Recent studies have shown that immunohistochemical evaluation of MYC protein expression in diffuse large B-cell lymphoma is a useful prognostic tool with high concordance rate among pathologists. Concordance in these studies was assessed among few pathologists from one institution by scoring tissue microarrays. In daily practice, MYC evaluation is performed on entire tumor sections by a diverse group of pathologists. In our study, nine hematopathologists from two institutions scored whole-tissue sections of two sets of cases. The training set included 13 cases of diffuse large B-cell lymphoma and 4 cases of Burkitt lymphoma. The validation set included 18 cases of diffuse large B-cell lymphoma and 1 case of Burkitt lymphoma. MYC positivity was defined as Z40% of tumor cells demonstrating nuclear staining similar to prior studies. The mean score for each case was used to determine MYC status with discrepant cases defined as having any score causing a different MYC status designation. Discrepant cases from the training set were characterized by staining heterogeneity, extensive necrosis or crush artifact and had mean scores within 15 percentage points of 40%. Cases from the validation set that demonstrated any of these features were scored twice on two different days. Overall concordance was moderate (Kappa score: 0.68, P-valueo0.001) with no significant change between the two sets (Kappa scores: 0.69 vs 0.67). Thirty-nine percent of cases were discrepant. The findings indicate that a significant number of diffuse large B-cell lymphomas are inherently difficult to score due to staining heterogeneity. The effect of heterogeneity can be under-represented when concordance is measured among few pathologists scoring tissue microarrays. Careful scoring strategy in our study failed to improve concordance. In the absence of specific instructions on how to deal with heterogeneity, caution is advised when evaluating MYC expression in diffuse large B-cell lymphoma.

In complex BM cases, the presence of ≥30% CD34+ MKs constitutes a potentially useful diagnostic tool with which to distinguish non-acute myeloid neoplasms and MBA from non-MBA reactive conditions, for minimal additional cost.

The management of laboratory testing continues to be an ongoing challenge. We describe the design of a laboratory utilization and management program for the cost-effective, clinically relevant use of microbiological "send-out" tests, implemented in close collaboration with the Division of Infectious Diseases (ID) at an urban, medium-sized academic hospital. The structure of this program defines the clinical pathology (CP) house staff member as the gatekeeper for approval of send-out microbiological tests. Orders are received by "client services" staff members who have been instructed to divert send-out test requests to the CP house staff. Medical records are reviewed, and requests are approved or held, pending interaction with clinical house staff. The interaction may be a phone call or require direct contact and discussion. The interaction with clinical house staff is facilitated when ID has been consulted in the care of a patient. Pending patient test requests are discussed at interdisciplinary microbiology rounds, which are conducted 3 times a week in the microbiology laboratory. At these rounds, ID and CP house staff and the attending microbiologist discuss ongoing patient care and present laboratory testing requests. We retrospectively analyzed send-out test requisitions to evaluate the impact of this interdisciplinary program. A total of 403 requisitions were screened by CP house staff: 71.2% (287) were approved, and 28.6% (116) where canceled. Canceled tests were further delineated into 2 categories that best described why the test was canceled, including preanalytic problems (60%) and no clinical indication for the test (40%). In our experience, when ID was present at microbiology rounds, it was significantly easier to facilitate which send-out tests were needed or relevant to patient care. Our goal through this interdisciplinary approach is to further the cost-effective, clinically relevant use of laboratory testing, thereby allowing us to serve as a resource to hospital house staff and laboratory management teams. Category:Medical Microbiology