Robert V. Rouse

Prevalence of Nonpolypoid (Flat and Depressed) Colorectal Neoplasms in Asymptomatic and Symptomatic Adults

CONTEXT Colorectal cancer is the second leading cause of cancer death in the United States. Prevention has focused on the detection and removal of polypoid neoplasms. Data are limited on the significance of nonpolypoid colorectal neoplasms (NP-CRNs). OBJECTIVES To determine the prevalence of NP-CRNs in a veterans hospital population and to characterize their association with colorectal cancer. DESIGN, SETTING, AND PATIENTS Cross-sectional study at a veterans hospital in California with 1819 patients undergoing elective colonoscopy from July 2003 to June 2004. MAIN OUTCOME MEASURES Endoscopic appearance, location, size, histology, and depth of invasion of neoplasms. RESULTS The overall prevalence of NP-CRNs was 9.35% (95% confidence interval [95% CI], 8.05%-10.78%; n = 170). The prevalence of NP-CRNs in the subpopulations for screening, surveillance, and symptoms was 5.84% (95% CI, 4.13%-8.00%; n = 36), 15.44% (95% CI, 12.76%-18.44%; n = 101), and 6.01% (95% CI, 4.17%-8.34%; n = 33), respectively. The overall prevalence of NP-CRNs with in situ or submucosal invasive carcinoma was 0.82% (95% CI, 0.46%-1.36%; n = 15); in the screening population, the prevalence was 0.32% (95% CI, 0.04%-1.17%; n = 2). Overall, NP-CRNs were more likely to contain carcinoma (odds ratio, 9.78; 95% CI, 3.93-24.4) than polypoid lesions, irrespective of the size. The positive size-adjusted association of NP-CRNs with in situ or submucosal invasive carcinoma was also observed in subpopulations for screening (odds ratio, 2.01; 95% CI, 0.27-15.3) and surveillance (odds ratio, 63.7; 95% CI, 9.41-431). The depressed type had the highest risk (33%). Nonpolypoid colorectal neoplasms containing carcinoma were smaller in diameter as compared with the polypoid ones (mean [SD] diameter, 15.9 [10.2] mm vs 19.2 [9.6] mm, respectively). The procedure times did not change appreciably as compared with historical controls. CONCLUSION In this group of veteran patients, NP-CRNs were relatively common lesions diagnosed during routine colonoscopy and had a greater association with carcinoma compared with polypoid neoplasms, irrespective of size.

Expression of CD34 by solitary fibrous tumors of the pleura, mediastinum, and lung.

Solitary fibrous tumors are rare neoplasms that most commonly involve the pleura, mediastinum, and lung. Because they lack distinctive histologic features, immunologic staining has frequently been employed to exclude other neoplasms in the differential diagnosis. Their reported phenotype to date is generally negative, notably for muscle-type actins, desmin, keratin, and S-100 protein. Although this testing is of some help, it does not serve to distinguish all processes in the differential diagnosis, and when it does, it places too great an emphasis on a negative finding to make a diagnosis. We report here that CD34 monoclonal antibodies reacted with 11 of 14 solitary fibrous tumors in paraffin sections. Thus, they provide a positive marker that distinguishes the solitary fibrous tumor from most elements in the differential diagnosis.

New models and online calculator for predicting non-sentinel lymph node status in sentinel lymph node positive breast cancer patients

BackgroundCurrent practice is to perform a completion axillary lymph node dissection (ALND) for breast cancer patients with tumor-involved sentinel lymph nodes (SLNs), although fewer than half will have non-sentinel node (NSLN) metastasis. Our goal was to develop new models to quantify the risk of NSLN metastasis in SLN-positive patients and to compare predictive capabilities to another widely used model.MethodsWe constructed three models to predict NSLN status: recursive partitioning with receiver operating characteristic curves (RP-ROC), boosted Classification and Regression Trees (CART), and multivariate logistic regression (MLR) informed by CART. Data were compiled from a multicenter Northern California and Oregon database of 784 patients who prospectively underwent SLN biopsy and completion ALND. We compared the predictive abilities of our best model and the Memorial Sloan-Kettering Breast Cancer Nomogram (Nomogram) in our dataset and an independent dataset from Northwestern University.Results285 patients had positive SLNs, of which 213 had known angiolymphatic invasion status and 171 had complete pathologic data including hormone receptor status. 264 (93%) patients had limited SLN disease (micrometastasis, 70%, or isolated tumor cells, 23%). 101 (35%) of all SLN-positive patients had tumor-involved NSLNs. Three variables (tumor size, angiolymphatic invasion, and SLN metastasis size) predicted risk in all our models. RP-ROC and boosted CART stratified patients into four risk levels. MLR informed by CART was most accurate. Using two composite predictors calculated from three variables, MLR informed by CART was more accurate than the Nomogram computed using eight predictors. In our dataset, area under ROC curve (AUC) was 0.83/0.85 for MLR (n = 213/n = 171) and 0.77 for Nomogram (n = 171). When applied to an independent dataset (n = 77), AUC was 0.74 for our model and 0.62 for Nomogram. The composite predictors in our model were the product of angiolymphatic invasion and size of SLN metastasis, and the product of tumor size and square of SLN metastasis size.ConclusionWe present a new model developed from a community-based SLN database that uses only three rather than eight variables to achieve higher accuracy than the Nomogram for predicting NSLN status in two different datasets.

Hep Par 1 antibody stain for the differential diagnosis of hepatocellular carcinoma: 676 tumors tested using tissue microarráys and conventional tissue sections

A well-characterized positive marker for hepatocellular differentiation would be a useful tool for the diagnosis of hepatocellular carcinoma (HCC). The recently commercially available Hep Par 1 antibody (clone OCH1E5.2.10) has been reported to be a sensitive marker for HCC in paraffin embedded sections. Of non-hepatocellular tumors, occasional carcinomas have been reported to stain, most frequently gastric adenocarcinomas. This study further evaluated the staining of this antibody on a large number of neoplasms using tissue microarray technology as well as conventional tissue sections. Six hundred seventy-six tumors, including 19 cases of HCC, were tested. Eighteen of 19 cases of HCC were positive, 3 showing <5% staining. Two cases negative on the array showed focal staining when whole tissue sections from the same tumors were used. 16 of 34 cases of gastric carcinomas gave positive reactions, 4 of these showed less than 5% staining. Staining of gastric carcinomas was not limited to signet ring-type carcinomas or to areas of hepatoid differentiation. Only 1 of 11 cases of cholangiocarcinoma showed focal staining. We also noted several other tumors to stain occasionally, including adrenal cortical carcinoma (3/13), yolk sac tumor (2/9), colonic adenocarcinoma (8/106), lung carcinoma (3/52), ovarian carcinoma (5/48), and endocervical adenocarcinoma (1/5). We did not observe staining in pancreatic carcinoma (11), renal cell carcinoma (36), breast carcinoma (85), melanoma (25), or mesothelioma (5). This study supports Hep Par 1 as a useful marker in the differential diagnosis of HCC, but with significant limitations. Cautious use of this antibody in a panel with other positive (alpha fetoprotein, CD10, polyclonal carcinoembryonic antigen) and negative (epithelial membrane antigen, monoclonal carcinoembryonic antigen, CD15) markers of hepatocellular differentiation may aid in the accurate diagnosis of HCC.

Prostatic adenocarcinoma with endometrioid features: clinical, pathologic, and ultrastructural findings

Thirteen cases of prostatic adenocarcinoma with endometrioid features were reviewed. The patients were older men (49-81 years) presenting with symptoms of hematuria and urinary obstruction. Each of the tumors displayed exophytic growth into the prostatic urethra, with involvement of the verumontanum. The urethral orifices of the large (primary) prostatic ducts were uniformly involved, and coexistent invasive (acinar) adenocarcinoma was identified in 10 cases (77%). The tumors exhibited a complex glandular pattern strikingly similar to uterine endometrial carcinoma, with prominent papillary formation in six cases. All cases demonstrated intense cytoplasmic immunoreactivity for prostatic acid phosphatase and prostate- specific antigen in at least part of the tumor. Focal staining for carcinoembryonic antigen was seen in three cases. Five tumors examined ultrastructurally demonstrated typical features of prostatic adenocarcinoma. Follow-up information was available on all 13 patients (6-83 months). Seven patients died of metastatic tumor (9-70 months after diagnosis), and the other six patients exhibited recurrent local or metastatic tumor. The sites of metastases were identical to those seen with invasive “acinar” prostatic adenocarcinoma, including pelvic lymph nodes, bones, and lungs. Crude 5-year survival was 15%, with a mean survival of 37 months. Adjuvant therapy provided palliative relief for many patients, but did not appear to influence survival. These findings indicate that endometrioid carcinoma is a histologically distinct variant of prostatic adenocarcinoma, with a more aggressive clinical behavior than previously thought.

Intraepidermal cytokeratin 7 expression is not restricted to Paget cells but is also seen in Toker cells and Merkel cells.

Histologically, extramammary Pagets disease and mammary Pagets disease (MPD) are characterized by large atypical cells distributed throughout the epidermis. Although classic examples of these disorders are easily diagnosed on morphologic grounds, some cases may cause differential diagnostic problems. Immunohistology with a wide variety of antibodies has been used as an aid for the identification of Paget cells, for their distinction from other entities, and for investigation of the origin or nature of the disorder. Recently, cytokeratin 7 has been proposed as a specific and 100% sensitive marker for Pagets disease. We studied 22 cases of mammary Pagets disease and 22 cases of extramammary Pagets disease with and without an underlying malignancy for their reactivity with monoclonal antibodies to cytokeratin 7 (CK7) and cytokeratin 20 (CK20). Our studies show that anti-CK7 is an effective but not 100% sensitive marker for Paget cells, staining 21 of 22 cases of mammary Pagets disease and 19 of 22 cases of extramammary Pagets disease, whereas CK20 stained 0 of 17 cases of mammary Pagets disease and 6 of 19 cases of extramammary Pagets disease. We also demonstrate that CK7, but not CK20, highlights intraepidermal clear cells with bland nuclear features (Toker cells) that have been reported in 11% of normal nipples. By using CK7 as a marker, however, we were able to identify Toker cells in most of the nipples we studied: 8 of 15 nipples from mastectomy patients without Pagets disease, and 15 of 18 autopsy cases (both male and female) with normal breasts and nipples. It also permitted us to perform more extensive phenotyping on them, showing that Toker cells share similar antigens with Paget cells and with cells lining the underlying normal lactiferous ducts. In 7 of 15 cases containing CK20-positive Merkel cells, CK7 was also seen to stain Merkel cells. In infrequent cases, Toker cells or Merkel cells may be so numerous focally that a CK7 stain may raise the possibility of involvement of the nipple by Pagets disease. An awareness of the CK7 reactivity of Toker cells and Merkel cells as well as attention to the cytologic features of the case should avoid this problem.

Desmoplastic and spindle-cell malignant melanoma. An immunohistochemical study.

The clinical, histologic, and immunohistologic features of 22 desmoplastic melanomas (DMM), 10 mixed desmoplastic and spindle-cell melanomas (DMM/SMM), and two cellular spindle-cell melanomas (SMM) were studied. Patients ranged in age from 35 to 91 years (mean, 67) and included 23 men and 11 women. Seventeen cases occurred in sun-damaged skin of the head and neck. 11 were on the extremities, and six on the trunk. Except for two cases, all were Clarks level IV or V. Twenty-two (65%) cases were associated with a recognizable overlying pigmented lesion. Thirty of 32 (94%) DMM and DMM/SMM were clearly positive for S100. S100 staining was limited to < 5% of the spindle cells in two DMM/SMM. All DMM were negative when stained with HMB45. Three DMM/ SMM were immunoreactive with HMB45, as were both SMM. CD68 staining was limited to < 5% of the spindle cells in two of 32 DMM and DMM/SMM and 20% of the cells in one of two SMM. Nine (32%) DMM and DMM/SMM contained significant numbers of spindle cells immunoreactive for SMA but not desmin. In five cases, the number of actin-positive spindle cells. Two color stains for SMA and S100 demonstrated that these smooth-muscle actin positive cells constituted a separate spindle-cell population, consistent with reactive myofibroblasts. This study indicates that the immunohistologic features of desmoplastic melanoma differ from those of conventional melanoma. If a problematic spindle-cell skin lesion is a suspected melanocytic process, HMB45 is unlikely to provide confirmatory (or exclusionary) evidence for the diagnosis of DMM. Similarly, because of the variability in S100 expression in this neoplasm, the absence of S100 staining should not be relied on too heavily to exclude DMM if the clinical and histologic features favor that diagnosis. Caution should be exercised in the interpretation of numerous actin-positive spindle cells in isolation of additional confirmatory or exclusionary data as desmoplastic melanomas may contain significant numbers of these cells.

CD34 expression by gastrointestinal tract stromal tumors

Gastrointestinal stromal tumors (GISTs) are neoplasms arising in the wall of the gastrointestinal tract that frequently show evidence of smooth muscle differentiation, either by their appearance alone or by immunohistology. A significant number of these neoplasms fail to react with any markers of muscle differentiation, however. A subset of these neoplasms have epithelioid features, and the presence of these features can give rise to confusion with other neoplasms, such as carcinomas and melanomas. Here we show that the CD34 monoclonal antibody My10 reacts with 19 of 23 (83%) of these lesions, including both those with and without epithelioid features. Five of 10 epithelioid and one of 13 spindled neoplasms lacked detectable muscle-specific actin (MSA), smooth muscle actin (SMA), and desmin; all six were CD34 reactive. Immunoblotting experiments show that the antigen on these stromal neoplasms has a molecular weight identical to that found on hematopoietic cells. The frequency and intensity of the reactivity of GISTs with anti-CD34 antibodies are distinctly higher than those reported for smooth muscle neoplasms of soft tissue and myometrium. This reactivity can be a useful adjunct in the diagnosis of difficult cases, especially in those exhibiting epithelioid morphology.

Atypical fibroxanthoma: multiple immunohistologic profiles

The clinical, histologic, and immunohistochemical features of 37 cases of atypical fibroxanthoma (AFX) are presented. Patients ranged in age from 13 to 95 years (mean, 69). Thirty AFXs occurred on the head and neck, and seven lesions developed on the trunk or extremities. The morphologic spectrum varied from a predominant spindle cell pattern with focal cellular pleomorphism to numerous bizarre epithelioid cells with multinucleated giant cells. The spindle cell component in these lesions ranged from 10 to 90% of the constituent cells. Most (31 of 37) AFXs also contained pleomorphic giant cells. Small numbers of S-100-positive dendritic cells were present in 11 cases. Five cases showed variable reactivity with antifactor- XIIIa. Fifteen (41%) of the AFXs stained for muscle- specific actin or smooth muscle actin and 21 (57%) expressed CD68 (detected with monoclonal KP1), a monocyte-macrophage marker. Reactivity for these antigens was seen in all lesional cell types (spindled, epithelioid, and bizarre). Four immunologic profiles were observed: CD68 only (13 cases), actin only (7 cases), double positives (8 cases), and double negatives (9 cases). No significant differences in staining characteristics were observed in the head and neck versus the trunk and extremity lesions. These results expand the immunohistochemical spectrum of AFX, suggest the concept of heterogenous bimodal “fibrohistiocytic” and “myofibroblastic” phenotypes, and provide further evidence that an integrative, nonalgorithmic approach is necessary in the analysis of these and other spindle cell cutaneous lesions.

Extragonadal germ cell tumors: a review with emphasis on pathologic features, clinical prognostic variables, and differential diagnostic considerations.

Extragonadal germ cell tumors (GCTs) are relatively uncommon, but represent 1% to 5% of all GCTs. Their morphology varies widely and includes mature teratoma, immature teratoma, seminoma, yolk sac tumor, embryonal carcinoma, choriocarcinoma, and mixed GCTs. Noncentral nervous system extragonadal GCTs are found in a variety of anatomic locations, but most commonly affect the mediastinum and sacrococcygeal region. Predicting behavior in these tumors can be confusing because it is based on a combination of varying factors including patient age, histologic subtype, anatomic site, and clinical stage. This review attempts to dissect these issues by separating the discussion into 3 age groups: neonatal (congenital), children (prepubertal), and adult (postpubertal). Within each individual age group, we cover the significance of anatomic site, morphology, and staging parameters. In addition, we discuss the spectrum of associated secondary malignancies and their impact on patient outcome. Finally, we provide a detailed survey of differential diagnostic considerations grouped by anatomic site.