The detection of a viral interfering substance in the Shope papilloma and the Vx7 and Vx2 carcinomas.

In vivo assay of Shope papilloma protein extract and in vitro assay of extracts from Shope papilloma, Vx7 and Vx2 carcinomas showed strong interferon-like activity in the papilloma and moderate activity in the carcinomas. The interpretation is that the presence of viral nucleic acid in all three tumors stimulated the production of this substance even though fluorescent antibody studies reveal the protein coat only in the papilloma and Vx7.

Alterations in protein and nucleic acid metabolism of lymphoma 6C3HED-og cells in mice given guinea pig serum.

Lymphoma 6C3HED-OG cells, known from previous work to be susceptible to the effects of guinea pig serum in vivo and dependent upon extrinsic asparagine for protein synthesis and growth in vitro, remained for the most part morphologically intact and countable in the electronic cell counter following exposures of 1 and 2 hr to the effects of heated (56 degrees C, 30 min) guinea pig serum injected into the peritoneal cavities of mice in which the lymphoma cells were growing rapidly; after exposures of 4 and 6 hr the bulk of the -OG cells remained still intact and countable in the cell counter, though by this time a small proportion of them (5 to 12%) proved stainable with eosin in wet preparations) hence were presumably nonviable. After 12, 16, and 24 hr of exposure, however, the bulk of the -OG cells were either lysed or fragmented, to the extent that they did not register in the cell counter. Morphologic studies of the cells exposed 16 and 24 hr to the effects of heated guinea pig serum in vivo, disclosed that most of the cells then remaining were either frankly necrotic or greatly altered otherwise, marked vacuolation of the cytoplasm being the most conspicuous alteration in cells not yet obviously necrotic. Long before the bulk of the Lymphoma 6C3HED-OG cells had become conspicuously changed morphologically following exposure to the effects of heated guinea pig serum in vivo, they manifested striking alterations in protein metabolism, as was disclosed by "pulse" studies with radioactive valine. For example, the protein metabolism of -OG cells, as measured by their incorporation of L-valine-C(14), was sharply curtailed following 15 min of exposure to heated guinea pig serum in vivo, as compared with valine incorporation by cells labeled immediately after exposure to the guinea pig serum. Following exposure to heated guinea pig serum during 60 min, -OG cells incorporated less than half as much L-valine-C(14) as did cells labeled immediately after exposure, and the incorporation of L-valine-C(14) was still less after 120 min of exposure. By contrast, Lymphoma -RG1 cells, known from previous work to be wholly insusceptible to the effects of guinea pig serum in vivo and independent of need for extrinsic asparagine for protein synthesis and growth in vitro, showed no curtailment whatever of protein synthesis following exposures to the effects of heated guinea pig serum in vivo during periods of 15, 60, and 120 min. Reasons are given for considering the prompt inhibition of protein synthesis in the asparagine-dependent -OG cells a direct result of asparagine-deprivation induced in vivo by the injected guinea pig serum, the L-asparaginase of which presumably converted the available L-asparagine of the host to L-aspartic acid that was not taken up by the -OG cells. The synthesis of deoxyribonucleic acid by Lymphoma 6C3HED-OG cells, as measured by the incorporation of thymidme-H(3), determined with the aid of liquid scintillation counting and autoradiography, was also altered by exposure of the lymphoma cells to the effects of heated guinea pig serum in vivo, though not during exposures of 15 and 60 min; only after an exposure of 120 min did the population of -OG cells incorporate notably less thymidine-H(3) than did control populations, though after 240 min of exposure the -OG cells incorporated less than one-fifth as much tritiated thymidineas had -OG cells exposed to heated guinea pig serum for 60 min or to heated horse serum for periods up to 240 min. Autoradiographs indicated that DNA synthesis by -OG cells normally proceeds at an intense level that leads to some 60% of these cells being heavily labeled in autoradiographs at any given time; after exposure to the effects of heated guinea pig serum during 2 and 4 hr in vivo, however, the lymphoma cells lost their ability to incorporate enough tritiated thymidine to become heavily labeled, but approximately the same proportion of them (56 to 58%) retained their ability to incorporate sufficient tritiated thymidine to become lightly labeled. The possibility is considered that the inhibition of DNA synthesis in the asparagine-dependent -OG cells exposed to the effects of heated guinea pig serum in vivo may be secondary to the previously manifest inhibition of protein synthesis. Further, in tests of ribonucleic acid metabolism of Lymphoma 6C3HED-OG cells after exposure to the effects of heated guinea pig serum in vivo during periods of 15, 60, 120, and 240 min, the findings indicated that the ability of the lymphoma cells to synthesize RNA, as measured by their capacity to incorporate uridine-5-H(3), remained unaltered during the exposures of 15, 60, and 120 min, but was substantially reduced following 240 min of exposure. The findings are considered in relation to the probability, disclosed in part by previous studies, that heated guinea pig serum brings about its effects upon Lymphoma 6C3HED-OG cells in vivo by providing active L-asparaginase in large amounts, which presumably converts the available (extracellular) asparagine of the host to aspartic acid, the latter not being taken up by the lymphoma cells in vivo or in vitro. Hence it seems likely that heated guinea pig serum in this way brings about a state of asparagine deprivation that is responsible for the sequential metabolic and morphologic alterations that become manifest in asparagine-dependent Lymphoma 6C3HED-OG cells following their exposure to the effects of guinea pig serum in vivo, as here described.

Prevalence of esophageal dysmotility in a cohort of patients with esophageal biopsies consistent with eosinophilic esophagitis.

Eosinophilic esophagitis (EoE) is increasingly being diagnosed in adults presenting with dysphagia, food impactions, and chest pain. Studies to date provide conflicting data on the association of EoE and esophageal dysmotility. The objective of this study was to evaluate the prevalence of esophageal dysmotility in a cohort of patients with biopsies consistent with EoE at a military treatment facility. This is a prospective evaluation of consecutively identified patients at our institution diagnosed with EoE from March 1, 2005 to June 1, 2007. Thirty-two patients with biopsies consistent with EoE completed a symptom survey and 30 underwent esophageal manometry. The majority of EoE patients (23/30, 77%) had a normal end-expiratory lower esophageal sphincter (LES) pressure (normal range 10-35), whereas six patients had a low-normal LES pressure (6-9 mm Hg) and one patient had a decreased LES pressure (<5 mm Hg). Five patients (15.6%) were diagnosed with a nonspecific esophageal motor disorder (NSEMD). Two patients had high mean esophageal amplitude contractions >180 mm Hg (188 mm Hg, 209 mm Hg). No patient was diagnosed with nutcracker esophagus or diffuse esophageal spasm. Patients with and without NSEMD reported a similar degree of swallowing difficulty, heartburn, belching, chest pain, regurgitation, symptoms at night, and total symptom score. Likewise, eosinophil count on mucosal biopsy was similar between patients with and without a NSEMD. In this cohort, we found the prevalence of an NSEMD to be similar to that of a 10% prevalence found in a gastroesophageal reflux population.

Surveillance, epidemiology, and end results lung cancer data applied to the World Health Organization's classifications of lung tumors.

Less than 1% of the lung cancer cases from the Surveillance, Epidemiology, and End Results (SEER) Program changed categories as a result of the World Health Organization's revision of histologic classifications of lung tumors. Of the 28,119 microscopically proved lung cancers reported to SEER in 1977-79, 32% were squamous cell carcinoma, 16% were small cell and/or oat cell carcinoma, 27% were adenocarcinoma, 8% were large cell carcinoma, and 5% were other specified types. A further 12% (approximately 3,500 cases) were reported with such nonspecific terms as bronchogenic carcinoma, carcinoma of the lung, and undifferentiated or anaplastic carcinoma. The magnitude of the use of these nonspecific terms showed the need for greater precision in reporting and recording data.

Body iron stores and risk of colonic neoplasia.

BACKGROUND: Body iron stores and dietary iron intake have both been shown to be positively associated with subsequent risk of colon cancer. This finding comes from a cohort study involving 14,000 men, but the positive association occurred in only 12 cases. PURPOSE: We performed a case-control study of 264 men and 98 women to test for an association between serum ferritin levels and the presence of adenoma of the colon that would be independent of other known risk factors. METHODS: Serum ferritin levels were determined in this study from sera, frozen at -80 degrees C for 5-8 years, that had been originally obtained between 1984-1987 at the Walter Reed Army Medical Center from adult male and postmenopausal female patients undergoing routine colonoscopic examination and previously enrolled in a case-control study that assessed the potential dietary and environmental risk factors for colonic neoplasia. The presence of fecal occult blood in the stool or the suggestion of colonic polyps seen on barium enema defined eligibility for the study. Patients with known preexisting colonic disease were excluded. Eligible patients had their blood drawn and serum prepared. Following colonoscopy and histologic review, the patients were classified into three groups: normal (without neoplastic disease), 159 subjects; adenoma, 145 subjects; and colon cancer, 29 subjects. Body iron stores were determined by measuring serum ferritin levels by a competitive-binding radiometric immunoassay. Ferritin levels categorized into quintiles for adenoma were defined. Crude and adjusted odds ratios (ORadj) with 95% confidence intervals (CIs) for cancer and adenoma related to ferritin were calculated, controlling for known or suspected risk factors including sex, age, race, body mass index, family history, tobacco use, and alcohol consumption. RESULTS: Statistically significant associations of adenoma risk were seen in the third ([ORadj] = 3.8; 95% CI = 1.5-9.5) and fourth (ORadj = 5.1; 95% CI = 2.0-12.7) quintiles of ferritin relative to the first quintile, for smoking history (ORadj = 2.4; 95% CI = 1.3-4.3), for male sex (ORadj = 1.9; 95% CI = 1.0-3.7), and for family history of polyps or cancer (ORadj = 1.8; 95% CI = 1.0-3.4). From a second set of analyses that excluded 36 patients with serum ferritin of greater than or equal to 399 ng/mL, the greatest effect of ferritin on adenoma risk by anatomic subsite was seen in the right colon. CONCLUSION: The apparent dose-response for serum ferritin level and adenoma risk suggest that exposure to iron may be related to adenoma formation.

Inverted hyperplastic polyps of the colon.

An unusual form of hyperplastic polyp of the colon is described in which endophytic growth can simulate adenoma or carcinoma by penetration of the muscularis mucosae and a complex epithelial growth pattern. These lesions differ clinically from exophytic hyperplastic polyps by being more frequent on the right side than in the left colon and being relatively more common in women.

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.

Gastrointestinal stromal tumors in the appendix: a clinicopathologic and immunohistochemical study of four cases.

Mesenchymal tumors of the appendix are very rare, and specific stromal tumors (i.e., gastrointestinal stromal tumors, GISTs) have not been reported in this location to date. Four GISTs were identified in the review of primary mesenchymal tumors of the appendix from the files of the Armed Forces Institute of Pathology from 1970 to 1998. There were also one benign schwannoma, one diffuse neurofibroma with neurofibromatosis 1, one leiomyosarcoma in a child with HIV infection, and one inflammatory fibroid polyp. The four appendiceal GISTs occurred in adult males 56-72 years of age (mean 63 years). Two tumors occurred in patients who had surgery for appendicitis-like symptoms: one was an incidental finding during surgery for a malignant gastric epithelioid GIST and one was an incidental autopsy finding. Only one of the two appendices operated for symptoms had acute inflammation, and a polypoid GIST projected outward from the proximal part of appendix. Three tumors were partially obliterating nodules, eccentrically expanding the appendiceal wall. All four were spindle cell tumors, and three of them contained extracellular collagen globules (skeinoid fibers); none had atypia or mitotic activity (<1/50 high power fields). Immunohistochemically, two tumors studied were positive for CD117 (KIT), and two were positive for CD34. The tumors were negative for alpha-smooth muscle actin and S-100 protein. Follow-up revealed death from cardiovascular disease in one case (4 years after appendectomy) and liver failure because of malignant gastric epithelioid GIST metastatic to liver in another case 15 years after the appendectomy. This report documents the rare occurrence of CD117-positive GISTs as primary appendiceal tumors.

Ganglioneuromas of the gastrointestinal tract. Relation to Von Recklinghausen disease and other multiple tumor syndromes.

We studied 43 patients with ganglioneuromas of the gastrointestinal tract accessioned at the Armed Forces Institute of Pathology (AFIP) from 1940 to 1990 in order to determine their relation to von Recklinghausen's disease and other multiple tumor syndromes. They fell into three groups: polypoid ganglioneuroma (28 patients); ganglioneuromatous polyposis (7 patients); and diffuse ganglioneuromatosis (8 patients). Follow-up (1-24 years, average 8 years) for 16 of 28 patients with polypoid ganglioneuroma showed that none of these patients developed von Recklinghausen's disease or evidence or multiple tumor syndromes. Three of seven patients with ganglioneuromatous polyposis were alive and well but were reported to have multiple cutaneous lipomas and one reported a family history of multiple intestinal polyps. For seven of eight patients, diffuse ganglioneuromatosis was associated with other tumors, namely multiple endocrine neoplasia type IIb, multiple ganglioneuromas and neurofibromas limited to the gastrointestinal tract, von Recklinghausen's disease and neurogenic sarcoma. We conclude that the solitary polypoid ganglioneuroma of the gastrointestinal tract is not associated with the subsequent development of von Recklinghausen's disease or multiple endocrine neoplasia. All three forms of gastrointestinal ganglioneuromatous disease appear to be largely centered in the colon and rectum, unlike neurofibromas and neurofibromatosis, which, in our experience, occur more commonly in the small intestine and stomach.

Schwannomas in the colon and rectum: a clinicopathologic and immunohistochemical study of 20 cases.

Schwannomas of the colon and rectum are uncommon and incompletely characterized tumors, and only a small number of cases have been reported. This study was undertaken to determine the clinicopathologic profile of such tumors. A total of 20 colorectal schwannomas were identified and analyzed in a review of 600 mesenchymal tumors of the colon and rectum from the files of the Armed Forces Institute of Pathology. The schwannomas occurred equally in men (n = 9) and women (n = 11) in a wide age range (18-87 years; median age 65 years). The most common location was cecum (n = 7), followed by sigmoid and rectosigmoid (n = 6), transverse colon (n = 3), descending colon (n = 2), and rectum (n = 1); the location of one tumor had not been specified. The tumors commonly presented as polypoid intraluminal lesions, often with mucosal ulceration. Rectal bleeding, colonic obstruction, and abdominal pain were the most common presenting symptoms. The most common histologic variant (n = 15) was a spindle cell schwannoma with a trabecular pattern and vague or no Verocay bodies. These tumors ranged from 0.5 to 5.5 cm in diameter. A lymphoid cuff with germinal centers typically surrounded these tumors and focal nuclear atypia was often present, but mitotic activity never exceeded 5 per 50 HPF. All four epithelioid schwannomas occurred in the descending colon or sigmoid, three of them as small submucosal tumors. There was one plexiform schwannoma in the sigmoid composed of multiple nodules of prominently palisading schwann cells similar to those seen in conventional soft tissue schwannomas. All tumors studied were strongly positive for S-100 protein and also for low affinity nerve growth factor receptor (p75), collagen IV, and GFAP. Three tumors had CD34-positive cells, but all were negative for CD117 (KIT), neurofilament proteins, smooth muscle actin, and desmin. The percentage of MIB-1-positive cells was usually less than 1% and never higher than 3%. Colorectal schwannomas behaved in a benign fashion with no evidence of aggressive behavior or connection with neurofibromatosis 1 or 2, based on follow-up information on 18 patients.

Localized vasculitis of the gastrointestinal tract.

We studied the clinical and pathologic findings of 63 patients with localized vasculitis of the gastrointestinal tract, including 35 partial bowel resections, 14 cholecystectomies, five partial pancreatectomies, six appendectomies, one omentectomy, one gastrectomy, and one esophagectomy. Vasculitis was classified histologically as polyarteritis (n = 33), phlebitis (n = 12), Churg-Strauss angiitis (n = 8), small-vessel vasculitis (n = 6), Buerger's disease (n = 2), and giant-cell arteritis (n = 1). Nineteen of 33 cases of polyarteritis affected the small bowel or gallbladder, and nine patients with polyarteritis had elevated serum antinuclear antibodies or rheumatoid factor. Eight of 12 cases of phlebitis affected the right colon; there were giant cells in four of these 12 cases, a history of medication use in seven of eight cases, and no evidence of serum autoantibodies. Short-term follow-up (mean, 5 years) demonstrated that systemic disease developed in six of 23 patients with polyarteritis (four of whom had elevated serum rheumatoid factor or antinuclear antibodies), the patient with giant-cell arteritis, and one of two patients with Buerger's disease. Systemic vasculitis did not develop in patients with other types of vasculitis. We conclude that patients with gastrointestinal phlebitis, polyarteritis without serum autoantibodies, and small-vessel vasculitis have a low short-term risk for the development of systemic disease.

Stromal tumors of the gastrointestinal tract: myogenic or neurogenic?

Because of the recent controversy over the histogenesis of gastrointestinal stromal tumors, 170 gastrointestinal tract tumors appearing to be of smooth muscle type with routine stains were studied immunohistochemically. Five percent were positive for S-100 ("neural") protein. These findings are compared with several recent studies. We conclude that only a small minority of gastrointestinal tract stromal tumors are neurogenic and that most are probably of smooth muscle type.

Gastrointestinal stromal tumors and leiomyosarcomas in the colon: a clinicopathologic, immunohistochemical, and molecular genetic study of 44 cases.

Gastrointestinal stromal tumors (GISTs), mesenchymal tumors largely specific for the gastrointestinal tract, have been well defined in the stomach and small intestine, but have not been extensively documented or contrasted with true smooth muscle tumors in the colon. This study was undertaken to determine the clinicopathologic features of GISTs of the colon, excluding the rectum, and to compare them with leiomyosarcomas (LMSs) of the same location. A total of 37 colonic GISTs and seven LMSs from the files of the Armed Forces Institute of Pathology and the Haartman Institute of the University of Helsinki were analyzed. The GISTs occurred predominantly in adults older than 50 years of age (median, 67 yrs), and most were histologically malignant; four small benign tumors (< or = 1 cm) were incidentally detected, and 10 others had minimal mitotic activity (five or fewer mitoses per 50 high-power fields). The colonic GISTs were typically transmural tumors with frequent intraluminal and outward bulging components. Histologically, they usually showed a spindle cell pattern (92%), whereas 8% were epithelioid. Most tumors (19 of 25) were positive for CD117 (KIT) and for CD34 (16 of 27); six tumors coexpressed alpha-smooth muscle actin and CD117; none showed desmin or S-100 protein. C-kit mutations in exon 11 were seen in 5 (36%) of 14 colonic GISTs. None of the patients with incidental small tumors had a recurrence, whereas 2 of 10 patients with tumors larger than 1 cm but minimal mitotic activity died of the disease with liver metastasis. Nearly all patients whose tumor was larger than 1 cm and showed more than five mitoses per 50 high-power fields died of disease; half had evidence of metastasis. LMSs were typically intraluminally bulging, polypoid masses that showed a histologic likeness to differentiated smooth muscle cells. They occurred in five men and two women with a median age of 61 years. Most LMSs were high-grade histologically and showed smooth muscle actin, desmin, or both. All were negative for CD34 and CD117 and lacked c-kit mutations. Five of the seven patients died of disease, and two had a long-term survival, despite high mitotic activity. These results show that KIT-positive GISTs are more common than LMSs of the colon, and these tumor groups have clinicopathologic differences that warrant their separation.

Esophageal stromal tumors: a clinicopathologic, immunohistochemical, and molecular genetic study of 17 cases and comparison with esophageal leiomyomas and leiomyosarcomas.

Although rare elsewhere in the gastrointestinal tract, leiomyomas (LMs) are the most common esophageal mesenchymal neoplasms. In contrast, gastrointestinal stromal tumors (GISTs) predominate in the stomach and intestines but have not been documented in the esophagus. This study was undertaken to determine the clinicopathologic features and frequency of esophageal GISTs compared with LMs and leiomyosarcomas (LMSs) of the esophagus. A total of 68 stromal/smooth muscle tumors from the Armed Forces Institute of Pathology and the Haartman Institute of University of Helsinki were reclassified by current histologic and immunohistochemical criteria. There were 17 GISTs, 48 LMs, and three LMSs. The esophageal GISTs occurred in 12 men and five women with a median age of 63 years (range, 49-75 years). All tumors were from the lowest third of the esophagus, and the most common complaint was dysphagia, whereas two tumors were detected incidentally. Histologically the tumors had an overall basophilic appearance and showed combinations of solid, myxoid, and perivascular collarlike patterns with a spindle cell histology in 13 patients and epithelioid histology in four patients. All tumors were positive for CD117 and for CD34, whereas two patients were also positive for alpha-smooth muscle actin (SMA) and three patients were positive for desmin. One patient showed a unique immunophenotype with coexpression of CD117, CD34, SMA, and desmin. Nine patients died of disease, including all who had a tumor larger than 10 cm, and also one patient whose tumor showed five mitoses per 50 high-power fields. In comparison, esophageal LMs (n = 48) occurred in a younger population (median age, 35 years) but, similar to the GIST group, men predominated (67%). All LMs were clinically indolent tumors with no tumor-related mortality. The LMs showed eosinophilic cytoplasm, and were positive for desmin and SMA, and negative for CD117 and CD34. All three LMSs were large high-grade tumors that showed muscle cell markers but no CD117. All patients died of disease. Esophageal GISTs showed mutations in exon 11 of c-kit as described previously in gastric and intestinal GISTs. The separation of GISTs from esophageal LMs is important diagnostically because the former group has a high risk of malignant behavior.

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.

Sclerosing mesenteritis, mesenteric panniculitis and mesenteric lipodystrophy: a single entity?

We reviewed 84 cases coded as mesenteric lipodystrophy (ML), mesenteric panniculitis (MP), or retractile mesenteritis and sclerosing mesenteritis (SM), grading fibrosis, inflammation, and fat necrosis, and evaluating clinical subgroups. There was no gender or racial predominance. Patient age range was 23-87 years (average 60). Patients most often presented with abdominal pain or a palpable mass. A history of trauma or surgery was present in four of 84 patients. The most common site of involvement was the small bowel mesentery as a single mass (58 of 84) with an average size of 10 cm, multiple masses (15 of 84), or diffuse mesenteric thickening (11 of 84). All patients had some degree of fibrosis, chronic inflammation, and fat necrosis. Although a few patients showed a sufficient prominence of fibrosis, inflammation, or fat necrosis to permit a separation into SM, MP, or ML, respectively, in most patients these three components were too mixed for a clear separation. The clinical, demographic, and gross features did not help in defining these three entities. Contributors diagnosed 12 as sarcoma. Of 39 patients followed beyond the postoperative period, none died of these lesions. We conclude that SM, MP, and ML appear to represent histologic variants of one clinical entity, and in most cases "sclerosing mesenteritis" is the most appropriate diagnostic term.

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.

Prognosis of gastrointestinal smooth-muscle (stromal) tumors: dependence on anatomic site.

Although the significance of various prognostic factors, such as tumor size and mitotic index (MI), has been well established for smooth-muscle tumors of the stomach, the significance of these factors in other sites is less well defined. We studied 1004 patients with gastrointestinal smooth-muscle tumors for whom vital status could be determined. The average MI and tumor size varied significantly among the five major sites examined: esophagus (53 cases), stomach (524 cases), small bowel 252 cases), colon/rectum (108 cases), and omentum/mesentery/peritoneum (67 cases). There was a significant difference in site-specific survival (p = 0.001), with 10-year survival varying between 50% and 70%. Multivariate analysis demonstrated tumor location (p = 0.0320), size (p = 0.0003), MI (p < 0.0001), and patient age (p < 0.0001) to each carry independent prognostic value. The significance of MI was highly site dependent. Separation of survival curves for the stomach, using a threshold for analysis of either 5 or 10 mitotic figures/50 high-power fields, was very good. In contrast, small-bowel tumors showed little separation between survival curves, regardless of whether a threshold of 1, 5, or 10 mitotic figures MF/50 high-power fields was used to distinguish groups. In no site were tumor size and MI alone sufficient to provide an accurate long-term prediction of prognosis. Although tumor location, size, MI, and age have independent value in predicting the prognosis of patients with gastrointestinal smooth-muscle tumors, better methods are still required to accurately predict clinical course.

Gastrointestinal stromal tumors, intramural leiomyomas, and leiomyosarcomas in the rectum and anus: a clinicopathologic, immunohistochemical, and molecular genetic study of 144 cases.

Gastrointestinal stromal tumors (GISTs), the specific KIT-positive mesenchymal tumors of the gastrointestinal tract, have been sporadically reported in the rectum, but there are few clinicopathologic series. In this study we analyzed the clinicopathologic features of 133 anorectal GISTs, 3 intramural leiomyomas (LMs), and 8 leiomyosarcomas (LMSs) from the files of the Armed Forces Institute of Pathology and the Haartman Institute of the University of Helsinki. Ninety-six GISTs were documented as KIT-positive and three additional ones as CD34-positive. Thirty-four tumors were included by their histologic similarity to KIT- or CD34-positive cases. GIST-specific c-kit gene mutations, mostly in exon 11, were documented in 18 of 29 cases (62%). The GISTs occurred in adults with the age range of 17-90 years (median 60 years) with a significant male predominance (71%). The tumors ranged from small asymptomatic intramural nodules to large masses that bulged into pelvis causing pain, rectal bleeding, or obstruction. They were mostly highly cellular spindle cell tumors; four tumors had an epithelioid morphology. The tumors coexpressed CD34 and KIT and were rarely positive for smooth muscle actin or desmin and never for S-100 protein. Seventy percent of patients with tumors >5 cm with more than 5 mitoses/50 high power fields (HPF) (n = 31) died of disease, whereas only one tumor <2 cm with <5 mitoses/50 HPF (n = 21) recurred and none caused death. Long latency was common between primary operation and recurrences and metastases; either one occurred in 60 of 111 patients with follow-up (54%). Distant metastases were in the liver, bones, and lungs. Three benign actin- and desmin-positive and KIT-negative intramural LMs, similar to those seen in the esophagus, were identified. There were eight LMSs, six of which formed a polypoid intraluminal mass and were actin-positive and KIT-negative. Despite high mitotic counts, only one LMS patient died of disease. A great majority of rectal smooth muscle and stromal tumors are GISTs, which have a spectrum from minimal indolent tumors to overt sarcomas. Intramural LMs are exceptional, and true LMSs are rare, and similar to colonic ones, often present as intraluminal polypoid masses that appear to have a better prognosis than GISTs with similar mitotic rates.

Association of mucinous tumors of the ovary and appendix. A clinicopathologic study of 25 cases.

Twenty-five patients with mucinous tumors of the ovary and appendix were studied. The average age of the patients was 52 years, and the ovarian and appendiceal tumors were discovered synchronously in all but two cases. The majority had either a pelvic mass or abdominal or pelvic pain. A high frequency of bilateral ovarian tumors (11/25), and right-sided predominance for the unilateral ovarian tumors (nine right, five left) were found. Four patients had ovarian mucinous carcinomas, 10 had mucinous tumors of low malignant potential, 10 had mucinous cystadenomas, and one had a mucinous cyst. Pseudomyxoma ovarii was present in 22 cases. Twenty-two of 24 appendices were grossly abnormal. There were six appendiceal mucinous adenocarcinomas, 10 mucinous tumors of uncertain malignant potential, seven mucinous cystadenomas, one hyperplastic polyp, and one mucocele. Twelve patients had ovarian and appendiceal tumors of similar malignant potential, nine had appendiceal tumors with more aggressive morphologic features than the corresponding ovarian tumor, and four had ovarian tumors with more aggressive morphologic features than the appendiceal tumor. Eighteen patients had peritoneal involvement by mucinous epithelium admixed with mucus (nine localized, nine diffuse). Immunoperoxidase reactions for four epithelial antigens in 15 cases showed complete concordance between ovarian and appendiceal lesions in only five cases and were not helpful in determining the site of origin of the peritoneal tumor. Our findings suggest an independent origin of the ovarian and appendiceal tumors in most cases and do not favor an origin in a single site. Furthermore, it is proposed that the peritoneal lesions may arise de novo as part of a multifocal neoplastic process.