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D C Snover

Publications and source records attributed to D C Snover.

At least 73 records · Page 4Linked to original sources

Progressive bile duct injury after thiabendazole administration.

A 27-yr-old man developed jaundice 2 wk after exposure to thiabendazole. Cholestasis persisted for 3 yr, at which time a liver transplant was performed. Two liver biopsy specimens and the hepatectomy specimen were remarkable for almost complete disappearance of interlobular bile ducts. Prominent fibrosis and hepatocellular regeneration were also present; however, the lobular architecture was preserved. This case represents an example of "idiosyncratic" drug-induced liver damage in which the primary target of injury is the bile duct. An autoimmune pathogenesis of the bile duct destruction is suggested.

Adult↗

Liver allograft rejection. An analysis of the use of biopsy in determining outcome of rejection.

Two-hundred-seventy biopsy specimens from 47 patients undergoing liver transplants at the University of Minnesota were analyzed to determine if histological features could predict the eventual outcome of rejection episodes. Thirty-six patients (76.6%) rejected the transplant. Of these, five either suffered acute liver failure due to rejection (two cases) or developed chronic rejection (three cases). Features of significance in predicting such a bad outcome were arteritis, bile duct paucity, or simultaneous hepatocellular ballooning and hepatocellular dropout and necrosis. Other features, such as type and intensity of infiltrate, degree of bile duct damage, or simple presence of hepatocellular necrosis, were not predictive of outcome. Our conclusion is that biopsy is useful in predicting outcome. Since many of the histologic findings of predictive value were not present in initial pretreatment biopsy specimens, follow-up biopsies of patients being treated for rejection are recommended to assess efficacy of therapy.

Adolescent↗

Cytomegalovirus infection of the liver in transplant recipients.

Thirty-two transplant recipients with cytomegalovirus (CMV) infection documented by positive culture of blood and/or organs other than the liver were evaluated for hepatic involvement. Thirteen of the 32 (41%) had evidence of hepatic involvement with CMV. Inclusions alone were present in three patients; liver cultures alone were positive for CMV in three; and both were present in seven. Although the presence of CMV inclusions was the only histological feature that clearly separated the groups with and without hepatic involvement, two items helpful in finding inclusions were lobular aggregates of polymorphonuclear cells and portal karyorrhexic debris. The presence of liver involvement had a significant correlation with multiple organ infection, indicating it is a good marker of widely disseminated disease. This study indicates that liver histology and culture are useful and complementary methods for documentation of hepatic involvement (hence, tissue invasion) in immunocompromised patients with CMV infection.

Cytomegalovirus Infections↗

Increased expression of class I major histocompatibility complex antigens on hepatocytes in rejecting human liver allografts.

We studied hepatocellular expression of major histocompatibility (MHC) antigens in 43 serial liver transplant biopsies from 22 patients (42 percutaneous, 1 autopsy specimen), 4 normal liver biopsies, and 8 percutaneous biopsies of diseased livers from non-liver-transplant patients. Frozen tissue sections were stained by an indirect immunofluorescence technique using monoclonal antibodies (MCAb) that recognize nonpolymorphic human class I or class II MHC determinants. Ethidium bromide was used to stain nuclei and rhodamine-conjugated anti-basement-membrane antibodies to delineate epithelial and vascular structures. HLA-DR antigens recognized by MCAb OKIa1 and I2 were not detected on hepatocytes but were detected on the bile duct epithelium in 7 of 27 transplant biopsies, including 5 with acute rejection and 1 with chronic liver disease that later progressed to chronic rejection. HLA-A, B, C antigens recognized by MCAb 34/28 intensely stained cells lining the liver sinusoids but were negative on hepatocytes in 4 normal liver biopsies and 7 of 8 non-transplant biopsies. Expression of class I MHC antigens on hepatocyte membranes was increased in 17 of 21 (81%) biopsies from patients with acute rejection, in 4 of 4 with chronic transplant liver disease, but in only 3 of 18 (17%) biopsies from patients with no rejection (chi square = 8.62, P less than 0.01). Our observations demonstrate increased expression of MHC class I antigens in association with acute rejection in human orthotopic liver transplantation. Histologic resolution of the rejection episode is generally followed by a decrease in hepatocyte class I antigen expression. Further analysis of this response may have value in assessing the severity of the rejection and effectiveness of treatment.

Antibodies, Monoclonal↗

Abdominal sonography after hepatic transplantation: results in 36 patients.

Hepatic transplantation was performed in 46 patients over a 2-year period at the University of Minnesota. Thirty-six of these patients subsequently underwent 166 sonographic examinations of the upper abdomen. Forty-three examinations were performed within 2 weeks of transplantation, 47 between 2 and 8 weeks after transplantation, and 76 more than 8 weeks after transplantation. The sonograms were reviewed retrospectively and correlated with the available clinical and histopathologic data. Diffuse, nonspecific parenchymal abnormalities were seen in 27 patients. Focal regions of parenchymal abnormality seen in four patients were associated with abscess and infarction. Moderate to severe biliary dilatation was seen in seven patients with biliary obstruction diagnosed by percutaneous or T-tube cholangiography. Obstruction was seen most commonly in children who had undergone cholecystojejunostomy biliary reconstruction, and it required radiologic or surgical intervention. Routine sonographic assessment of the upper abdominal vasculature showed thrombosis of the portal vein in two cases, thrombosis of the inferior vena cava in one case, thrombosis of the donor aorta in three cases. Focal intraabdominal fluid collections were identified in 14 patients and represented hematomas in all but one. Free peritoneal fluid was detected in 19 patients. Sonography was used to guide percutaneous aspiration of abdominal fluid and to guide fine-needle puncture for percutaneous transhepatic cholangiography. Upper abdominal sonography provides a noninvasive means of evaluating and confirming a wide spectrum of complications that can follow hepatic transplantation. Because clinical and laboratory findings often are nonspecific in these patients, sonographic detection of focal parenchymal abnormalities, biliary dilatation, and vascular compromise is especially valuable.

Abdomen↗

Fibroadenomatosis (fibroadenomatoid mastopathy): a benign breast lesion with composite pathologic features.

A benign breast lesion with the composite histologic features of a fibroadenoma and fibrocystic changes has been referred to previously as fibroadenomatosis or fibroadenomatoid mastopathy; this lesion is distinct from the typical well circumscribed fibroadenoma that may have fibrocystic changes. The purpose of our study was to ascertain the frequency of this change among 200 consecutive breast biopsies and excisions with a coded pathologic diagnosis of fibroadenoma and/or "fibrocystic disease"; we identified these changes in 23 (11.5%) specimens. The lesion was characterized by microscopic fibroadenomatoid foci intermingled with dilated ducts, epitheliosis, and adenosis. It is suggested that fibroadenomatosis is yet another pattern in the complex morphologic spectrum known as benign proliferative breast disease. From our experience, this particular lesion was often appreciated as a unique finding, but the appropriate diagnostic designation was in question. The natural history of fibroadenomatosis is essentially unknown. It may represent a morphologic stage in the development of fibroadenoma(s).

Adenofibroma↗

Cowden's disease.

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Breast Neoplasms↗

Neuromas of the appendix. A light-microscopic, immunohistochemical and electron-microscopic study of 20 cases.

The neural origin and even the existence of appendiceal neuromas have been questioned. We have studied 20 examples, 7 discovered during a prospective examination of 26 consecutive routine appendectomy specimens (for an incidence of 27%), 2 selected from random cases, and 11 discovered in a retrospective review of 11 randomly selected cases of appendices diagnosed as "fibrous obliteration." By light-microscopy, appendiceal neuromas appear as a loose proliferation of spindle cells usually in a myxoid background, frequently with entrapped fat and connective tissue and infiltrated by eosinophils. Seventeen were located centrally in the appendix without nodule formation. One was central with nodularity and two were confined to the mucosa. The spindle cells were positive for S-100 protein and neuron-specific enolase in all cases. In 12, serotonin positive cells entrapped in the proliferation were present. In 5 of 11 cases with apparent uninvolved appendix present in the specimen, the number of serotonin cells in the crypts was greater than in normal appendix controls. Two appendiceal neuromas contained somatostatin positive cells. Stains for vasoactive intestinal polypeptide, substance P, neurotensin, bombesin and gastrin were negative. Ultrastructural examination of one case confirmed the presence of a mixture of Schwann cells and cells containing neurosecretory granules. We conclude that appendiceal neuroma is a rather common entity, and that most cases of so-called fibrous obliteration actually represent appendiceal neuroma.

Adolescent↗

Primary duodenal small-cell neuroendocrine carcinoma with production of vasoactive intestinal polypeptide.

A primary duodenal small-cell neuroendocrine carcinoma was found in an elderly man who presented with upper abdominal pain. Although metastatic small-cell carcinoma was documented by liver biopsy, the primary lesion was not identified until postmortem examination. The latter tumor, which ulcerated the duodenal mucosa, was composed of small ovoid cells with sparse cytoplasm and granular chromatin. Electron microscopy revealed cytoplasmic dense-core granules. Immunocytochemical study demonstrated the presence of neuron-specific enolase, Leu 7 antigen, chromogranin, epithelial membrane antigen, and vasoactive intestinal polypeptide within tumor cells. However, there was no evidence of a clinical endocrinopathy. This case emphasizes the need to include the duodenum as a possible primary site when metastatic small-cell neuroendocrine carcinoma is seen in the absence of apparent pulmonary disease.

Aged↗

Bronchiolitis obliterans after bone marrow transplantation.

Bronchiolitis obliterans occurred in the setting of chronic graft-versus-host disease 1 year after allogeneic bone marrow transplantation for chronic myelogenous leukemia. The severe obstructive pulmonary disease followed an episode of interstitial pneumonitis. The etiology and possible relationship to graft-versus-host disease of this rare pulmonary lesion following bone marrow transplantation are discussed.

Adult↗

Cryptosporidiosis as a cause of diarrhea following bone marrow transplantation.

Severe diarrhea following bone marrow transplantation may be a serious complication; the precise etiology should be determined in order to provide appropriate therapy. We report two patients in whom profuse diarrhea was associated with cryptosporidium infections. The importance of clinicians and pathologists being aware of the complication in this clinical setting and the use of appropriate techniques for the isolation and identification of the microorganism are emphasized.

Adolescent↗

A histopathologic study of gastric and small intestinal graft-versus-host disease following allogeneic bone marrow transplantation.

Twenty-two stomach and 14 small intestinal biopsy specimens from 24 allogeneic bone marrow transplant recipients were reviewed to evaluate the histopathologic changes of graft-versus-host disease (GVHD) in these organs. Associations between these results and clinical symptoms and other biopsy results were sought. In both organs, single epithelial cell necrosis was found to correlate with GVHD. Gastric GVHD was diagnosed in eight patients and small intestinal GVHD in four. Gastric GVHD was characterized by nausea, vomiting, and upper abdominal pain without diarrhea (the latter being present in only two patients), while all four of the patients with small intestinal GVHD had upper gastrointestinal symptoms and diarrhea. These symptoms correlated with concurrent rectal biopsy findings; pathologic alterations were seen in only one of six specimens from patients with gastric GVHD but in three of four with small intestinal GVHD. These findings suggest that stomach biopsy may be necessary to diagnose GVHD in patients with upper gastrointestinal symptoms but no diarrhea and normal rectal biopsy specimens. Diagnostic problems may arise in the early posttransplantation period, when the effects of cytoreductive therapy may simulate GVHD, and in patients with gastrointestinal cytomegalovirus infection, which may also produce changes identical to those of GVHD.

Adolescent↗

Mucosal pseudolipomatosis of the colon.

Twenty-four cases of a lesion characterized by unlined spaces in the colorectal lamina propria are presented. While lesions such as this have been reported previously as "lipomatosis" of the colon, histochemical and ultrastructural examination reveals that they are not, in fact, composed of adipocytes. It appears that they may be composed of gas trapped in the lamina propria. Because of their gross and microscopical similarity to fat, however, the term "pseudolipomatosis" is proposed.

Adult↗