Perspectives in pathologyMultisite tumor sampling: a new tumor selection method to enhance intratumor heterogeneity detection

•Intratumor heterogeneity (ITH) is an intrinsic characteristic to most neoplasms.•ITH may be hidden to pathologists and is responsible for most therapeutic failures.•Multisite tumor sampling is a new efficient alternative for pathologists.•Multisite tumor sampling outperforms classic sampling protocols in unveiling ITH without extra costs.

SummaryIntratumor heterogeneity (ITH) is increasingly being recognized as a highly complex process with high clinical impact that deserves special attention from practicing pathologists. The value of the ITH detection depends on the correctness of the pathologist's sampling. The goal of this review is 2-fold. On the one hand, we provide a basic scientific context for the practical pathologist's perspective. On the other hand, we encourage pathologists to adopt a more scientific and up-to-date approach to a key component of their daily work, namely, how to sample a tumor for reliable histological and molecular analysis. In particular, we review the consecutive steps of an efficient alternative to traditional approaches for detecting ITH: multisite tumor sampling. Notably, this type of sampling, based on a divide-and-conquer algorithm, is supported by scientific evidence showing its clinical applicability and practical advantages at no extra cost.