Automated pattern-guided principal component analysis vs expert-based immunophenotypic classification of B-cell chronic lymphoproliferative disorders: a step forward in the standardization of clinical immunophenotyping

Immunophenotypic characterization of B-cell chronic lymphoproliferative disorders (B-CLPD) is becoming increasingly complex due to usage of progressively larger panels of reagents and a high number of World Health Organization (WHO) entities. Typically, data analysis is performed separately for each stained aliquot of a sample; subsequently, an expert interprets the overall immunophenotypic profile (IP) of neoplastic B-cells and assigns it to specific diagnostic categories. We constructed a principal component analysis (PCA)-based tool to guide immunophenotypic classification of B-CLPD. Three reference groups of immunophenotypic data files—B-cell chronic lymphocytic leukemias (B-CLL; n=10), mantle cell (MCL; n=10) and follicular lymphomas (FL; n=10)—were built. Subsequently, each of the 175 cases studied was evaluated and assigned to either one of the three reference groups or to none of them (other B-CLPD). Most cases (89%) were correctly assigned to their corresponding WHO diagnostic group with overall positive and negative predictive values of 89 and 96%, respectively. The efficiency of the PCA-based approach was particularly high among typical B-CLL, MCL and FL vs other B-CLPD cases. In summary, PCA-guided immunophenotypic classification of B-CLPD is a promising tool for standardized interpretation of tumor IP, their classification into well-defined entities and comprehensive evaluation of antibody panels

Genitourinary Pathology (Including Adrenal Gland)

Our aims in constructing the Genitourinary Pathology chapter are to describe neoplasms of the adrenal gland, urothelial tract, kidney, penis, prostate, and testis in a manner that is both useful for the practicing surgical pathologist and that may be used as a reference for all students of urologic pathology. Whereas the text and figures describe the salient morphologic, immunohistochemical, and molecular attributes for each tumor type and encompass the latest classification schemes, the narrative integrates the clinical and pathological findings that are commonly encountered during surgical pathology sign-out of these cases. Accordingly, it is our hope that this chapter will serve as a guide for both general and subspecialized pathologists in contemporary practice