Signet Ring Cell Component Research Articles

Endometrial Adenocarcinoma With Signet Ring Cells

The presence of signet ring cells in a carcinoma within the uterine corpus strongly raises the possibility of a metastasis from a primary tumor in the breast, gastrointestinal tract, or elsewhere. Signet ring cells are extremely rare in primary endometrial adenocarcinomas with only a single prior case report. We report 2 cases of primary endometrial adenocarcinoma, one of mucinous and the other of endometrioid type, with a significant component of signet ring cells. One of the neoplasms arose within adenomyosis. In reporting these cases, we illustrate that the presence of signet ring cells does not preclude a primary endometrial adenocarcinoma.We discuss signet ring cells in the endometrium.

Frequent ALK rearrangement and TTF-1/p63 co-expression in lung adenocarcinoma with signet-ring cell component

Primary adenocarcinoma with signet-ring cell component (Ad-SRCC) of the lung has been well characterized clinicopathologically and histologically, but their genetics has rarely been investigated. A recent report suggesting an association between Ad-SRCC and EML4-ALK fusion prompted us to undertake a histological, immunohistochemical, and molecular analysis of 10 cases of primary Ad-SRCC identified out of 699 lung adenocarcinomas (1.4%). Most of the Ad-SRCCs showed characteristic architectural as well as cytological features including cohesive clustering of signet-ring cells, a solid/acinar growth pattern, and alveolar filling at the tumor periphery. Diffuse co-expression of TTF-1 and p63 was observed in half of the Ad-SRCCs, and this immunoprofile has not been recognized previously. Four Ad-SRCCs (40%) harbored ALK translocations detected by reverse-transcriptase polymerase chain reaction, fluorescence in situ hybridization, and immunohistochemistry. One new EML4-ALK fusion variant was identified. One ALK-rearranged tumor showed focal squamous differentiation. None of the present Ad-SRCCs had EGFR or KRAS mutations, regardless of ALK status. This study successfully utilized tumor histology alone to identify a subset of adenocarcinomas showing a high rate of ALK translocation. The characteristic histology, immunoprofile, frequent ALK translocation, and total lack of EGFR or KRAS mutations, may suggest that Ad-SRCC forms a histologically/molecularly coherent subgroup of adenocarcinoma.

Abstract 783: High microsatellite instability predicts good prognosis in intestinal type gastric cancers

Abstract A subset of gastric cancers shows high microsatellite instability (MSI-H). The reported clinicopathologic features of MSI-H gastric cancers are heterogeneous, and specific factors associated with prognosis have not been identified. We analyzed the clinicopathologic characteristics and prognostic factors in a large series (161 cases) of MSI-H gastric cancers, and compared the results to 315 cases of microsatellite stable or low MSI gastric cancers. The frequency of MSI-H gastric cancers was 9.0% (161/1786). MSI-H gastric cancers have distinct clinicopathologic features including female gender, older age, antral location, protruded gross type (Borrmann typeIand type II), well to moderate differentiation, intestinal type of Lauren classification, expanding type of Ming classification, non signet ring cell component, presence of mucinous component, moderate to severe lymphoid stromal reaction, and lower tumor stage. The MSI-H phenotype was associated with better prognosis (P = .044), and male gender (P = .035, HR: 0.23), intestinal/mixed type of Lauren classification (P <.001, HR: 0.09) and lower tumor stage (1 and 2) (P = .001, HR: 0.08) were independently favorable prognostic factors. With unique clinicopathologic features, the intestinal type MSI-H gastric cancers are associated with good prognosis and can be classified as a different subset of gastric cancers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 783.

Primary Signet-Ring Carcinoma (SRC) of the Lung: A Population-Based Epidemiologic Study of 262 Cases with Comparison to Adenocarcinoma of the Lung

The presence of signet-ring cell component has been described as a prominent feature of EML4-ALK positive non-small cell lung cancer. We investigated the clinicopathologic features and survival outcome of primary signet-ring carcinoma (SRC) of the lung with comparison to adenocarcinoma of the lung. Retrospective population-based analysis of histologically diagnosed primary SRC of the lung in the California Cancer Registry between 1989 and 2006 with comparison with adenocarcinoma of the lung. Two hundred sixty-two histologically diagnosed primary SRC of the lung were compared to 50,089 patients with lung adenocarcinoma. Patients with primary SRC of the lung were significantly younger than patients with adenocarcinoma, with a significantly higher proportion of poorly differentiated tumor and stage IV disease. There was no difference in the distribution of gender and ethnicity among patients with SRC when compared to patients with adenocarcinoma. Subset analysis of patients with available smoking status revealed never smokers comprised a significantly higher proportion of patients with SRC (30.8%) when compared to patients with adenocarcinoma (11.0%; p = 0.0013). Never smokers with SRC tended to be younger with a trend to improved survival (median age = 55 years, median overall survival [OS] = 8 months) than ever smokers with SRC (median age = 59 years, median OS = 4.5 months). Patients with SRC had decreased OS (versus adenocarcinoma; unadjusted hazard ratio = 1.507; 95% confidence interval: 1.326-1.714; p < 0.0001) and was an independent unfavorable prognostic factor by multivariate analysis (versus adenocarcinoma, hazard ratio 1.214, 95% confidence interval: 1.068-1.381; p = 0.0030). Primary SRC of the lung is a rare subtype of adenocarcinoma, carries a worse prognosis when compared to adenocarcinoma and shares many of the recently identified clinicopathologic characteristics ascribed to EML4-ALK positive non-small cell lung cancer.

Gastric leptomeningeal carcinomatosis: Multi-center retrospective analysis of 54 cases

To identify the clinical features and outcomes of infrequently reported leptomeningeal carcinomatosis (LMC) of gastric cancer. We analyzed 54 cases of cytologically confirmed gastric LMC at four institutions from 1994 to 2007. The male-to-female ratio was 32:22, and the patients ranged in age from 28 to 78 years (median, 48.5 years). The majority of patients had advanced disease at initial diagnosis of gastric cancer. The clinical or pathologic tumor, node and metastasis stage of the primary gastric cancer was IV in 38 patients (70%). The median interval from diagnosis of the primary malignancy to the diagnosis of LMC was 6.3 mo, ranging between 0 and 73.1 mo. Of the initial endoscopic findings for the 45 available patients, 23 (51%) of the patients were Bormann type III and 15 (33%) patients were Bormann type IV. Pathologically, 94% of cases proved to be poorly differentiated adenocarcinomas. Signet ring cell component was also observed in 40% of patients. Headache (85%) and nausea/vomiting (58%) were the most common presenting symptoms of LMC. A gadolinium-enhanced magnetic resonance imaging was conducted in 51 patients. Leptomeningeal enhancement was noted in 45 cases (82%). Intrathecal (IT) chemotherapy was administered to 36 patients-primarily methotrexate alone (61%), but also in combination with hydrocortisone/+/- Ara-C (39%). The median number of IT treatments was 7 (range, 1-18). Concomitant radiotherapy was administered to 18 patients, and concomitant chemotherapy to seven patients. Seventeen patients (46%) achieved cytological negative conversion. Median overall survival duration from the diagnosis of LMC was 6.7 wk (95% CI: 4.3-9.1 wk). In the univariate analysis of survival duration, hemoglobin, IT chemotherapy, and cytological negative conversion showed superior survival duration (P = 0.038, P = 0.010, and P = 0.002, respectively). However, in our multivariate analysis, only cytological negative conversion was predictive of relatively longer survival duration (3.6, 6.7 and 14.6 wk, P = 0.030, RR: 0.415, 95% CI: 0.188-0.918). Although these patients had a fatal clinical course, cytologic negative conversion by IT chemotherapy may improve survival.

Clinical significance of signet-ring cells in colorectal mucinous adenocarcinoma

Mucin occasionally accumulates intracellularly in colorectal mucinous adenocarcinomas, resulting in signet-ring cell morphology. In the current practice of pathology, there is no definitive rule on how to report a minor component of signet-ring cells in colorectal mucinous adenocarcinomas. We hypothesized that the absence of signet-ring cell component might have a favorable effect on survival of mucinous adenocarcinoma patients. To assess the biological characteristics of colorectal mucinous adenocarcinoma, we analyzed its clinicopathological features, microsatellite instability status, and survival outcomes and compared them with those of colorectal signet-ring cell carcinoma. A total of 266 consecutive colorectal mucinous adenocarcinoma patients and 65 signet-ring cell carcinoma patients were included. Mucinous adenocarcinomas, by comparison with signet-ring cell carcinomas, were characterized by development at an older age, less frequent vascular invasion and lymph node metastasis, and lower TNM stage at presentation. A total of 21 (22%) of 95 mucinous adenocarcinomas and 12 (19%) of 63 signet-ring cell carcinomas were high-frequency microsatellite instability. Patients with mucinous adenocarcinoma had significantly better survival than those with signet-ring cell carcinoma (P<0.0001) or than those with signet-ring cell carcinoma showing >50% extracellular mucin by volume (P<0.0001). In univariate analysis, absence of signet-ring cell component (P=0.0197), absence of vascular invasion, decreased invasion depth, no lymph node metastasis, and lower TNM stage had a favorable effect on survival of mucinous adenocarcinoma patients. Absence of vascular invasion, no lymph node metastasis, and lower TNM stage had a favorable effect on survival of signet-ring cell carcinoma patients. Multivariate analysis showed that higher TNM stage and T stage 4 were independent predictors of poor outcome in patients with mucinous adenocarcinoma. Our observations strongly suggest that pathologists should report the percentage of signet-ring cell component in colorectal mucinous adenocarcinomas and mucinous adenocarcinoma has different biologic behavior compared with signet-ring cell carcinoma.

Primary Ovarian Mucinous Tumors With Signet Ring Cells

The distinction between a primary ovarian mucinous carcinoma or even a borderline mucinous tumor and a metastatic mucinous carcinoma may be difficult. A constellation of clinical, gross pathologic and morphologic features is used in this distinction. One of the most important morphologic features suggesting a metastatic mucinous carcinoma in the ovary is the presence of signet ring cells; these are considered rare in primary ovarian mucinous tumors. In this study, we report 3 primary ovarian mucinous tumors with a component of signet ring cells. The tumors arose in patients aged 27, 55, and 60, were unilateral, confined to the ovary and stage IA. They ranged from 9 to 27 cm; 1 was grossly a multiloculated cystic lesion and 2 were cystic and solid. In one case, the neoplasm had the architecture of a mucinous adenofibroma but had frankly malignant cells lining glands and forming solid aggregates of cells. A second tumor also had the background of an adenofibroma. The third was mostly a mucinous cystadenoma. In one case, endometriosis was present in the same ovary; teratomatous elements were not identified in any case. Immunohistochemistry, performed in 2 cases, showed both to be diffusely positive with CK7 and CA19.9, including the signet ring cells. CK20 was positive in both cases (1 focal; 1 diffuse). Estrogen receptor and CA125 were diffusely positive and carcinoembryonic antigen and CDX2 focally positive in 1 case. Chromogranin and synaptophysin were negative. Investigations to exclude a gastrointestinal neoplasm in 2 cases were negative. Features favoring a primary rather than a metastatic neoplasm are unilateral tumor, low stage, background of adenofibroma or cystadenoma, associated endometriosis in 1 case and an absence of features which are characteristic of secondary mucinous carcinomas in the ovary, such as surface tumor deposits, a nodular growth pattern, and lymphovascular permeation. Immunohistochemistry is of limited value because of overlapping immunophenotype between a primary ovarian mucinous tumor and a metastasis from the stomach, pancreas, biliary tree, appendix, or colorectum, the most likely primary sites for a secondary exhibiting similar features. Our study illustrates that signet ring cells occur rarely in a primary ovarian mucinous tumor; even when conspicuous the features differ from those of the usual Krukenberg tumor. At least some cases of so-called primary Krukenberg tumor may be similar to our cases. However, the designation primary Krukenberg tumor should not be used as, apart from the signet ring cells, a resemblance to a "true" Krukenberg tumor of the secondary type is limited. The tumors should be classified according to the underlying background neoplasm with a notation concerning the signet ring cell component.

Folate and Vitamin B6 Intake and Risk of Colon Cancer in Relation to p53 Expression

Considerable evidence suggests that a low-folate diet increases the risk of colorectal cancer, although the results of a recent randomized trial indicate that folate supplementation may not reduce the risk of adenoma recurrence. In laboratory models, folate deficiency appears to induce p53 mutation. We immunohistochemically assayed p53 expression in paraffin-fixed colon cancer specimens in a large prospective cohort of women with 22 years of follow-up to examine the relationship of folate intake and intake of other one-carbon nutrients to risks by tumor p53 expression. A total of 399 incident colon cancers accessible for p53 expression were available. The effect of folate differed significantly according to p53 expression (P(heterogeneity) = .01). Compared with women reporting folate intake <200 microg/day, the multivariate relative risks (RRs) for p53-overexpressing (mutated) cancers were 0.54 (95% confidence interval [CI], 0.36-0.81) for women who consumed 200-299 microg/day, 0.42 (95% CI, 0.24-0.76) for women who consumed 300-399 microg/day, and 0.54 (95% CI, 0.35-0.83) for women who consumed >or=400 microg/day. In contrast, total folate intake had no influence on wild-type tumors (RR, 1.05; 95% CI, 0.73-1.51; comparing >or=400 with <200 microg/day). Similarly, high vitamin B(6) intake conferred a protective effect on p53-overexpressing cancers (top versus bottom quintile: RR, 0.57; 95% CI, 0.35-0.94; P(heterogeneity) = .01) but had no effect on p53 wild-type tumors. We found that low folate and vitamin B(6) intake was associated with an increased risk of p53-overexpressing colon cancers but not wild-type tumors.

Significance of Signet-Ring Cells in Patients with Colorectal Cancer

We performed a retrospective study to determine the pattern of metastases and overall outcome of patients with tumors exhibiting a component of signet-ring cells comprising < 50 percent of the tumor mass. Medical records of 753 patients with primary colorectal cancer were retrospectively studied. Patients who had tumors with < 50 percent signet-ring cells were classified as having a component of signet-ring cells. The outcome of patients with a component of signet-ring cells was compared to all patients with mucinous adenocarcinoma (defined as adenocarcinomas with > or = 50 percent mucin) to all patients with adenocarcinomas with a component of mucin (defined as adenocarcinomas with < 50 percent mucin) and to 100 randomly selected patients with adenocarcinomas lacking mucin or signet-ring cells. Five percent of patients had a component of signet-ring cells, 3 percent had mucinous adenocarcinoma, 9 percent had a component of mucinous adenocarcinoma, and 83 percent had adenocarcinoma lacking mucinous or signet components. Patients with a component of signet-ring cells and mucinous adenocarcinomas metastasized predominantly to the peritoneum/ovaries (75 and 56 percent of metastatic cases, respectively) and rarely to liver/lungs. The pattern of metastases of patients with adenocarcinoma without mucinous or signet components predominantly involved the liver/lungs and rarely the peritoneum/ovaries (12.5 percent). The pattern of metastases for patients with a component of mucinous adenocarcinoma was intermediate between mucinous adenocarcinoma and adenocarcinoma without mucin or signet-ring component. No differences in survival in Stage IV patients were seen among the four subgroups. Patients with a component of signet-ring cells cancers, similar to mucinous adenocarcinoma, have a predisposition to metastasize to the peritoneum/ovaries.

Ovarian Mucinous Tumors Associated With Mature Cystic Teratomas

Most primary ovarian mucinous tumors are of surface epithelial-stromal origin and exhibit diffuse expression of cytokeratin 7 (CK7) combined with variable expression of cytokeratin 20 (CK20); this immunoprofile distinguishes them from most lower gastrointestinal tract tumors secondarily involving the ovaries. The uncommon ovarian mucinous tumors of germ cell (teratomatous) origin have not been extensively evaluated to determine the utility of these markers and other markers of intestinal differentiation for distinguishing these tumors from metastatic gastrointestinal tract mucinous tumors. Immunohistochemical expression of CK7, CK20, CDX2, and villin was assessed in 44 ovarian mucinous tumors associated with a mature cystic teratoma. All cases lacked evidence of a nonovarian primary mucinous tumor. All mucinous tumors were unilateral; 6 cases had bilateral teratomas. All tumors displayed gastrointestinal-type mucinous differentiation, with epithelium that was commonly goblet cell-rich or hypermucinous; 21 were associated with pseudomyxoma ovarii and 3 of these had pseudomyxoma peritonei. Tumor architecture ranged from purely cystadenomatous (n=24), to proliferative (n=13), to carcinomatous (n=6); some tumors had admixtures of these patterns. One tumor had a goblet cell carcinoidlike pattern with pseudomyxoma ovarii. Three carcinomas had a signet ring cell component. Cystadenomatous tumors without pseudomyxoma ovarii (n=15) exhibited all possible CK7/CK20 coordinate expression profiles with nearly equal frequency. All proliferative tumors without pseudomyxoma ovarii (n=8) expressed CK7, most often in combination with CK20 expression. All cystadenomatous and proliferative tumors with pseudomyxoma ovarii (n=9 and n=5) were CK7-/CK20+. All carcinomatous tumors had pseudomyxoma ovarii; 3 were CK7-/CK20+, 2 were CK7+/CK20+, and 1 was CK7+/CK20-. The presence of pseudomyxoma ovarii was significantly associated with a CK7-/CK20+ profile (86% with pseudomyxoma ovarii vs. 13% without, P<0.0001), CDX2 positivity (79% vs. 0%, P<0.0001), and villin positivity (57% vs. 5%, P=0.0009). A subset of mucinous tumors associated with mature cystic teratomas exhibiting morphologic and immunohistochemical features of lower intestinal tract-type mucinous tumors may be teratomatous in origin. In practice, the more common diagnosis of secondary involvement by a lower intestinal tract mucinous tumor should be addressed in the pathology report and in subsequent clinical evaluation; interpretation as a true primary ovarian mucinous tumor of teratomatous origin can be considered as an alternative diagnosis when evaluation and follow-up fail to identify a nonovarian source of the mucinous tumor. Those tumors having CK7 expression with or without CK20 expression may be derived from upper gastrointestinal tract-type or sinonasal-type teratomatous elements but could be independent tumors of surface epithelial-stromal origin.

Correlation of Pathologic Features With CpG Island Methylator Phenotype (CIMP) by Quantitative DNA Methylation Analysis in Colorectal Carcinoma

Extensive gene promoter methylation in colorectal carcinoma has been termed the CpG island methylator phenotype (CIMP). Previous studies on CIMP used primarily methylation-specific polymerase chain reaction (PCR), which, unfortunately, may detect low levels of methylation that has little or no biological significance. Utilizing quantitative real-time PCR (MethyLight), we measured DNA methylation in a panel of 5 CIMP-specific gene promoters (CACNA1G, CDKN2A (p16), CRABP1, MLH1, and NEUROG1) in 459 colorectal carcinomas obtained from 2 large prospective cohort studies. CIMP was defined as tumors that showed methylation in >or=4/5 promoters. CIMP was significantly associated with the presence of mucinous or signet ring cell morphology, marked Crohn's-like lymphoid reaction, tumor infiltrating lymphocytes, marked peritumoral lymphocytic reaction, tumor necrosis, tumor cell sheeting, and poor differentiation. All these features have previously been associated with microsatellite instability (MSI). Therefore, we divided the 459 colorectal carcinomas into 6 subtypes, namely, MSI-high (MSI-H)/CIMP, MSI-H/non-CIMP, MSI-low (MSI-L)/CIMP, MSI-L/non-CIMP, microsatellite stable/CIMP, and micro satellite sstable/non-CIMP. Compared with MSI-H/non-CIMP, MSI-H/CIMP was associated with marked tumor infiltrating lymphocytes, tumor necrosis, sheeting, and poor differentiation (all P<or=0.05). Compared with MSI-L/non-CIMP, MSI-L/CIMP was associated with tumors that had <50% signet ring cell component, marked tumor infiltrating lymphocytes, and poor differentiation (all P<0.05). In conclusion, several pathologic features that have previously been shown to be associated with MSI are also significantly associated with CIMP. Both MSI and CIMP appear to play a role in the pathogenesis of specific morphologic patterns of colorectal carcinoma.

Pseudomyxoma Peritonei of Appendiceal Origin: A Clinicopathologic Analysis of 101 Patients Uniformly Treated at a Single Institution, With Literature Review

Pseudomyxoma peritonei is a clinical term for gelatinous ascites, usually secondary to an appendiceal tumor. The pathologic classification of pseudomyxoma peritonei and its associated appendiceal tumors has been plagued with controversy and confusing terminology. In an effort to clarify this, we reviewed the pathology of 101 patients, all treated at our institution from 1993 to 2005, with pseudomyxoma peritonei of appendiceal origin. All patients were uniformly treated with our standardized protocol. This is the largest pathologic series solely devoted to appendiceal neoplasia with gelatinous ascites. The cases were assigned, according to previously published criteria, to the categories of disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), or PMCA with intermediate (well differentiated) features (PMCA-I), with the exception that any case with a signet-ring cell component was considered as PMCA and not PMCA-I. By histologic category, 58 patients had DPAM, 23 were PMCA, and 20 were PMCA-I.One-year, 3-year, and 5-year survival outcomes were not significantly different between DPAM and PMCA-I. DPAM and PMCA-I also exhibited a roughly equal incidence of parenchymal (beyond the serosa) organ invasion. Survival outcomes were significantly worse for PMCA, compared with PMCA-I and DPAM. After reviewing our data and the literature, mucinous carcinoma peritonei-low grade was applied to the low-grade histology of pseudomyxoma peritonei, including those cases referred to by some as DPAM in the same category as PMCA-I. Cases that are moderately differentiated to poorly differentiated are classified as mucinous carcinoma peritonei-high grade.

Distinct molecular features of colorectal carcinoma with signet ring cell component and colorectal carcinoma with mucinous component

Signet ring cell carcinoma and mucinous carcinoma are distinct subtypes of colorectal adenocarcinoma. The morphologic and molecular spectra of colorectal carcinomas with various signet ring cell components and colorectal carcinomas with various mucinous components, compared to non-mucinous adenocarcinomas, have not been examined. The study groups consisted of 39 carcinomas with various signet ring cell components (‘the signet group'), 167 carcinomas with various mucinous components (‘the mucinous group'), and 457 nonmucinous adenocarcinoma. We visually estimated the amounts of signet ring cell and mucinous components in tumors, and subclassified the signet and mucinous groups according to the amount of each component (≤19, 20–49, and ≥50%). We sequenced BRAF and KRAS, analyzed for microsatellite instability (MSI) and 18q loss of heterozygosity (LOH), and performed immunohistochemistry for TP53, cyclooxygenase-2 (COX2), MLH1, O-6-methylguanine DNA methyltransferase (MGMT), p16 (CDKN2A), and fatty acid synthase (FASN). Signet ring cell carcinoma (≥50% signet ring cell tumors) and ≤49% signet ring cell tumors showed similar molecular features. Except for MSI and MGMT, ≥50% mucinous tumors and ≤49% mucinous tumors also showed similar molecular features. BRAF mutations, MSI, and MLH1 loss were more frequent in both the signet and mucinous groups than nonmucinous carcinoma. More frequent KRAS mutations and less frequent p16 loss and TP53 positivity were observed in the mucinous group than nonmucinous carcinoma. 18q LOH and COX2 overexpression were less common in the signet group than nonmucinous carcinoma. FASN levels were highest in the mucinous group, followed by nonmucinous carcinoma, and lowest in the signet group. In conclusion, a minor (≤49%) signet ring cell or mucinous component in colorectal carcinoma suggests molecular features similar to ≥50% signet ring cell or mucinous carcinoma, respectively. Signet ring cell carcinoma and mucinous carcinoma are related subtypes of colorectal adenocarcinoma, but have molecular features distinct from each other.

Differential Trends in the Intestinal and Diffuse Types of Gastric Carcinoma

To the Editor.—During the last decades a worldwide decline in the incidence of gastric cancer has been observed. Most of this trend can be attributed to the decrease in the intestinal type, whereas the diffuse type has remained relatively constant throughout the years, although with an increase in cases with a signet ring cell component. The recent article by Henson et al 1 provides excellent confirmation of these data in a representative portion of the US population. Among the other features of gastric adenocarcinoma that have shown significant modification during the last 50 years, there is a striking increase in occurrence in the proximal locations (cardia-gastroesophageal junction). 2 In a previous study, 3 conducted in a high-risk area of Italy, that analyzed the clinicopathologic features of gastric carcinomas during a 45-year period, we demonstrated a significant decrease in intestinal type (from 66% to 53%), an increase in diffuse type (from 24% to 43%) together with a decrease in distal locations (from 62% to 50%), and an increase in occurrence in proximal locations (from 13% to 23%). Relating tumor location to histologic types, there was an evident increase in intestinal type in the proximal locations (from 55% to 70%) paralleled by an equivalent decrease in diffuse type (from 44% to 30%), which, instead, increased in the middle and distal locations. These complex ‘‘migrations’’ of sites and types clearly indicate modification in the microenvironment of the stomach due to the changes in dietary habits and carcinogenic factors. Unfortunately, Henson et al 1 were not able to analyze the correlations between tumor location and histologic types due to lack of pertinent information in the files of the Surveillance, Epidemiology, and End Results program. This limitation prevents any etiopathogenetic insight for this important series of gastric carcinomas. Currently available data strongly

Intestinal epithelial lesions associated with signet ring cell carcinoma of the colon and small intestine

The purpose of this study was to investigate the epithelial lesions associated with signet ring cell carcinoma (SRCC) of the colon and small intestine and the possible mechanism of tumour development. Twenty-seven cases of adenocarcinoma with a signet ring cell (SRC) component of the colon and small intestine were divided into three groups depending on the association of the SRCC with: (1) epithelium without definite epithelial dysplasia, (2) adenoma, and (3) common type of adenocarcinoma (CTCA) with SRCC component occupying more than 50%, 30%, or less than 30% of the tumour. Most carcinomas were of T3 or T4 type, using the TNM standard staging system. The SRCC component was histopathologically similar in all groups. In group 1 (four cases, linitis plastica type), the overlying epithelium was normal or showed indefinite epithelial dysplasia and occasionally contained intra-epithelial SRCs. In groups 2 and 3 (two and 21 cases, respectively), seven cases contained multiple foci of intra-epithelial SRCs in areas separated from the invasive carcinoma. Transitional areas between SRCC and adenoma or CTCA were also identified. Immunostaining for p53 showed a varied extent of positive reactivity in 23 SRCC. The degree and the extent of reactivity appeared to increase with the stage of the carcinoma. Most intra-epithelial SRCs were immunoreactive for p53. Linitis plastica SRCC was associated with extensive p53 reactivity of the 'atypical' and the adjacent 'normal' epithelium. SRCC may arise from either CTCA, adenoma, 'atypical' epithelium or a combination of these epithelia. SRCC accounts for the bulk of carcinoma in each of these categories. In linitis plastica SRCC, positive reactivity for p53 is extensive in the adjacent 'normal' colonic epithelium and extends as far as 3cm from the microscopically identified SRCC margin.

Adenocarcinoma of the colon with neuroendocrine features and secretory diarrhea

We report the case of a 63-yr-old man who had severe secretory diarrhea associated with colonic adenocarcinoma, with a prominent signet ring cell component and numerous endocrine cells as demonstrated by positive chromogranin-A staining. Improvement in the secretory diarrhea by the somatostatin analog Sandostatin suggested that the diarrhea was related to a functional neuroendocrine tumor within the colonic tumor, the first case to be reported in the literature.

Primary signet-ring cell carcinoma of the lung: Histochemical and immunohistochemical characterization

To establish criteria for differential diagnosis and to clarify the histogenesis of primary signet-ring cell carcinoma (SRCC) of the lung, five cases were studied by mucin-histochemical and immunohistochemical analyses and compared with SRCC of the gastrointestinal tract and mucus-producing adenocarcinoma of the lung. The proportion of signet-ring cell component varied from 10% to 90% in four cases, and the remaining tumor was a pure SRCC. Mucin-histochemistry showed a close similarity between lung SRCC and goblet cell-type or bronchial gland cell-type adenocarcinoma of the lung. Eighty percent of SRCCs showed positive immunoreactions for lactoferrin, a marker of bronchial gland cell differentiation, the results being consistent with the conclusions in previous studies that lung SRCC is closely related to bronchial gland cell-type adenocarcinoma. The incidence of K- ras mutation detected by the restriction fragment length polymorphism method was relatively high in lung SRCC (three of five) and goblet cell-type adenocarcinoma of the lung (four of four). Mucin-histochemistry indicated that lung SRCC has mucin production similar to that of the colon and colorectal-type SRCCs of the stomach but not to that of gastroduodenal-type SRCC of the stomach. Immunohistochemical staining for MUC-1 and MUC-2 glycoproteins showed a distinct difference; lung SRCC was positive for MUC-1 but negative for MUC-2, whereas colon SRCC and colorectal-type gastric SRCC were negative for MUC-1 but positive for MUC-2. Thus, by a combination of mucin-histochemistry and MUC-1 and MUC-2 immunohistochemistry, primary lung SRCC can be distinguished from metastatic lung SRCC originating in the gastrointestinal tract.

Signet Ring Epithelioid Stromal Tumor of the Small Intestine

Cells having a signet ring appearance can occur in mesenchymal, lymphoid, and other nonepithelial neoplasms. We report the case of an intestinal stromal tumor with smooth muscle differentiation and a prominent signet ring cell component. The presence of signet ring forms of smooth muscle cells in sections of paraffin-embedded tissue often contrasts with a lack of cytoplasmic spaces by electron microscopy, and the ultrastructural finding of signet ring-like areas in the present case can be attributed to the fact that the tissue for electron microscopy was retrieved fromparaffin blocks where this peculiar artifact already existed. Ultrastructural examination of the signet ring-like areas suggests that they originated as retraction spaces which may have resulted from variations in intracellular tension forces related to the distribution of actin filaments.

CA 125 production in desmoplastic small round cell tumor: Report of a case with elevated serum levels and prominent signet ring morphology

Serum assays for CA 125 are often used in the diagnosis and follow-up of patients with gynecologic neoplasms. A case of a 34-year-old woman with desmoplastic small round cell tumor (DSRCT) having an unusual morphology, including the presence of a signet ring cell component, and high serum CA 125 levels that was initially diagnosed as poorly differentiated carcinoma of the ovary is herein reported. Ultrastructurally, the signet ring appearance was shown to be the result of either the presence of intracytoplasmic vacuoles or dilatation of the intercellular space. Immunoperoxidase staining showed strong reactivity for desmin, keratin, vimentin, and CA 125. Immunohistochemical studies were performed on six additional DSRCTs but only two showed focal staining for CA 125. Because the patient's CA 125 serum level decreased after she received chemotherapy and her tumor was removed, and it became elevated again when the disease recurred, it is possible that CA 125 could be used as a marker of persistent and recurrent disease in those uncommon cases of DSRCT in which there are elevated serum levels of this marker at the onset of treatment.

Rare metastases of signet ring cell carcinomas to the scrotum: report of two cases

Metastases of signet ring cell carcinomas to the scrotum are rare. We present 2 patients with this kind of tumor. In 1 patient, the scrotal pathologic examination helped to detect an adenocarcinoma of the appendix with a signet ring cell component, with an extent that had not been apparent clinically. The other patient was seen at an advanced stage of signet ring cell carcinoma of the sigmoid colon following surgical therapy and palliative chemotherapy. The route of metastases seems to be via seeding along the testicular cord and via lymhatic dissemination.