Shellaine R. Frazier

Placement of a covered polyester stent prevents complications from a colorectal anastomotic leak and supports healing: Randomized controlled trial in a large animal model

BACKGROUND Anastomotic leaks after colorectal operation continue to be a significant cause of morbidity. A covered endoluminal stent could seal a leak and eliminate the need for diversion. The aim of this study was to test the efficacy of a temporary covered stent to prevent leak related complications. METHODS Sixteen adult pigs (80-120 lbs) underwent open transection of the rectosigmoid followed by anastomosis with a circular stapler. Eight animals (study group) underwent endoscopic placement of a 21-mm covered polyester stent. Eight control group animals were left without stents. In all animals, a 2-cm leak was created along the anterior portion of the anastomosis. The animals were killed after 2 weeks and evaluated for abdominal infection, fistulae, and adhesions. The anastomosis was excised and the following parameters were assessed by a pathologist blinded to treatment: mucosal interruption (mm), inflammatory response, collagen type I and III, granulation, and fibrosis (grade 0-4). RESULTS Stents were spontaneously expelled between postoperative days 6 and 9. At necropsy, none of the animals in the study group had leak related complications, whereas in the control group, 5 (63%) developed intraabdominal infection (4 abscesses, 1 fistula) at the anastomosis (P = .002). Dense adhesions to the anastomosis were found in 7 (88%) control animals. On histology, anastomotic sites in the study group had significantly less mucosal interruption and granulation. Two pigs in the study group died on postoperative day 7, one due to evisceration and one from bladder necrosis. The mortality result is not different from controls (P = .47), both events seem to be unrelated to stent placement. CONCLUSION Temporary placement of a covered polyester stent across a colorectal anastomosis prevents leak-related complications and supports the healing of anastomotic leaks.

1D5 and 6F11: An immunohistochemical comparison of two monoclonal antibodies for the evaluation of estrogen receptor status in primary breast carcinoma.

The optimal monoclonal antibody to examine steroid hormone receptor status of primary breast carcinoma has yet to be defined. Estrogen receptor status was evaluated in 592 cases using routinely prepared paraffin-embedded tissue samples from primary breast carcinomas with the 1D5 (DAKO, Carpinteria, CA) and 6F11 (Novocastra, Newcastle upon Tyne, England) monoclonal antibodies. The stains were compared, assessing the percentage of positive cells stained and their intensity. They also were examined for nonspecific cytoplasmic staining and fixation artifact. In addition, a cost analysis for their production was performed. Overall, 1D5 and 6F11 showed a 97.5% concordance rate. 6F11 stained a significantly higher percentage of cells (P < .0001), more intensely (P < .0001), with less nonspecific cytoplasmic staining (P < .0001). There was no significant difference in fixation artifact between the 2 clones. The cost of antibody used for preparing a 1D5-stained slide was 86% more than for preparing a 6F11-stained slide (dollars 14.27 vs dollars 7.67).

Elevated Peritoneal Fluid TNF-α Incites Ovarian Early Growth Response Factor 1 Expression and Downstream Protease Mediators: A Correlation With Ovulatory Dysfunction in Endometriosis

Endometriosis-associated infertility manifests itself via multiple, poorly understood mechanisms. Our goal was to characterize signaling pathways, between peritoneal endometriotic lesions and the ovary, leading to failed ovulation. Genome-wide microarray analysis comparing ovarian tissue from an in vivo endometriosis model in the rat (Endo) with controls (Sham) identified 22 differentially expressed genes, including transiently expressed early growth response factor 1 (Egr1). The Egr1 regulates gene requisites for ovulation. The Egr1 promoter is responsive to tumor necrosis factor-alpha (TNF-α) signaling. We hypothesized that altered expression of ovarian EGR1 is induced by elevated peritoneal fluid TNF-α which is upregulated by the presence of peritoneal endometriosis. Endo rats, compared to controls, had more peritoneal fluid TNF-α and quantitative, spatial differences in Egr1 mRNA and EGR1 protein localization in follicular compartments. Interactions between elevated peritoneal fluid TNF-α and overexpression of follicular Egr1/EGR1 expression may affect downstream protease pathways impeding ovulation in endometriosis. Preliminary studies identified similar patterns of EGR1 protein localization in human ovaries from women with endometriosis and compared to those without endometriosis.

Accuracy and Reproducibility of Nuclear/Cytoplasmic Ratio Assessments in Urinary Cytology Specimens.

Evaluation of the nuclear to cytoplasmic ratio is commonly used for assessment of the presence of malignancy and for grading and typing of malignant neoplasms. Despite its widespread usage, little information exists regarding the accuracy and reproducibility of non‐automated assessment.

Characterization of spontaneous mammary gland carcinomas in female baboons

Spontaneous mammary gland carcinomas occurred in five baboons during a 13‐year period at Southwest Foundation for Biomedical Research. The affected baboons ranged in age from 21 to 33 years. Menopause in the baboon occurs at approximately 26 years of age. All five animals had typical invasive ductal carcinoma. Morphologically, the tumors were characterized by neoplastic cells arranged from pseudopapillary and cribiform to more poorly differentiated solid cellular growth patterns. Additional features included lack of tubule formation (4/5), marked nuclear pleomorphism (5/5), a high mitotic rate (4/5) and tumor necrosis (4/5). Applying a grading system used for breast cancer in women, four tumors were graded as poorly differentiated carcinomas and one was graded as moderately differentiated. Co‐existant ductal carcinoma in situ (DCIS) was observed in three of the mammary tumors. Metastases to the regional lymph nodes were confirmed in two animals, both with histological evidence of lymphovascular invasion in the primary tumor. Distant metastases were observed in only one animal. Immunohistochemical staining for human therapeutic markers revealed 2/5 tumors strongly positive for estrogen receptor, 1/5 strongly positive for progesterone receptor and 4/4 negative for HER2 expression. Although the incidence appears to be low, these five cases of mammary carcinoma in female baboons suggest that when present baboon mammary carcinoma is usually of ductal origin and behaves similar to a human breast carcinoma.

Interobserver reproducibility for HER2/neu immunohistochemistry: A comparison of reproducibility for the HercepTest™ and the 4B5 antibody clone

BACKGROUND IHC results for HER2/neu vary with replicate testing using the same antibody clone and when alternate clones are utilized. A number of factors appear to be responsible for this variability, including fixation times, equipment utilized and training and experience of staff. A number of studies have documented interobserver variability for a single antibody clone but few have evaluated reproducibility between antibody clones and which clones demonstrate the highest degree of interobserver reproducibility. DESIGN We studied a series of 93 cases stained by both the HercepTest™ and the 4B5 clone for interobserver reproducibility. Formalin-fixed, paraffin-embedded sections were stained by the immunohistochemical technique using the manufactures directions for both the HercepTest™ and the 4B5 clone. FISH testing was performed on formalin-fixed paraffin embedded sections according to the PathVysion HER-2 DNA probe kit instructions. RESULTS Absolute agreement rate for Hercep was 85%. Absolute agreement for 4B5 was 69%. This difference was statistically significant (p<0.0001). The chance-corrected agreement (weighted kappa) for the HercepTest™ was 79% and 71% for 4B5 (p<0.0001). Absolute agreement between antibody clones was 58% with the chance corrected agreement being 51%. Absolute agreement of 4B5 with FISH was significantly greater than that of the HercepTest™ (54% vs 35%). CONCLUSION Agreement between evaluators was greater with the HercepTest. However, agreement with FISH results was superior for the 4B5 clone. Interobserver agreement was less than the 95% agreement threshold recommended by the ASCO/CAP guidelines for development of a new testing method for HER2 evaluation.

Combined small-cell lung carcinoma: An institutional experience.

The purpose of this study is to determine prognostic factors and survival in patients who present with combined small‐cell lung cancer (SCLC).

Histomorphologic Features of Biopsy Sites Following Excisional and Core Needle Biopsies of the Breast

Mammographic studies have documented a number of architectural changes occurring around breast biopsy sites. These changes are well described in the radiological literature, but similar studies do not appear to be present in the pathology literature. We reviewed 100 consecutive mastectomy specimens from women who had undergone prior core needle or excisional biopsies. Multiple sections of the needle tract or excisional biopsy site were reviewed and morphologic findings reported. Hemorrhage, fat necrosis, granulation tissue, necrosis of fibrous tissue, and epithelium along with fibrosis and foreign body type giant cells were common features. Less frequent were areas of synovial metaplasia, atypical spindle cells, atypical duct‐like structures, single atypical cells, squamous metaplasia, proliferations of abnormal blood vessels, and hemosiderin deposition. The misinterpretation of atypical spindle cells, single atypical cells, atypical duct‐like structures and squamous metaplasia could result in the false‐positive diagnosis of residual malignancy. Careful attention to the reactive nature of these changes aids in their distinction from carcinoma.

Impact of Consensus Conference Review on Diagnostic Disagreements in the Evaluation of Cervical Biopsy Specimens

Objectives To determine the impact of consensus conferences on the frequency of discrepant cases in a surgical pathology practice. Methods The percentage of discrepancies in cases reviewed at a weekly consensus conference was calculated for the first and last months of a 13-month period. Both interrater agreement and agreement with the consensus diagnoses were assessed. A total of 309 diagnoses were performed for the first month and 518 for the last month. Both absolute and chance-corrected agreement were calculated for each period. Results Absolute agreement rate increased from 91.2% in the first month to 98.2% in the final month. Chance-corrected agreement increased from 0.80 in the first month to 0.97 in the final month. Conclusions The consensus conference technique appears to be a useful method to reduce intradepartmental diagnostic discrepancies. Both absolute and chance-corrected agreement are improved by using consensus conferences.

Quality assurance of anatomic pathology diagnoses: Comparison of alternate approaches

OBJECTIVES Traditionally, a 10% review has been the basis for quality assurance programs in anatomic pathology. The effectiveness of such reviews has been questioned and alternative methodologies suggested. The study investigates the error detection rates for four quality assurance protocols. METHODS The detection rate for diagnostic errors in surgical pathology was calculated over a one year period using four different review procedures comprising: random 10% review, correlation of internal and external diagnoses following solicited external expert opinion, correlation of internal diagnoses with outside diagnoses in cases sent for review at a second institution treating the patient along with a focused review of dermatopathology cases over a 3 month period. Error rate was expressed as percentage of reviewed cases where the initial diagnosis differed from the review diagnosis. Error rates detected by each method were compared among the methods RESULTS: The 10% random review detected seventeen errors in 2147 cases (0.8%). Solicited case consultations requested by clinicians or internal pathologists detected five diagnostic errors in seventy cases (7.1%). Unsolicited reviews by outside institutions in the course of patient care detected three diagnostic errors in 190 cases (1.6%). Review of the dermatopathology material disclosed 5 diagnostic errors in 59 cases (8.5%). CONCLUSIONS Focused reviews initiated by diagnostic concerns of a clinician or pathologist, unsolicited reviews because of treatment at another institution and sub-specialty based reviews appear to be more effective in detecting diagnostic errors than the 10% random review. Quality assurance programs should include focused reviews in addition to 10% random review to maximize error detection.