Incorporation of Digital Gene Expression Profiling for Cell-of-Origin Determination (Lymph2Cx Testing) into the Routine Work-Up of Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphomas (DLBCL) represent a clinically heterogeneous group of lymphomas that are classified together based on similarities in morphology and immunophenotype. Gene expression profiling further classifies DLBCL into distinct molecular subgroups based on cell-of-origin (COO), including Germinal Center B-cell type, Activated B-cell type, and Unclassified type. COO assignment of DLBCL has important biological and prognostic significance, as well as emerging therapeutic implications. Herein, we describe the first clinical validation of a digital gene expression profiling assay (Lymph2Cx) to perform COO assignment in the routine work-up of DLBCL using formalin-fixed paraffin-embedded (FFPE) tissue sections and describe the results of 90 consecutive DLBCL cases analyzed prospectively by a College of American Pathologists/Clinical Laboratory Improvement Amendments (CAP/CLIA)-certified clinical molecular diagnostics laboratory.

Is Routine Pathologic Evaluation of Sebaceous Cysts Necessary?: A 15-Year Retrospective Review of a Single Institution.

A question arose in our practice of whether all cysts considered sebaceous should be sent for pathologic evaluation. To address this controversial topic, we performed a retrospective study of our single institution's histopathology database. A natural language search of the CoPath database across the institution was undertaken using the diagnosis of sebaceous cyst, epidermal cyst, epidermoid cyst, epithelial cyst, infundibular cyst, pilar cyst, trichilemmal cyst, and steatocystoma. A surgical pathologic review of all specimens with one of these preexcision diagnoses was included in the 15-year retrospective study of 1998 to 2013. All slides were confirmed to have undergone histopathologic review, and the preexcision diagnoses were compared with the postexcision diagnoses. Chart review was undertaken in instances of a diagnosis of malignancy. A total of 13,746 samples were identified. Forty-eight specimens had histopathologic diagnosis of malignancy, for an incidence of 0.3% and with the most common malignancy being squamous cell carcinoma. Chart review showed that for all cases, the surgeons reported uncertainty with regard to the diagnosis because of history or physical characteristics, or both. In addition, a comprehensive literature review showed results consistent with our data and illustrated 19 cases during the past 10 years in which most of the findings were squamous cell carcinoma. We propose the recommendation that routine pathologic evaluation of sebaceous cysts is necessary only when clinical suspicion exists.

Decreased faux addenda following standardisation of pathologist practice.

AIMS: We wanted to improve the quality of histopathology addenda and amendments by introducing standardised nomenclature and procedures. METHODS: We standardised amendment and addenda definitions, implemented a pathologist visual work tool, and evaluated and quantitated all amendments and addenda for 3 months prior to implementation and 17 months after. RESULTS: In the 3-month pre-intervention period, 32 of 979 addenda (3.3%) were misused and 18 of 98 amendments (18.4%) were incorrectly classified. In the 17-month post-intervention period, 57 of 5906 addenda (1.0%) were misused and 54 of 752 amendments (7.2%) were incorrectly classified. These differences were statistically significant (p<0.0001). CONCLUSIONS: The introduction of standardised nomenclature and a visual work tool significantly improved the quality of histopathology addenda and amendments.