Uniform Labeling of Blocks and Slides in Surgical Pathology: Guideline From the College of American Pathologists Pathology and Laboratory Quality Center and the National Society for Histotechnology.

CONTEXT: The labeling of paraffin blocks and microscopic glass slides in the practice of surgical pathology varies from institution to institution and introduces potential risk of preanalytic error. Currently there are no evidence-based guidelines regarding the uniform labeling of these materials. OBJECTIVE: To develop recommendations that will address the need for adequate patient identification and provide a consistent method of identifying slides originating from a particular block. DESIGN: - The College of American Pathologists Pathology and Laboratory Quality Center and the National Society for Histotechnology convened a panel of pathologists and histotechnologists with expertise in histology laboratory quality practices to develop labeling recommendations. A systematic evidence review was conducted to address 6 main key questions. Recommendations were derived from strength of evidence, open comment feedback, and expert panel consensus. RESULTS: Twelve guideline statements were established to assist pathology laboratories in developing standardized block and slide labeling practices. These guidelines call for the use of 2 patient identifiers, 1 of which includes the accession number and case type, on all paraffin blocks and slides. Recommendations were also developed to address the order and format in which identifying elements should appear. CONCLUSIONS: Uniform labeling of paraffin blocks and slides derived from patient specimens will provide an important enhancement to patient safety by assuring that all preparations derived from a patient's tissue can be uniquely and unambiguously linked to that patient. Adoption of standardized practices additionally will improve patient care by facilitating interpretation of histologic sections when they are referred in consultation to a second institution.

Immunohistochemistry validation procedures and practices: a College of American Pathologists survey of 727 laboratories.

CONTEXT: The immunohistochemistry (IHC) laboratory represents a dynamic area of surgical pathology with limited practice guidelines. Studies have shown significant interlaboratory variability in results. OBJECTIVE: To establish baseline parameters for IHC validation procedures and practice, and to assess their feasibility of implementation. DESIGN: In September 2010, a questionnaire was distributed by the College of American Pathologists. It was composed of 32 questions relating to nonpredictive assays as well as non-US Food and Drug Administration (non-FDA)-approved, predictive IHC assays other than human epidermal growth factor 2 (HER2/neu). RESULTS: For non-FDA approved, nonpredictive IHC assays, 68% of laboratories had a written validation procedure. Eighty-six percent of laboratories validated the most recently introduced nonpredictive antibody. Seventy-five percent used 21 or fewer total cases for the validation and 40% used weakly or focally positive cases. Forty-six percent of respondents had a written procedure for validation procedures for non-FDA approved, predictive marker IHC assays other than HER2/neu. Seventy-five percent of laboratories validated the most recently introduced predictive antibody other than HER2/neu. Fewer than half used 25 or more cases for the validation, and 47% used weakly or focally positive cases. CONCLUSION: Some laboratories have written validation procedures that appear to build upon HER2/neu testing guidelines. Some laboratories also manage to validate new antibodies according to those standards; however, many do not. There appears to be a need for further validation guideline development for nonpredictive and non-FDA approved predictive antibody IHC assays.

Course introduction and selection of immunohistochemical staining panels: principles and importance of incorporating clinical information. The 5th annual retreat for applied immunohistochemistry and molecular pathology january 30th-february 2, 2011, coral gables, Florida.

Among the core principles in the practice of immunohistochemistry is the use of carefully chosen marker panels. Choosing an appropriate panel of antibodies is predicated on a sound differential diagnosis that is based on detailed examination of hematoxylin and eosin-stained slides. The panel should contain antibodies designed to be immunoreactive in the most likely disease(s) in the differential as well as selected negative markers. In addition, the importance of detailed historical and clinical information in constructing the differential diagnosis and panel selection cannot be understated. Two cases from the Case Presentation sessions of the 5th Annual Retreat for Applied Immunohistochemistry and Molecular Pathology are summarized to illustrate these points. The first case is that of metastatic well-differentiated neuroendocrine tumor (carcinoid) tumor presenting as a breast mass. The second is that of a squamous cell carcinoma of the lung mimicking a tumor with admixed glandular differentiation by entrapment and disruption of bronchial glands. Application of a select immunohistochemistry panel in light of the differential diagnosis and importance of making a specific diagnosis are discussed.

Consensus recommendations on estrogen receptor testing in breast cancer by immunohistochemistry.

Estrogen receptor (ER) status in breast cancer is currently the most important predictive biomarker that determines breast cancer prognosis after treatment with endocrine therapy. Although immunohistochemistry has been widely viewed as the gold standard methodology for ER testing in breast cancer, lack of standardized procedures, and lack of regulatory adherence to testing guidelines has resulted in high rates of "false-negative" results worldwide. Standardized testing is only possible after all aspects of ER testing--preanalytical, analytical, and postanalytical, have been closely controlled. A meeting of the "ad-hoc committee" of expert pathologists, technologists, and scientists, representing academic centers, reference laboratories, and various agencies, issued standardization testing recommendations, aimed at optimization of clinical ER testing environment, as a step toward improved standardized testing.

Bile-induced laryngitis: is there a basis in evidence?

Most agree that bile reflux occurs with regularity in an otherwise healthy population and that biliary and acid reflux may play a synergistic role in damaging esophageal mucosa. But to what extent is laryngeal mucosa at risk? We constructed a saline-controlled rat model (n = 40) in which active component solutions of bile--taurocholic acid and chenodeoxycholic acid--were applied to intact laryngeal mucosa at various pH levels. Histologic sampling of the laryngeal mucosa allowed inflammation scores to be generated by a pathologist blinded to the solutions used. Both taurocholic acid at acid pH and chenodeoxycholic acid at basic pH preferentially induced statistically greater inflammation scores than did the saline control, approaching or exceeding inflammation scores attributed to hydrochloric acid at pH 1.2. These observations may clarify reasons for failure to uniformly control laryngeal injury by adequate suppression of gastric acid alone and may further justify alternative methods of laryngeal protection in patients refractory to adequate acid control.

Thyroid transcription factor-1: a review.

Thyroid transcription factor-1 (TTF-1) is a 38-kd homeodomain containing DNA-binding protein originally identified in follicular cells of the thyroid and subsequently in pneumocytes. This review focuses on the utility of antisera in TTF-1 immunohistochemical staining in the diagnosis of neoplastic conditions. Based on published studies to date, anti-TTF-1 is a very useful reagent in distinguishing pulmonary adenocarcinoma from other primary carcinomas, identifying differentiated thyroid neoplasms, distinguishing mesothelioma from pulmonary adenocarcinoma, and distinguishing small cell carcinoma of the lung from Merkel cell carcinoma. It may also be useful in distinguishing neuroendocrine (NE) tumors of the lung from well-differentiated NE tumors from other sites, such as the intestine.