Do urinary bladder smooth muscle neoplasms show morphologic and immunophenotypic features of their uterine fumarate hydratase-deficient counterparts?

While the morphologic and immunophenotypic features of smooth muscle neoplasms of the uterus and skin have been well-described in relationship to fumarate hydratase (FH) deficiency (FHD), a potential association of urinary bladder smooth muscle tumors with FH tumor predisposition syndrome (FHTPS) has not been previously investigated. Given an index urinary bladder leiomyoma which showed some of the purported morphologic features seen in uterine FHD leiomyomas, we performed a multi-institutional search for bladder smooth muscle tumors to further evaluate a putative FHTPS association. Cases were re-reviewed for the presence of the following well-described FHD-associated cytomorphologic features: macronucleoli ("cherry red") surrounded by halo, isolated nuclear pleomorphism ("symplastic" nuclei), cytoplasmic eosinophilic globules, staghorn vasculature, alveolar-pattern edema, and chain-like distribution of smooth muscle fibers.

Succinate dehydrogenase deficient renal cell carcinoma frequently expresses GATA3 and L1CAM.

Succinate dehydrogenase deficient renal cell carcinoma (SDH RCC) is an uncommon, familial RCC that has overlapping morphologic features with other low grade eosinophilic tumors of the kidney. Although the diagnosis of SDH RCC relies on loss of SDHB by immunohistochemistry (IHC), not all laboratories have access to this antibody. GATA3 and L1CAM are increasingly utilized in the diagnosis of eosinophilic renal tumors; however, their expression profile has not been studied in SDH RCC.

MAPK1IP1L::TFE3-rearranged renal cell carcinoma: a novel fusion adding to the differential diagnosis of oncocytic renal neoplasms.

Beyond the more common TFE3 fusion partners PRCC, ASPSCR1, and SFPQ, additional less common fusion partners of TFE3-rearranged renal cell carcinoma (RCC) have been described. Herein, we present an example of TFE3-rearranged renal cell carcinoma harboring fusion partner MAPK1IP1L, a rare rearrangement with only one other reported tumor found in the literature. The currently reported TFE3-rearranged RCC demonstrates unique histological features compared to the previously reported tumor including dense eosinophilic cytoplasm and nuclear pseudoinclusions (corroborated by electron microscopic evaluation), with features not typically seen in other TFE3-rearranged RCCs.

The 1000 Mitoses Project: A Consensus-Based International Collaborative Study on Mitotic Figures Classification.

The identification of mitotic figures is essential for the diagnosis, grading, and classification of various different tumors. Despite its importance, there is a paucity of literature reporting the consistency in interpreting mitotic figures among pathologists. This study leverages publicly accessible datasets and social media to recruit an international group of pathologists to score an image database of more than 1000 mitotic figures collectively.

POU2F3-expressing intraepithelial small-cell carcinoma with mixed small-cell carcinoma and conventional-type urothelial carcinoma of the urinary bladder.

Based on lineage-specific transcription factors, small-cell neuroendocrine carcinoma (SmCC) of the urinary bladder has recently been subtyped into three molecular subtypes: ASCL1, NEUROD1 and POU2F3. The latter is a master transcriptional regulator of tuft cells (TCs) which are rare solitary cells found in various mucosal epithelia such as the gastrointestinal tract, but which have not been reported in the bladder. The POU2F3 subtype shows low or absent neuroendocrine marker expression.

Metastatic solid tumours to the penis: a clinicopathologic evaluation of 109 cases from an international collaboration.

Aims: To elucidate the spectrum of metastatic tumours to the penis and their clinicopathologic features.

Methods: The databases and files of 22 pathology departments from eight countries on three continents were queried to identify metastatic solid tumours of the penis and to characterize their clinical and pathologic features.

Results: We compiled a series of 109 cases of metastatic solid tumours that secondarily involved the penis.

ALK-rearranged renal cell carcinoma with TPM3::ALK gene fusion and review of the literature.

ALK-rearranged renal cell carcinoma (ALK-RCC) is a very rare novel molecularly defined entity in the recently published fifth edition of the World Health Organization classification of tumours. We describe a case of ALK-RCC in a 76-year-old female. The tumour was composed of discohesive rhabdoid cells and pleomorphic, multinucleated cells (equivalent to ISUP/WHO grade 4).

Tumor-Infiltrating Neutrophils after Neoadjuvant Therapy are Associated with Poor Prognosis in Esophageal Cancer.

Background: In esophageal cancer (EC), there is a paucity of knowledge regarding the interplay between the tumor immune microenvironment and response to neoadjuvant treatment and, therefore, which factors may influence outcomes. Thus, our goal was to investigate the changes in the immune microenvironment with neoadjuvant treatment in EC by assessing the expression of immune related genes and their association with prognosis.

Methods: We examined the transcriptome of paired pre- and post-neoadjuvant treated EC specimens.

Primary Prostatic Carcinoma With De Novo Diffuse Neuroendocrine Differentiation.

The 2016 World Health Organization classification of prostate cancer with neuroendocrine (NE) differentiation includes NE cells in usual prostate cancer, adenocarcinoma with Paneth cell-like NE differentiation, well-differentiated NE tumor (carcinoid), small cell NE carcinoma, and large cell NE carcinoma. In this article, we report a rare case of primary prostatic carcinoma with de novo diffuse NE differentiation presenting with bilateral hydronephrosis in a 79-year-old man. This case did not fit into any of the existing classifications.

Improving interpretation of biopsies during microsurgical testicular sperm exploration in azospermic patients: use of Davidson's fluid.

Histological interpretation of testicular biopsies in the investigation of infertility in men with azoospermia requires adequate tissue fixation to preserve the nuclear and cytoplasmic detail, as well as the architectural organisation of germ cells in different phases of maturation within seminiferous tubules. The aim of the study was to assess the histomorphological quality of testicular biopsies using Davidson's fluid (DF) as fixative and compare it to standard 10% neutral buffered formalin. Concurrent testicular biopsies from the same testis from patients undergoing microsurgical testicular sperm exploration (m-TESE) were separately fixed in DF and formalin and processed for histological examination.

Development of a silver in situ hybridisation based assay for the determination of ploidy status in molar pregnancy diagnosis.

The aim of this study was to establish a scoring method for ploidy analysis using silver in situ hybridisation (SISH) with a chromosome 17 centromere probe. SISH was performed using the Ventana chromosome 17 centromere probe on sections from formalin fixed, paraffin embedded archival cases of complete hydatidiform moles, partial hydatidiform moles and hydropic products of conception with previously established ploidy status (determined by flow cytometry or karyotyping). In order to determine ploidy status, a scoring method was developed based on both the average number of signals per nucleus (ASN) and the percentage of nuclei with three signals (N3S), enumerated in 50 villous cytotrophoblastic and/or stromal cells.

Post-traumatic pseudolipomas--a review and postulated mechanisms of their development.

Post-traumatic pseudolipomas develop in areas of the body that have been subjected to acute, severe, blunt trauma and chronic trauma. This study aimed to review the literature for reports of post-traumatic pseudolipomas on Medline and identify the possible mechanisms of their development. In the literature, 124 such cases were identified relating to case reports and case series; of these, 98 occurred in females and 26 in males.

A strange case of acute abdomen.

A 30-year-old male suffered from acute abdomen following duodenal biopsy taken at esophagogastroduodenoscopy (EGD). Exploratory laparotomy showed a large retroperitoneal hematoma arising from the second part of the duodenum that was then treated conservatively. To the authors' knowledge, this is the first case of extensive retroperitoneal hematoma following EGD.