Search PubMed⌕ Search

Biomedical subjects

L H Sobin

Publications and source records attributed to L H Sobin.

At least 109 records · Page 6Linked to original sources
PubMed1990

Carcinoids of the gastrointestinal tract.

Carcinoids are tumors of the diffuse endocrine system. They occur most frequently in the gastrointestinal tract. Although they are considered malignant, their biologic behavior varies. The radiologic and pathologic appearances of gastric, duodenal, ileal, appendiceal, and rectal carcinoids are presented.

Adolescent↗
PubMed1990

Radiology and the new TNM classification of tumors: the future.

The latest edition of the TNM classification of tumors reflects advances in radiologic imaging such as computed tomography, magnetic resonance imaging, and endosonography. These modalities have increased the significance of clinical staging by enabling staging to be performed earlier. Thus, therapeutic decisions can be made before rather than during surgery. This review highlights important changes in the new TNM classification, relates them to imaging modalities, and emphasizes the role of the radiologist in clinical staging.

Humans↗
PubMed1990

Carcinoid tumors of the duodenum. A clinicopathologic study of 99 cases.

Ninety-nine carcinoid tumors of the duodenum were studied. Seventy-seven patients were followed up for a mean period of 65 months, 20 tumors were autopsy findings, and two patients were unavailable for follow-up. Sixteen tumors (21%) produced metastases, all discovered initially; 3 patients (4%) died from metastatic disease (mean survival, 37 months postoperatively). Features associated with metastatic risk were involvement of muscularis propria, size greater than 2 cm, and the presence of mitotic figures. For 51 tumors, there was no correlation between immunohistochemical somatostatin and history of diarrhea, cholelithiasis, or diabetes mellitus (somatostatin syndrome). Five tumors were associated with Zollinger-Ellison syndrome and had immunohistochemical gastrin, but in the others there was no correlation between ulcer disease and gastrin positivity. Duodenal carcinoids are indolent, especially when small and localized to the submucosa. Immunohistochemical identification of somatostatin and gastrin has little clinical relevance.

Adult↗
PubMed1990

Risk and surveillance of individuals with colorectal polyps. Who Collaborating Centre for the Prevention of Colorectal Cancer.

Since colorectal adenomas are very probably the precursors of colorectal cancer, their detection and removal should result in a decrease in the incidence and mortality from colorectal cancer. Individuals who harbour an adenoma have a 30-50% probability of having additional adenomas at that time, and a 30% probability of having additional adenomas later. Adenomas are prevalent in countries where colorectal cancer is prevalent, about two-thirds of them being tubular and the rest tubulovillous or villous. The initial management of patients with an adenoma consists in searching by colonoscopy the entire colon and removing all additional polyps. Surgical resection is required wherever there is invasive cancer with adverse histological factors. Follow-up in most patients can be after 2-4 years, earlier follow-up being reserved for patients with numerous polyps or with a polyp that had been removed piecemeal. The results of ongoing trials should provide firm guidelines for follow-up and could also be used in mathematical modelling to examine alternative strategies and to help understand the evolving patterns of appearance of new polyps. Finally, a deeper understanding of the biology and inherited and acquired genetics will help identify individuals at risk for adenomas initially and at follow-up. Nutritional factors may also provide a basis for prevention of adenomas in high-risk countries. Many of these issues are being addressed in current research.

Adenoma↗
PubMed1990

Lymphoepithelial carcinoma of the stomach with Epstein-Barr virus demonstrated by polymerase chain reaction.

Epstein-Barr virus DNA was detected by polymerase chain reaction in a paraffin-embedded block of an undifferentiated lymphoepithelial gastric carcinoma but was absent in a poorly differentiated gastric adenocarcinoma which also had pronounced lymphoid stroma. This is the first report, to our knowledge, of a lymphoepithelial carcinoma of the stomach. The association with Epstein-Barr virus and the distinctive histologic appearance justify the separate classification of undifferentiated lymphoepithelial carcinomas of the stomach similar to those of the nasopharynx from adenocarcinomas with lymphoid stroma.

Adenocarcinoma↗
PubMed1990

Eroded polypoid hyperplasia of the rectosigmoid.

We studied histologic sections and clinical data from six patients with multiple rectosigmoid polyps that could not be readily classified. Features common to all were: 1) numerous polyps restricted to the rectosigmoid colon without evidence of polyposis or gastrointestinal disease elsewhere, 2) severe clinical symptoms mimicking inflammatory bowel disease, 3) no family history of polyposis or evidence of infection and 4) histology showing minimally inflamed polypoid hyperplastic mucosa with surface erosions or pseudomembranes. Three patients underwent colectomies; three showed a response to oral steroids. One had rectal prolapse. Although reminiscent of inflammatory cloacogenic polyps or solitary rectal ulcer syndrome, the polyps extended into the sigmoid colon, were quite numerous, and showed only mild smooth muscle insinuation in the lamina propria. Whether these lesions are due to occult prolapse or are an unusual manifestation of inflammatory bowel disease remains unclear.

Adult↗
PubMed1990

Carcinoembryonic antigen and carcinoids of the gastrointestinal tract.

We studied the prognostic significance of immunohistochemically localized carcinoembryonic antigen in 131 nonmetastasizing and 35 metastasizing gastrointestinal carcinoid tumors. The rate of positivity was lower with preabsorbed versus nonabsorbed polyclonal antiserum. Compared with generally used prognostic features (depth of invasion, tumor size, and mitotic rate) positivity for absorbed anticarcinoembryonic antigen was the most specific feature for metastatic tumors but was least sensitive. Although our results demonstrate that anticarcinoembryonic antigen, particularly when absorbed, is highly associated with metastatic disease, depth of invasion and tumor size are better predictors of behavior.

Adolescent↗
PubMed1990

Intra-abdominal fibromatosis. A pathologic analysis of 130 tumors with comparison of clinical subgroups.

We studied the clinical, gross, and histologic findings of 130 fibromatoses of the mesentery and other peritoneal sites. Seventeen patients had Gardner syndrome, 12 had prior abdominal surgery, and six had apparent estrogen elevation, including five pregnant or postpartum women and an alcoholic male with gynecomastia. The tumors were usually large and grossly circumscribed. Most often, they were located in the mesentery of the small bowel. They were multiple in 18 cases. Typical histologic features included a dense, collagenous stroma; prominent, dilated, thin-walled vessels; muscular hyperplasia of small arteries; keloidal change; myxoid change; and fibrous tissue insinuation into the muscularis propria of the bowel. Although mitoses were noted in many tumors, they were usually few in number. The gross and histologic features were similar in the clinical subgroups; however, keloidal change was seen less often in female patients. Less than half of the cases were initially correctly diagnosed. Most patients without Gardner syndrome were without recurrence at follow-up, even when the lesions had been incompletely excised.

Abdomen↗
PubMed1990

Correlation of nucleolar organizer regions and glandular dysplasia of the stomach and esophagus.

Forty-seven biopsies of gastric mucosa and Barrett esophagus from 32 patients were studied with the argyrophilic nucleolar organizer region method. Twenty-two biopsies were gastric and 25 esophageal. Four showed normal noninflamed mucosa, 14 reactive glandular changes, eight intestinal metaplasia without dysplasia, ten low grade dysplasia with intestinal metaplasia, and 11 high grade dysplasia. The mean number of nucleolar organizer regions was 14.9 for high grade dysplasia, 10.9 for low grade dysplasia, 8.5 for intestinal metaplasia without dysplasia, 6.7 for reactive changes, and 3.9 for normal mucosa. The difference between high grade dysplasia and the other groups was significant (P = 0.004). However, the difference between high and low grade dysplasia was not significant (P = 0.06), and there was an overlap between reactive and high grade dysplastic lesions. We conclude that although nucleolar organizer counts correlate with the degree of dysplasia, the technique is of limited practical use.

Barrett Esophagus↗
PubMed1990

Mesenteric fibromatosis. A follow-up study.

Eighty-two fibromatoses of the mesentery and other peritoneal sites were studied, with emphasis on features associated with recurrence. Twelve patients had Gardner's syndrome. Seventy-two tumors were completely excised at the time of surgery; 56 patients had no evidence of tumor recurrence (mean, 91 months), and in 16 patients tumors recurred (mean, 117 months of follow-up). Patients with Gardner's syndrome had a much higher risk of recurrence and death related to fibromatosis or surgery for fibromatosis than sporadic cases. There was a weaker association between recurrence and multiplicity. A history of trauma or estrogen exposure, size, mitotic activity, gross circumscription, and histologic features did not correlate with recurrence. Biopsies or partial resections were performed on 10 tumors (8 in patients without Gardner's syndrome and 2 in patients with Gardner's syndrome). The patients without Gardner's syndrome did well: 7 are alive without evidence of disease (mean, 72 months) and 1 died of lung carcinoma at 108 months. The 2 patients with Gardner's syndrome have persistent fibromatosis: 1 patient had recurrence in the abdominal wall at 103 months and 1 is alive at 72 months with intra-abdominal masses. We conclude that mesenteric fibromatosis is much more aggressive in patients with Gardner's syndrome than in patients without Gardner's syndrome, that pathologic features are not good predictors of aggressive behavior, and that complete surgical excision may not always be necessary.

Adolescent↗
PubMed1989

Cronkhite-Canada syndrome: radiologic features.

We report 6 cases of Cronkhite-Canada syndrome, analyze the patterns of involvement, and review the literature on this entity. There were 4 women and 2 men, with an average age of 58 years. The stomach was diseased diffusely in 5 and focally (distally) in 1. Small bowel polyps were detected in 4 patients. Patterns of involvement were classified as (a) innumerable small polyps carpeting large areas, (b) scattered varying-size polyps, and (c) sparse involvement with few small polyps. There was concordance of patterns between the stomach and colon in 5 of the 6 patients.

Adult↗
PubMed1989

Carcinoids of the duodenum. A histologic and immunohistochemical study of 65 tumors.

The light-microscopic and immunohistochemical characteristics of 65 duodenal carcinoids are presented. Most tumors showed a mixture of cribriform, insular, glandular, solid, and trabecular growth patterns. Eighty-five percent of the tumors were argyrophil and 15% argentaffin. The nonspecific neuroendocrine markers chromogranin, Leu-7, and neuron-specific enolase were positive in 97, 91, and 83% of tumors, respectively. Immunoreactivity for specific hormones/amines were as follows (percent positive tumors): somatostatin, 47%; N-gastrin, 56%; serotonin, 39%; calcitonin, 19%; insulin, 5%; pancreatic polypeptide, 3%; adrenal corticotropic hormone, 0%; glucagon, 0%. Sixty-eight percent had gastrin/cholecystokinin-like reactivity. Ten psammomatous tumors were located near the ampulla; eight were somatostatin positive, including two in patients with neurofibromatosis. One additional tumor in a patient with neurofibromatosis lacked psammoma bodies but elaborated somatostatin. Eight additional tumors in nonneurofibromatosis patients produced solely somatostatin. Duodenal carcinoids often elaborate more than one polypeptide hormone; those in the ampulla often elaborate somatostatin and have psammoma bodies.

Antigens, Differentiation↗
PubMed1989

The pathology of Cronkhite-Canada polyps. A comparison to juvenile polyposis.

We studied Cronkhite-Canada (CC) polyps from nine patients, and compared them to gastric and colonic juvenile and gastric hyperplastic polyps. The CC polyp is characterized by its broad sessile base, expanded edematous lamina propria, and cystic glands. Similar features are found in the lesions of juvenile polyposis and gastric hyperplastic polyps. The only reliable distinction between CC and colonic juvenile polyposis was the pedunculated growth of the latter; however, this feature did not hold for gastric lesions. Unlike CC polyps, juvenile polyps sometimes have areas of dysplasia, but this is not typical. Therefore the diagnosis of CC polps, especially when located in the stomach, requires the presence of the ectodermal changes characteristic of this syndrome.

Adenomatous Polyposis Coli↗
PubMed1989

Appendiceal carcinoids: correlation of histology and immunohistochemistry.

In order to compare histologic subtypes and endocrine profiles, immunohistochemical and silver stains were performed on 120 appendiceal carcinoids. Forty-three were predominantly insular; 21 were mixed insular, glandular, and trabecular; 33 were goblet cell; 17 were tubular; and five were clear cell carcinoids. Insular, mixed, and clear cell carcinoids were generally diffusely argentaffin and positive for chromogranin, neuron-specific enolase (NSE), and serotonin. Occasional tumors of insular or mixed patterns had scattered cells that stained weakly for glucagon, calcitonin, adrenocorticotrophic hormone (ACTH), somatostatin, cholecystokinin (CCK), human pancreatic polypeptide (HPP), or gastrin. Most had S-100-positive sustentacular cells. Less than half were positive for carcinoembryonic antigen (CEA). Many were cytokeratin-positive, but often focally. Goblet cell carcinoids contained few endocrine cells, but these were strongly argentaffin and positive for serotonin in nearly all, and positive for HPP in almost a third. Tubular carcinoids lacked argentaffinity and serotonin but were diffusely and strongly positive for glucagon. All goblet cell and tubular carcinoids were diffusely positive for CEA and cytokeratin. Somatostatin stained strongly in a single tumor, which had psammoma bodies and was in a patient with neurofibromatosis. In all groups, argentaffinity correlated with serotonin positivity, and argyrophilia with chromogranin positivity, although the latter was somewhat more sensitive. We conclude that among appendiceal carcinoids, the endocrine content varies according to histologic subtype.

Adrenocorticotropic Hormone↗