grafts and rejected third party grafts, recipients given anti-CD3F(ab')2 fragments but not anti-Thy-1.2 + C'-treated BMS had vigorous anti-host proliferative responses. These results demonstrate that although in vitro anti-Thy-1.2 + C' treatment of BMS (which is highly depletionary) and in vivo administration of anti-CD3F(ab')2 fragments (which is modulatory and less depletionary) are both effective strategies for GVHD, the cellular events involved in achieving GVHD prevention are indeed different.