Undifferentiated and dedifferentiated urological carcinomas: lessons learned from the recent developments

SWI/SNF-deficient Malignancies: Optimal Candidates for Immune-oncological Therapy?

Inactivation of different subunits of the SWItch/sucrose nonfermentable (SWI/SNF) chromatin remodeling complex has emerged as one of the most frequent genetic pathways driving a variety of neoplasms of diverse histogenesis, originating in different organs. With few exceptions, most SWI/SNF-deficient malignancies pursue a highly aggressive clinical course resulting in widespread disease dissemination either at or soon after diagnosis, ultimately causing patients' death soon after diagnosis, despite the apparently curative treatment intention. To date, no satisfactorily effective systemic chemotherapy has been established for treating these diseases. This disappointing finding underlines the urgent need for an effective systemic therapy that would enable sufficient intermediate to long-term disease control. Recently, SWI/SNF-deficiency has increasingly emerged as pivotal in cancer immunogenicity and hence a promising biomarker predicting response to immune-checkpoint inhibition therapy utilizing several recently established drugs. This review summarizes the most recent literature on this topic with emphasis on the entities that most likely represent suitable candidates for immune therapy.

Scoring Systems for Immunohistochemistry in Urothelial Carcinoma

Immunohistochemistry is widely used in diagnostic and scientific analysis of urothelial carcinoma. Objective interpretation of staining results is mandatory for accuracy and comparability in diagnostic and therapeutic patient care as well as research.Herein we summarize and explain standardized microscopic evaluation and scoring approaches for immunohistochemical stainings. We focus on commonly used and generally feasible approaches for different cellular compartments and comment on their utility in diagnostics and research practice.

The Histologic Diversity of Chromophobe Renal Cell Carcinoma With Emphasis on Challenges Encountered in Daily Practice

Chromophobe renal cell carcinoma (ChRCC) is the third most common renal cell carcinoma in adults. The aim of this review is to provide a comprehensive overview highlighting the broad morphologic spectrum of ChRCC, and offer a practical approach for handling cases in daily practice. For the purpose of this review, we classify ChRCC subtypes as (1) classic, (2) eosinophilic, (3) sarcomatoid, and (4) other rare patterns. The concept of eosinophilic ChRCC has significantly evolved, yet it still is one of the major diagnostic challenges pathologists face in routine practice due to its morphologic overlap with renal oncocytoma. Rare patterns of ChRCC have been described over the last few decades, showing a wide histologic spectrum including those with adenomatoid microcystic pigmented, multicystic, neuroendocrine, small cell, and papillary features. ChRCC represents a heterogenous group of neoplasms, demonstrating varied but unique morphologic and genetic profiles. Although the field of ChRCC knowledge is still evolving, rare patterns can present diagnostic challenges if they are not known to pathologists and/or clinicians. Proper and generous tumor sampling along with careful histologic examination allow for recognition of these rare morphologies. The role of routine molecular testing appears to be limited. From a clinical management standpoint, the rare patterns of ChRCC seem to have no definite clinical implications at present and likely can be managed similarly to usual ChRCC. Finally, we will discuss distinctive novel/emerging renal neoplasms previously considered under the spectrum of ChRCC, low-grade oncocytic renal tumor and eosinophilic vacuolated tumor, with regard to their current significance and implications for future classification strategies.