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K J Lewin

Publications and source records attributed to K J Lewin.

At least 73 records · Page 4Linked to original sources
PubMed1988

Composite gastric carcinoma. Report of a tumor of the carcinoma-carcinoid spectrum.

A composite tumor of the gastric antrum composed of areas of adenocarcinoma and poorly differentiated carcinoid is described, with histochemical and immunohistochemical documentation of endocrine and nonendocrine differentiation. The neoplasm maintained a composite architecture both within the site of origin and in lymph node metastases. The adenocarcinoma displayed a predominantly tubular architecture with focal sheets of clear cells. The poorly differentiated carcinoid was argyrophilic, chromogranin immunoreactive, and focally serotonin immunoreactive, and contained keratin intermediate filaments in a distinctive distribution suggestive of endocrine differentiation. Among the tumors of the carcinoma-carcinoid spectrum, the composite tumor is less common than either carcinomas with interspersed endocrine cells or carcinoids with interspersed nonendocrine cells.

Adenocarcinoma↗
PubMed1988

Demonstration of estrogen receptors by monoclonal antibody in formalin-fixed breast tumors.

An immunohistochemical technique using a commercially available monoclonal antibody to the estrogen receptor in formalin-fixed breast tumors is described. The author's technique is compared to three other recently published techniques in 27 case studies. The authors' method using pronase enzyme pretreatment and alkaline phosphatase as the third antibody yielded the best results. Comparison with the standard dextran-coated charcoal cytosolic assay results from the cases selected yielded a 100% sensitivity and 89% specificity for the authors' technique. The advantages of the immunohistochemical method over the biochemical assay are discussed and clinical implications are suggested. A step-by-step procedure for the authors' technique follows the text.

Adult↗
PubMed1987

Direct in situ hybridization for rapid detection of cytomegalovirus in bronchoalveolar lavage.

Rapid detection of cytomegalovirus (CMV) from pulmonary specimens in immunosuppressed persons may provide an origin for pneumonia. In situ DNA hybridization has been effective for detection of CMV in otherwise nondiagnostic histologic material. Studies comparing bronchoalveolar lavage (BAL) with open-lung biopsy have shown the former to be superior in detecting most pulmonary pathogens affecting immunocompromised patients. Fifty consecutive BAL specimens were studied to compare direct in situ DNA hybridization, routine tissue culture, and conventional cytologic examination to assess the efficacy of the hybridization technic to rapidly detect CMV. Using tissue culture as the standard, a sensitivity of 90% (28 of 31) and specificity of 63% (12 of 19) were observed with the CMV probe. Discrepant results between the probe and tissue culture were present in ten cases. There were seven probe-positive, culture-negative cases, three of which had systemic CMV infection, including two patients with inclusions noted by conventional cytologic examination. Three probe-negative, culture-positive cases were found. In the authors' laboratory, the predictive value of a positive CMV probe is 80% (28 of 35). In contrast to the probe, conventional cytologic examination revealed CMV inclusions in only 23% (7 of 31) of the culture-positive cases. An average of 21 days was required for CMV cultures to become positive; probe results were available within 24 hours. The authors conclude direct in situ DNA hybridization is a useful rapid method for the detection of CMV in BAL specimens submitted for cytologic examination.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Gangliocytic paraganglioma associated with duodenal adenocarcinoma. Case report with immunohistochemical evaluation.

We present the first reported case (to our knowledge) of duodenal gangliocytic paraganglioma (GPG) to be associated with an underlying invasive adenocarcinoma. The patient, a 71-year-old man, presented with epigastric tenderness and was found to have metastatic adenocarcinoma in two regional lymph nodes. Immunohistochemical evaluation of the GPG demonstrated positive staining for gastrin, glial-fibrillary acidic protein, glucagon, neuron-specific enolase, pancreatic polypeptide, S100 protein, somatostatin, and substance P. The clinical, pathologic, and immunohistochemical features of GPG are discussed, with a review of the literature.

Adenocarcinoma↗
PubMed1986

Long-term total intraperitoneal nutrition in a rabbit model.

Total intraperitoneal (IP) nutrition was studied in a rabbit model. A mixture of 10% dextrose, 2% amino acids, and 3% lipids was continuously administered to 28 rabbits as their sole nutritional source for 21 days. Twenty rabbits received the solution via IP catheters; 8 of these underwent 50% small bowel resection (SBR) prior to IP infusion. As controls, 8 rabbits were administered the same solution intravenously (IV-TPN). Survival was 75% in both experimental and control groups. Weight gain was similar in IV- and IP-infused rabbits after 21 days. No significant decrease in body weight or changes in blood chemistry occurred after 50% SBR. A mild chemical peritonitis was seen with IP nutrition which resolved after discontinuing the infusions. Biochemical and histologic liver toxicity was more severe in the IV controls than the IP-infused rabbits. We conclude total calorie support can be delivered thorough the peritoneal cavity on a long-term basis; 50% SBR minimally affects IP absorption of nutrients; and the liver dysfunction seen after IV-nutrition is less severe with IP nutrition.

Animals↗
PubMed1986

Endocrine and tumor differentiation markers in poorly differentiated small-cell carcinoids of the cervix and vagina.

Immunoreactivity for endocrine peptides (serotonin, gastrin, somatostatin, insulin, corticotropin, calcitonin, neurotensin, vasoactive intestinal peptide, and bombesin), cytoskeletal proteins (high and low molecular weight keratins), and tumor differentiation markers (chromogranin, neuron-specific enolase, carcinoembryonic antigen, S100 protein, and Grimelius stain) was sought on nine cervical and one vaginal poorly differentiated small-cell carcinoids. Dense-core secretory granules were ultrastructurally identified in all cases (seven of ten) in which tissue was available for electron microscopy. Immunoreactivity for endocrine secretory products was rarely noted, and only in a minority cell population (serotonin in two of ten). The majority of the tumors exhibited immunoreactivity for low molecular weight keratin (AE1/AE3 in eight of ten; CAM 5.2 in seven of nine), and three of ten tumors focally expressed high molecular weight keratin. Among the markers of neuroendocrine differentiation, neurospecific enolase was more frequently expressed (ten of ten) than chromogranin (five of ten) or argyrophilia (three of ten). Carcinoembryonic antigen was present in eight of ten tumors. S100 protein was absent in all cases. In summary, poorly differentiated small-cell carcinoids of the lower female genital tract, similarly to other small-cell endocrine tumors, occasionally exhibit focal glandular and squamoid differentiation, and only relatively infrequently or focally express immunohistochemically detectable endocrine secretory products, chromogranin, and argyrophilia.

Antigens, Neoplasm↗
PubMed1985

Clinical and pathologic findings of the liver in the acquired immune deficiency syndrome (AIDS).

Clinical data and histologic sections of the liver, including immunohistochemical studies for hepatitis B surface and core antigens, were reviewed in 42 autopsy cases of the acquired immune deficiency syndrome (AIDS). Hepatomegaly, elevation of serum transaminases, and mild elevation of alkaline phosphatase were commonly observed clinical and biochemical abnormalities. Mildly elevated alkaline phosphatase and normal bilirubin levels were present in patients with Mycobacterium avium-intracellulare (MAI) infection, cytomegalovirus (CMV) infection, and Kaposi's sarcoma (KS). Histologic sections demonstrated liver involvement by MAI in eight cases; KS in six cases; cryptococcus in three cases; and CMV in two cases. One case of MAI infection was associated with marked central vein sclerosis, a finding previously unreported. Thirty-two (76%) of 42 cases had serologic or pathologic evidence of hepatitis exposure. Two patients had histologic evidence of chronic active hepatitis. The pathologic processes involving the liver appeared to be secondary to the infections and neoplasms for which this population is susceptible and did not significantly contribute to morbidity or mortality. No findings specific or pathognomic for AIDS were identified in the liver.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Immunoperoxidase study of lymphomas. Comparison of a one-step frozen section technic with indirect methods on paraffin sections.

Fifty cases of non-Hodgkin's lymphoma (15 nodular and 35 diffuse) were studied to determine the sensitivity, specificity, and ease of several different immunoperoxidase methods. The methods included a rapid, simple one-step immunoperoxidase procedure on frozen sections compared with indirect immunoperoxidase technics on paraffin sections. The frozen-section immunoperoxidase technic stained 15 of 15 nodular lymphomas and 24 of 35 diffuse lymphomas for monoclonal light chain. The majority of the diffuse lymphomas that did not stain for light chains were morphologically and immunohistochemically consistent with T-cell lymphomas. The indirect method on B-5 and formalin-fixed tissues only rarely displayed monoclonal staining for nonplasmacytoid small cell lymphomas but did stain some large cell lymphomas and a majority of plasmacytoid lymphomas for monoclonal light chain. The frozen section technic presented in this report is sufficiently sensitive and reliable to detect immunoglobulins in any morphologic subtype of B-cell lymphoma, whereas paraffin-embedded tissues have only limited application.

Avidin↗
PubMed1985

Disseminated bombesin-producing carcinoid tumor of pulmonary origin.

A case of a bombesin-producing carcinoid tumor of the lung is reported. Morphologically, the tumor was a typical argentaffinic carcinoid which contained bombesin as demonstrated by diffuse granular cytoplasmic staining using the immunoperoxidase method. Electron microscopy revealed dense-core granules measuring 100-150 nm, consistent with bombesin-containing endocrine cells. In man, bombesin-producing endocrine cells are found predominantly in the bronchopulmonary tree and scattered throughout the intestinal tract. The majority of previously reported bombesin-producing tumors have arisen, as in this case, in the lung; thus the demonstration of bombesin-like immunoreactivity in a widely metastatic tumor should direct the search for a primary lesion to the lung. Bombesin is known to have gastrin-releasing hormone activity. The presence of a gastric ulcer in the present patient raised the possibility of a bombesin-mediated Zollinger-Ellison-like syndrome, an association not previously described.

Aged↗
PubMed1985

Colonic lymphoma in ulcerative colitis.

Only rarely has lymphoma been associated with ulcerative colitis. We report a 25-year-old man with an 8-year history of ulcerative colitis, who developed diffuse large cell lymphoma (histiocytic) of the colon. We review 17 previously reported cases and discuss the risk of lymphoma, diagnostic clues, prognosis, and the evidence for a relationship between ulcerative colitis and lymphoma.

Adult↗
PubMed1985

Gastrointestinal lymphomas. Immunohistochemical studies on the cell of origin.

The classification of primary malignant lymphomas of the gastrointestinal tract by their cell of origin has been a subject of great controversy in recent years, with the proportion of histologic subtypes varying substantially in different published series. Much of this controversy was initially due to the widely recognized inherent difficulty of classifying lymphomas based on routine histologic sections alone. However, the advent of immunohistochemical techniques has also yielded disparate results. Particularly contentious has been the notion of true histiocytic lymphomas, which some investigators have claimed to be relatively frequent in the gastrointestinal tract, whereas others doubt whether they exist at all. We present here a classification of 25 gastrointestinal lymphomas seen in the surgical pathology services of UCLA Hospital and Stanford University Medical Center. Unlike all previously reported series, we have utilized frozen tissue sections for the performance of immunohistochemical studies, which we and others have found to be far more reliable than the use of formalin-fixed, paraffin-embedded tissues, particularly in detecting monoclonal surface staining of immunoglobulin light- and heavy-chain markers. We find that this technique lessens the likelihood of overinterpreting the stains for histiocyte markers (alpha 1-antitrypsin and lysozyme), which are often difficult to read owing to strong positive staining of benign reactive histiocytes within the tumor. Utilizing these techniques, we have been able to classify definitely 21 of our 25 lymphomas (84%) as of B-cell origin, whereas none appeared to be histiocytic. We conclude that true histiocytic lymphomas of the gastrointestinal tract must be very rare, and we recommend the routine use of frozen tissue sections for more accurate classification of these interesting lesions.

Adult↗
PubMed1985

Chronic active hepatitis of hepatitis B and non-A, non-B etiology. Immunohistochemical localization of hepatitis B core antigen in a series of needle biopsies.

Hepatitis B core antigen (HBcAg) was immunohistochemically demonstrated in 19 of 30 needle liver biopsies (63%) of chronic active hepatitis (CAH) from 15 of 24 patients (63%) whose serum contained hepatitis B surface antigen (HBsAg). The percentage of hepatocytes with nuclear and/or cytoplasmic immunoreactivity was quantified in each biopsy specimen, and these percentages were then compared with the amount of HBsAg and the degree of inflammation within the biopsy specimen. The percentage of HBcAg-positive hepatocytes in a biopsy specimen was greatest in those specimens that contained the most HBsAg, although this finding was not statistically significant. The percentage of HBcAg-positive hepatocytes was greatest in those specimens having the least inflammatory activity, and this was statistically significant (P less than .01). Also, the percentage of biopsy specimens containing HBcAg was increased in those groups with lesser inflammatory activity (P less than .01). By staining for both HBcAg and HBsAg, the detection rate of hepatitis B (HB)-related antigens rose to 27 of 30 biopsies (90%) in 22 of 24 patients (92%).

Biopsy, Needle↗