The advent of fiberoptic endoscopy with biopsy has revolutionized procurement of specimens from deep sites. This has translated into more cytologic specimens whereby the material is limited and best handled by cytology laboratory staff. While the diagnosis of the pathologic process is of utmost importance, there is increasing expectation that the diagnosis be specific and accurate as not to require additional biopsy for initiation of treatment. This expectation has driven demand in immunohistochemical (IHC) and molecular studies conducted specifically on material processed as cytology specimens. The Clinical Laboratory Improvement Amendments of 1988 requires laboratories in the United States of America to verify the performance of patient tests. Due to varying laboratory practices with respect to validation of IHC assays, the College of American Pathologists introduced guidelines for analytic validation of IHC tests. These guidelines address how to perform validation by recommending the number of cases in the validation set, comparator concordance, and when to revalidate. The main thrust of the guidelines is based on formalin-fixed paraffin-embedded tissue with only one expert consensus opinion referring to validation of IHC tests on cytology specimens which delegates to the medical director, the determination of number of positive and negative cases to be tested. This article will outline how an academic center approaches validation of IHC studies performed on cytology cell block specimens using the College of American Pathologists guidelines. A stepwise approach from selection of antibodies to validate followed by building the validation panel and evaluating the stain results for concordance against the gold standard of histology tissue specimen will be described. A rationale for dealing with discordant results and future innovations will conclude the report.

Discovering the regulation of cancer-related gene is of great importance in cancer biology. Transcription factors and microRNAs are two kinds of crucial regulators in gene expression, and they compose a combinatorial regulatory network with their target genes. Revealing the structure of this network could improve the authors' understanding of gene regulation, and further explore the molecular pathway in cancer. In this article, the authors propose a novel approach graphical adaptive lasso (GALASSO) to construct the regulatory network in breast cancer. GALASSO use a Gaussian graphical model with adaptive lasso penalties to integrate the sequence information as well as gene expression profiles. The simulation study and the experimental profiles verify the accuracy of the authors' approach. The authors further reveal the structure of the regulatory network, and explore the role of feedforward loops in gene regulation. In addition, the authors discuss the combinatorial regulatory effect between transcription factors and microRNAs, and select miR-155 for detailed analysis of microRNA's role in cancer. The proposed GALASSO approach is an efficient method to construct the combinatorial regulatory network. It also provides a new way to integrate different data sources and could find more applications in meta-analysis problem.

Infl ammatory myofi broblastic tumor is rarely seen in the prostate. Most of prostatic tumors are benign. However, local aggressively invading the adjacent organs and recurrence are frequent. Rarely, the malignant transformation and metastasis occurs, especially in elderly patient. The defi nitive diagnosis in a small biopsy is challenging. The correct diagnosis preoperatively will help to avoid unnecessary radical prostatectomy. Interval follow up is recommended. Here we reported two cases of prostatic infl ammatory myofi broblastic tumor with literature review.How to cite this article: Dai D, Cai Q, Sutton A. Prostatic infl ammatory myofi broblastic tumor: 2-case report with literature review. Arch Pathol Clin Res. 2019; 3: 001-007. https://dx.

Rosai-Dorfman disease (RDD) is an idiopathic, benign proliferation of histiocytes that can be present in multiple organs such as lymph node, skin, soft tissue, orbit, central nerve system and bone; however, it rarely occurs in the breast. In general, RDD is a painless, firm and poorly defined lesion, which can radiologically mimic a breast cancer and is therefore an important consideration. The diagnosis of breast RDD is challenging, especially on a small biopsy specimen. We report a unique case of breast RDD with a literature review including common presentation, differential diagnosis, and recommended management. A high index of suspicion for this rare entity is essential to render a correct diagnosis, thereby avoiding unnecessary diagnostic tests and treatment.

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