HMGB1 released by mesothelial cells drives the development of asbestos-induced mesothelioma.

Asbestos is the main cause of malignant mesothelioma. Previous studies have linked asbestos-induced mesothelioma to the release of HMGB1 from the nucleus to the cytoplasm, and from the cytoplasm to the extracellular space. In the cytoplasm, HMGB1 induces autophagy impairing asbestos-induced cell death. Extracellularly, HMGB1 stimulates the secretion of TNFα. Jointly, these two cytokines kick-start a chronic inflammatory process that over time promotes mesothelioma development. Whether the main source of extracellular HMGB1 were the mesothelial cells, the inflammatory cells, or both was unsolved. This information is critical to identify the targets and design preventive/therapeutic strategies to interfere with asbestos-induced mesothelioma. To address this issue, we developed the conditional mesothelial HMGB1-knockout (Hmgb1ΔpMeso) and the conditional myelomonocytic-lineage HMGB1-knockout (Hmgb1ΔMylc) mouse models. We establish here that HMGB1 is mainly produced and released by the mesothelial cells during the early phases of inflammation following asbestos exposure. The release of HMGB1 from mesothelial cells leads to atypical mesothelial hyperplasia, and in some animals, this evolves over the years into mesothelioma. We found that Hmgb1ΔpMeso, whose mesothelial cells cannot produce HMGB1, show a greatly reduced inflammatory response to asbestos, and their mesothelial cells express and secrete significantly reduced levels of TNFα. Moreover, the tissue microenvironment in areas of asbestos deposits displays an increased fraction of M1-polarized macrophages compared to M2 macrophages. Supporting the biological significance of these findings, Hmgb1ΔpMeso mice showed a delayed and reduced incidence of mesothelioma and an increased mesothelioma-specific survival. Altogether, our study provides a biological explanation for HMGB1 as a driver of asbestos-induced mesothelioma.

SOX10-Internal Tandem Duplications and PLAG1 or HMGA2 Fusions Segregate Eccrine-Type and Apocrine-Type Cutaneous Mixed Tumors.

Cutaneous mixed tumors exhibit a wide morphologic diversity and are currently classified into apocrine and eccrine types based on their morphologic differentiation. Some cases of apocrine-type cutaneous mixed tumors (ACMT), namely, hyaline cell-rich apocrine cutaneous mixed tumors (HCR-ACMT) show a prominent or exclusive plasmacytoid myoepithelial component. Although recurrent fusions of PLAG1 have been observed in ACMT, the oncogenic driver of eccrine-type cutaneous mixed tumors (ECMT) is still unknown. The aim of the study was to provide a comprehensive morphologic, immunohistochemical, and molecular characterization of these tumors. Forty-one cases were included in this study: 28 cases of ACMT/HCR-ACMT and 13 cases of ECMT. After morphologic and immunohistochemical characterization, all specimens were analyzed by RNA sequencing. By immunohistochemistry, all cases showed expression of SOX10, but only ACMT/HCR-ACMT showed expression of PLAG1 and HMGA2. RNA sequencing confirmed the presence of recurrent fusion of PLAG1 or HMGA2 in all cases of ACMT/HCR-ACMT, with a perfect correlation with PLAG1/HMGA2 immunohistochemical status, and revealed internal tandem duplications of SOX10 (SOX10-ITD) in all cases of ECMT. Although TRPS1::PLAG1 was the most frequent fusion, HMGA2::WIF1 and HMGA2::NFIB were detected in ACMT cases. Clustering analysis based on gene expression profiling of 110 tumors, including numerous histotypes, showed that ECMT formed a distinct group compared with all other tumors. ACMT, HCR-ACMT, and salivary gland pleomorphic adenoma clustered together, whereas myoepithelioma with fusions of EWSR1, FUS, PBX1, PBX3, POU5F1, and KLF17 formed another cluster. Follow-up showed no evidence of disease in 23 cases across all 3 tumor types. In conclusion, our study demonstrated for the first time SOX10-ITD in ECMT and HMGA2 fusions in ACMT and further refined the prevalence of PLAG1 fusions in ACMT. Clustering analyses revealed the transcriptomic distance between these different tumors, especially in the heterogenous group of myoepitheliomas.

Wnt/ß-Catenin-Activated Nonpilomatrical Carcinoma of the Skin: A Case Series.

Among skin epithelial tumors, recurrent mutations in the APC/CTNNB1 genes resulting in activation of the Wnt/ß-catenin pathway have been reported predominantly in neoplasms with matrical differentiation. In the present study, we describe the morphologic, immunohistochemical, and genetic features of 16 primary cutaneous carcinomas harboring mutations activating the Wnt/ß-catenin pathway without evidence of matrical differentiation, as well as 4 combined tumors in which a similar Wnt/ß-catenin-activated carcinoma component was associated with Merkel cell carcinoma (MCC) or pilomatrical carcinoma. Among the pure tumor cases, 6 of 16 patients were women with a median age of 80 years (range, 58-98 years). Tumors were located on the head and neck (n = 7, 44%), upper limb (n = 4, 25%), trunk (n = 3, 18%), and leg (n = 2, 13%). Metastatic spread was observed in 4 cases resulting in death from disease in 1 patient. Microscopically, all cases were poorly differentiated neoplasms infiltrating the dermis and/or subcutaneous tissue. In 13 cases, solid "squamoid" areas were associated with a basophilic component characterized by rosette/pseudoglandular formation resulting in a biphasic appearance. Three specimens consisted only of poorly differentiated carcinoma lacking rosette formation. Immunohistochemical studies showed frequent expression of EMA (100%), BerEP4 (100%), cytokeratin 7 (94%), chromogranin A (44%), synaptophysin (82%), and cytokeratin 20 (69%). Complete loss of Rb expression was observed in all but 1 case. Nuclear ß-catenin and CDX2 expressions were detected in all cases. Recurrent pathogenic somatic mutations were observed in APC (60%), CTNNB1 (40%), and RB1 (n = 47%). Global methylation analysis confirmed that cases with rosette formation constituted a homogeneous tumor group distinct from established skin tumor entities (pilomatrical carcinoma, MCC, and squamous cell carcinoma), although the 3 other cases lacking such morphologic features did not. In addition, we identified 4 combined neoplasms in which there was a component showing a similar poorly differentiated rosette-forming carcinoma demonstrating Rb loss and ß-catenin activation associated with either MCC (n = 3) or pilomatrical carcinoma (n = 1). In conclusion, we describe a distinctive neoplasm, for which we propose the term "Wnt/ß-catenin-activated rosette-forming carcinoma," morphologically characterized by the association of rosette formation, squamous and/or neuroendocrine differentiation, diffuse CDX2 expression, Rb loss, and mutations in CTNNB1/APC genes.

Laparoscopic Colorectal Surgery with Anatomical Recognition with Artificial Intelligence Assistance for Nerves and Dissection Layers.

BACKGROUND: In digestive tract surgery, dissection of an avascular space consisting of loose connective tissue (LCT) appearing by countertraction improves oncological outcomes and reduces complications.1-3 Kumazu et al.4 described a deep learning approach that automatically segments LCT to help surgeons.4 During left colorectal surgery, lumbar splanchnic, hypogastric, and pelvic visceral nerve injuries cause sexual dysfunction and/or urinary issues.5 As nerve preservation is critical for functional preservation, the AI model Kumazu reported is named Eureka (Anaut Inc., Tokyo, Japan) and was developed to separate nerves automatically. The educative efficacy of intraoperative nerve visualization has been described.6 Artificial intelligence (AI) assisted navigation is expected to aid in the anatomical recognition of nerves and the safe dissection layers surrounding nerves in the future. METHODS: We used Eureka as an educational tool for surgeons' training during laparoscopic colorectal surgery. The laparoscopic system used was Olympus VISERA ELITE3 (Tokyo, Japan). RESULTS: Total mesorectal excision (TME) was safely performed with nerve preservation. No postoperative complications occurred. Automatic segmentation and highlighting of LCT in the dissected layers, lumbar splanchnic, hypogastric, and pelvic visceral nerves (S3, S4), were performed in real time. CONCLUSIONS: In colorectal cancer surgery, the nerves are vital anatomical structures serving as landmarks for dissection. Lumbar splanchnic, hypogastric, and pelvic visceral nerve injuries (S3, S4) cause sexual dysfunction or urinary disorders.5 Nerve preservation is important for functional preservation. AI-assisted navigation methods are noninvasive, user-friendly, and expected to improve in accuracy in the future. They have the potential to develop nerve-guided TME.

Nesprin1 deficiency is associated with poor prognosis of renal cell carcinoma and resistance to sunitinib treatment.

INTRODUCTION: Nuclear envelope spectrin repeat protein (Nesprin) 1 encoded by SYNE1, crucially regulates the morphology and functions of the cell. Mutations in the SYNE1 gene are associated with various diseases; however, their significance in renal cell carcinoma (RCC) remains unknown. In this study, we have investigated the association of SYNE1/Nesprin1 with the progression and prognosis of clear cell RCC (ccRCC). METHODS: In silico analyses of publicly available datasets of patients with RCC were performed. Based on the cohort data, Nesprin1 expression in nephrectomized tissue samples acquired from patients with ccRCC was analyzed using immunohistochemical staining. The invasion, migration, and proliferation of the SYNE1-knockdown human RCC cell lines were analyzed in vitro; moreover, RNA sequencing and Gene Set Enrichment Analysis were conducted to study the molecular mechanism underlying the association of SYNE1/Nesprin1 with prognosis of RCC. RESULTS: Patients with RCC-associated SYNE1 gene mutations exhibited significantly worse overall and progression-free survivals. Patients with Nesprin1-negative ccRCC tumors exhibit significantly poorer overall, cancer-specific, and recurrence-free survival rates than those recorded in the Nesprin1-positive group. SYNE1 knockdown enhanced the invasion and migration of RCC cells, however, it did not influence the proliferation of cells. RNA sequencing and Gene Set Enrichment Analysis revealed that SYNE1 knockdown significantly altered the expression of genes associated with oxidative phosphorylation. Consistently, patients with RCC exhibiting low SYNE1 expression, who were treated with the vascular endothelial growth factor receptor inhibitor sunitinib, had worse progression-free survival. CONCLUSIONS: The results indicate that the expression of SYNE1/Nesprin1 and SYNE1 mutations in patients with RCC are closely linked to their prognosis and responsiveness to sunitinib treatment.

NRASQ61R-driven atypical melanocytic tumor with blue nevus-like morphology: A case report.

NRAS Q61 mutations are driver genetic alterations associated with common melanocytic nevi. Herein, we describe a case of NRAS-mutant melanocytic tumor with a blue nevus-like morphology. A 71-year-old Japanese man presented with a 4.6-mm nodule on his back. Histopathological examination revealed a dense distribution of spindle-shaped melanocytes in the upper dermis and a sparse distribution of dendritic melanocytes in the mid-dermis. The vertical periadnexal extension reached the deep dermis at the center of the tumor. A small junctional component, hyperpigmentation, sclerotic stroma, mild nuclear atypia, and a few mitotic figures were observed. Immunohistochemical examination revealed no PRAME expression and preserved p16 expression. Diffuse RASQ61R immunoreactivity was observed in these tumor cells. Nuclear ß-catenin expression was not observed. Targeted RNA sequencing revealed two mutations, NRAS c.182A>G (Q61R) and FGFR2 c.-157A>G, but no other pathogenic alterations such as BRAF, GNAQ, GNA11, CTNNB1, PRKAR1A, or IDH1 mutations or kinase gene fusions. The histopathology fits that of compound-type blue nevus, which is called "Kamino nevus"; however, this tumor was genetically considered to be on the spectrum of conventional acquired melanocytic nevi but not on that of blue nevi. Morphologically, NRAS-driven melanocytic nevi resemble blue nevi without IDH1R132C coexistence.

Apocrine carcinoma with marked sebocyte-like cytological features: A report of two cases.

Apocrine carcinoma cases with sebaceous differentiation have not been reported and can be misdiagnosed as sebaceous carcinoma. We present two cases of apocrine carcinoma with marked sebocyte-like cytological features. Tumors were observed in the left axilla of a 68-year-old man (Case 1) and the right axilla of a 72-year-old man (Case 2). Both patients presented with multiple lymph node metastases. Histopathology revealed densely distributed solid nests of tumor cells containing foamy cytoplasm and enlarged round nuclei with prominent nucleoli. The tumor cells diffusely expressed adipophilin, PRAME (cytoplasmic pattern), androgen receptor, BerEP4, and GCDFP15 but did not express p63 in both cases. PIK3CA E726K and H1047R mutations were detected in Cases 1 and 2, respectively. Tumor location in the axilla, the presence of eosinophilic granular cytoplasm, prominent nucleoli, and PIK3CA mutations, immunoreactivity for BerEP4 and GCDFP15, and lack of p63 immunoexpression findings matched apocrine carcinoma characteristics, but not sebaceous carcinoma. Thus, apocrine carcinoma can demonstrate intracytoplasmic lipid accumulation and rarely exhibit sebocyte-like cytological features. Apocrine carcinoma should be distinguished from sebaceous carcinoma due to the former's higher metastatic potential and lack of association with Muir-Torre syndrome.

Comprehensive genomic profiling testing in Japanese castration-resistant prostate cancer patients: results of a single-center retrospective cohort study.

OBJECTIVE: Comprehensive genomic profiling testing using a hybrid-capture next-generation sequencing is commonly used in clinical practice to employ precision medicine in cancer treatment worldwide. In this study, we aimed to analyze the profiles obtained using comprehensive genomic profiling testing that was performed in Japanese castration-resistant prostate cancer patients and to discuss the genetic findings in a real-world setting. METHODS: A total of 60 cases and 57 castration-resistant prostate cancer patients underwent comprehensive genomic profiling testing between 1 January 2021 and 31 December 2022. Four types of comprehensive genomic profiling testing were selected, and clinically significant cancer-specific gene alterations were identified. RESULTS: The median age of patients was 74 years, and the median prostate-specific antigen value at the time of submission was 18.6 ng/ml. Fifty-seven (95%) of 60 cases were metastatic castration-resistant prostate cancers, and 3 cases (5%) were non-metastatic. Among all genetic alterations, androgen-receptor alteration was the most frequently detected in 17 cases (28.3%), followed by 15 cases of TP53 (25.0%), 14 cases of CDK12 (23.3%), 10 cases of phosphatase and tensin homolog (16.7%) and 9 cases of ATM (15.0%) mutations. A total of 13 patients (21.7%) received systemic therapy according to the comprehensive genomic profiling testing results. Overall, the survival rate was significantly greater in the group treated through systemic therapy based on comprehensive genomic profiling testing compared with the group without new therapeutic treatment (P = 0.041). CONCLUSIONS: Comprehensive genomic profiling testing is recommended in castration-resistant prostate cancer patients identified as resistant to standard therapy as this can provide a new therapeutic option.

Loss of p16 Immunoexpression and Deletions of CDKN2A in the Progression of Extramammary Paget Disease: An Immunohistochemical and Genetic Study of 24 Invasive/Metastatic Cases.

ABSTRACT: Information regarding the genetic alterations in extramammary Paget disease (EMPD) is scarce. This study investigated the significance of CDKN2A and MTAP alterations in EMPD progression using immunohistochemistry and panel DNA sequencing. In total, 24 invasive/metastatic EMPD cases were included in this study. The immunoexpression of p16 and MTAP in the primary in situ, primary invasive, and metastatic tumor components was evaluated. Panel DNA sequencing was performed for metastatic tumor components in 5 of the 24 cases. Immunoexpression of p16 in the in situ tumor component was at least partially preserved in all 19 tested cases (100%). By contrast, the invasive tumor component was diffusely or partially lost in 18 (81.8%) of 22 tested cases. Regarding the foci of lymph node metastasis, 13 (81.2%) of the 16 patients showed a significant loss of p16 expression. Loss of MTAP immunoexpression was observed less frequently compared with the loss of p16 expression. CDKN2A homozygous deletions were confirmed in all 5 tested cases by sequencing, whereas MTAP deletions were detected in only 2 cases. In conclusion, p16 expression loss and CDKN2A deletions can be frequently seen in invasive/metastatic cases of EMPD.

Clinical characteristics and predictors of long-term postoperative urinary incontinence in patients treated with robot-assisted radical prostatectomy: A propensity-matched analysis.

OBJECTIVES: This study aimed to elucidate the clinical characteristics and predictors of long-term postoperative urinary incontinence (PUI) after robot-assisted radical prostatectomy (RARP). METHODS: This study included patients who underwent RARP at our institution and were stratified into PUI (≥1 pad/day) and continence (0 pad/day) groups at 60 months after RARP. A propensity score-matched analysis with multiple preoperative urinary status (Expanded Prostate Cancer Index Composite urinary subdomains, total International Prostate Symptom Score (IPSS), and IPSS-quality of life scores) was performed to match preoperative urinary status in these groups. Serial changes in urinary status and treatment satisfaction preoperatively and until 60 months after RARP were compared, and predictors of long-term PUI were assessed using multivariate logistic regression analysis. RESULTS: A total of 228 patients were included in the PUI and continence groups (114 patients each). Although no significant difference in preoperative urinary status was observed between the two groups, the postoperative urinary status significantly worsened overall in the PUI group than in the continence group. Treatment satisfaction was also significantly lower in the PUI group than in the continence group from 12 to 60 months postoperatively. Multivariate logistic regression analysis revealed that age (≥70 years) and biochemical recurrence (BCR) were significant predictors of the long-term PUI group (p < 0.05). CONCLUSIONS: Patients with long-term PUI had poor overall postoperative urinary status and lower treatment satisfaction than the continence group. Considering the age and risk of BCR is important for predicting long-term PUI when performing RARP.

Preoperative high serum total testosterone levels predict preserved postoperative sexual function in patients after nerve-sparing robot-assisted radical prostatectomy.

OBJECTIVE: To assess the association among preoperative total testosterone levels, postoperative sexual function, and prognosis after robot-assisted radical prostatectomy. METHODS: Patients who underwent robot-assisted radical prostatectomy in our institution were included in the study. Based on preoperative total testosterone levels, they were divided into low (<3.0 ng/mL) and high (≥3.0 ng/mL) total testosterone groups. Sexual function was evaluated using the International Index of Erectile Function scores, Expanded Prostate Cancer Index Composite scores, and the potency rate from preoperatively to 12 months after surgery. Oncological outcomes were evaluated based on biochemical recurrence. RESULTS: Out of 233 patients included, no significant difference in sexual function was found between the high (n = 183) and the low (n = 50) total testosterone groups at any point before or after surgery. However, in nerve-sparing cases, preservation in postoperative sexual function was observed only in the high total testosterone group (International Index of Erectile Function scores and Expanded Prostate Cancer Index Composite sexual function scores, at any point after surgery, p < 0.05; potency rate, at 3, 6, and 12 months after surgery; p < 0.05). Additionally, the high total testosterone group showed better biochemical recurrence-free survival than the low total testosterone group (p = 0.008). CONCLUSIONS: In the high total testosterone group, preservation in sexual function was observed after the nerve-sparing procedure, while the biochemical recurrence rate was low. Therefore, patients with high levels of total testosterone may be advised to consider nerve-sparing interventions.

Prognostic outcomes in patients with metastatic renal cell carcinoma receiving second-line treatment with tyrosine kinase inhibitor following first-line immune-oncology combination therapy.

OBJECTIVES: This study aimed to assess the prognostic outcomes in mRCC patients receiving second-line TKI following first-line IO combination therapy. METHODS: This study retrospectively included 243 mRCC patients receiving second-line TKI after first-line IO combination therapy: nivolumab plus ipilimumab (n = 189, IO-IO group) and either pembrolizumab plus axitinib or avelumab plus axitinib (n = 54, IO-TKI group). Oncological outcomes between the two groups were compared, and prognostication systems were developed for these patients. RESULTS: In the IO-IO and IO-TKI groups, the objective response rates to second-line TKI were 34.4% and 25.9% (p = 0.26), the median PFS periods were 9.7 and 7.1 months (p = 0.79), and the median OS periods after the introduction of second-line TKI were 23.1 and 33.5 months (p = 0.93), respectively. Among the several factors examined, non-CCRCC, high CRP, and low albumin levels were identified as independent predictors of both poor PFS and OS by multivariate analyses. It was possible to precisely classify the patients into 3 risk groups regarding both PFS and OS according to the positive numbers of the independent prognostic factors. Furthermore, the c-indices of this study were superior to those of previous systems as follows: 0.75, 0.64, and 0.61 for PFS prediction and 0.76, 0.70, and 0.65 for OS prediction by the present, IMDC, and MSKCC systems, respectively. CONCLUSIONS: There were no significant differences in the prognostic outcomes after introducing second-line TKI between the IO-IO and IO-TKI groups, and the histopathology, CRP and albumin levels had independent impacts on the prognosis in mRCC patients receiving second-line TKI, irrespective of first-line IO combination therapies.

BACH1 promotes clear cell renal cell carcinoma progression by upregulating oxidative stress-related tumorigenicity.

The carcinogenesis and progression of renal cell carcinoma (RCC), a heterogeneous cancer derived from renal tubular epithelial cells, is closely related to oxidative stress responses (OSRs). Oxidative stress responses participate in various biological processes related to the metabolism and metastatic potential of cancer such as inflammation, epithelial-mesenchymal transition (EMT), and angiogenesis. In this study, we investigated the role of broad complex-tramtrack-bric-a-brac and cap 'n' collar homology 1 (BACH1), a key transcription factor for OSRs, in clear cell RCC (ccRCC) development and prognosis. The poor prognosis and elevation of serum inflammation markers in nephrectomized ccRCC patients were correlated with the intratumor expression of BACH1 accompanied by a downregulation of heme oxygenase-1. BACH1 contributes to the invasion and migration abilities of RCC cell lines without affecting their proliferation in vitro. In contrast, BACH1 contributes to tumor progression in vivo, in relation to OSRs with the activation of EMT-related pathways. BACH1 involvement in other OSR-linked pathways, including inflammatory responses, angiogenesis, and mTOR signaling, was further revealed by RNA sequencing analysis of BACH1-knockdown cells. In conclusion, the crucial role of BACH1 in the pathogenesis and poor prognosis of ccRCC through the promotion of OSRs is suggested.

A Japanese case of familial malignant melanoma with germline CDK4 variant incidentally diagnosed by cancer genome profiling.

Familial malignant melanoma (FMM) is a hereditary tumor that is quite rare in Japan; to date, the germline CDK4 variant has scarcely been reported around the world. Thus, we report on a woman with FMM who developed salivary gland cancer, for which a germline pathogenic variant of CDK4 was incidentally identified through comprehensive genomic profiling. She had a history of multiple atypical nevi and a facial melanoma since her 30 s and multiple family histories of melanoma; however, none of her relatives were aware of its heredity. Genetic counseling and skin surveillance were performed. Precision medicine for cancer can discover this rare genetic syndrome and provides us with the opportunity to manage the health of patients and their relatives.

Recurrent PAK2 rearrangements in poroma with folliculo-sebaceous differentiation.

AIMS: Poroma is a benign adnexal neoplasm with differentiation towards the upper portion of the sweat gland apparatus. In 2019, Sekine et al. demonstrated recurrent YAP1::MAML2 and YAP1::NUTM1 fusion in poroma and porocarcinoma. Follicular, sebaceous and/or apocrine differentiation has been reported in rare cases of poroma and whether these tumours constitute a variant of poroma or represent a distinctive tumour is a matter to debate. Herein we describe the clinical, immunophenotypic, and molecular features of 13 cases of poroma with folliculo-sebaceous differentiation. METHODS AND RESULTS: Most of the tumours were located on the head and neck region (n = 7), and on the thigh (n = 3). All presented were adults with a slight male predilection. The median tumour size was 10 mm (range: 4-25). Microscopically, lesions displayed features of poroma with nodules of monotonous basophilic cells associated with a second population of larger eosinophilic cells. In all cases, ducts and scattered sebocytes were identified. Infundibular cysts were present in 10 cases. In two cases high mitotic activity was noted, and in three cases cytologic atypia and areas of necrosis were identified. Whole transcriptome RNA sequencing demonstrated in-frame fusion transcripts involving RNF13::PAK2 (n = 4), EPHB3::PAK2 (n = 2), DLG1::PAK2 (n = 2), LRIG1::PAK2 (n = 1), ATP1B3::PAK2 (n = 1), TM9SF4::PAK2 (n = 1), and CTNNA1::PAK2 (n = 1). Moreover, fluorescence in situ hybridisation (FISH) analysis revealed PAK2 rearrangement in an additional case. No YAP1::MAML2 or YAP1::NUTM1 fusion was detected. CONCLUSION: Recurrent fusions involving the PAK2 gene in all analysed poroma with folliculo-sebaceous differentiation in this study confirms that this neoplasm represents a separate tumour entity distinct from YAP1::MAML2 or YAP1::NUTM1 rearranged poromas.

Recurrent FOXK1::GRHL and GPS2::GRHL fusions in trichogerminoma.

We report 21 cases of trichogerminoma harbouring previously undescribed FOXK1::GRHL1/2 or GPS2::GRHL1/2/3 in-frame fusion transcripts. Microscopic examination of a preliminary set of five cases revealed well-delimitated tumours located in the dermis with frequent extension to the subcutaneous tissue. Tumours presented a massive and nodular architecture and consisted of a proliferation of basaloid cells. A biphasic pattern sometime resulting in tumour cell nests ('cell balls') was present. Immunohistochemistry demonstrated the expression of cytokeratins (CKs) 15, 17, and PHLDA1. In addition, numerous CK20-positive Merkel cells were detected. RNA sequencing (RNA-seq) revealed a FOXK1::GRHL1 chimeric transcript in three cases and a FOXK1::GRHL2 fusion in two cases. In a second series for validation (n = 88), FOXK1::GRHL1/2 fusion transcripts were detected by RT-qPCR or FISH in an additional 12 trichogerminomas and not in any other follicular tumour entities or basal cell carcinoma cases (n = 66). Additional RNA-seq analysis in trichogerminoma cases without detected FOXK1::GRHL1/2 rearrangements revealed GPS2::GRHL1 fusion transcripts in two cases, GPS2::GRHL2 in one case, and GPS2::GRHL3 fusion transcript in one case. Therefore, our study strongly suggests that GRHL1/2/3 gene rearrangements might represent the oncogenic driver in trichogerminoma, a subset of follicular tumours characterized by immature features and numerous Merkel cells. © 2022 The Pathological Society of Great Britain and Ireland.

Preoperative fluorescent clip marking vs. India ink tattooing for tumor identification during colorectal surgery.

PURPOSE: Identifying tumor location is important in colorectal tumor resection. Preoperative endoscopic India ink marking is a widespread practice, but local injection of ink is an unstable procedure. Although it is often invisible, the ink may be sprayed into the peritoneal cavity and contaminate the surgical field. At our hospital, we introduced fluorescent clip marking (FCM) using the Zeoclip FS®, an endoscopic clip developed using near-infrared fluorescent resin. We tested the usefulness of FCM by retrospectively comparing cases in which FCM was used with cases in which conventional ink marking was used. METHODS: We enrolled 305 patients with colorectal tumors who underwent colorectal surgery after preoperative marking from January 2017 to April 2022. We classified the patients into the FCM group (86 patients) and the India ink tattoo group (219 patients). Endoscopic marking was completed in the FCM group by the day before surgery, and fluorescence was evaluated during surgery with a fluorescent laparoscopic system. Patient backgrounds, marking visibility, adverse effects, and early postoperative results were retrospectively compared between groups. RESULTS: Marking was visually confirmed in 80 patients in the FCM group (93.02%) and in 166 patients in the India ink tattoo group (75.80%) (p = 0.0006). In the group with India ink tattoos, contamination of the surgical field was observed in seven cases (3.20%). No adverse events were observed in the FCM group. CONCLUSION: In colorectal surgery, FCM provides better visibility than the conventional India ink tattooing method and is a simple and safe marking method. CLINICAL TRIAL REGISTRATION: Examination of fluorescence navigation for laparoscopic colorectal cancer surgery. Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2020-3. https://kawaguchi-mmc.org/wp-content/uploads/clinicalresearch-r02.pdf .

Transcriptional repressor GATA binding 1 (TRPS1) immunoexpression in normal skin tissues and various cutaneous tumors.

BACKGROUND: Transcriptional repressor GATA binding 1 (TRPS1) is a transcription factor recently shown to play a role in the development of breast and liver cancer. Here, we evaluate TRPS1 immunoexpression in normal skin tissues and various cutaneous tumors. METHODS: TRPS1 immunohistochemistry was performed in 109 cases of primary cutaneous tumors and 19 cases of metastatic carcinomas. TRPS1 expression was also evaluated in the normal skin tissues. RESULTS: The normal epidermis was TRPS1-. In contrast, the eccrine apparatus, epithelial compartment of the hair follicles, hair papilla, sebaceous glands, and anogenital mammary-like glands were TRPS1+. In primary cutaneous tumors, TRPS1 positivity varied in poroma (2/3), nodular hidradenoma (4/5), spiradenoma (4/4), cutaneous mixed tumor (5/5), trichilemmal cyst (7/8), proliferating trichilemmal tumor (1/3), pilomatricoma (9/9), sebaceoma (2/5), extramammary Paget disease (13/13), sebaceous carcinoma (2/2), actinic keratosis (3/10), Bowen disease (7/12), and squamous cell carcinoma (1/5) cases. All cases of seborrheic keratosis, basal cell carcinoma, Merkel cell carcinoma, and malignant melanoma were TRPS1-. All metastatic breast carcinoma cases (8/8) were highly positive for TRPS1, while all but one of the other metastatic tumor cases were TRPS1-. CONCLUSIONS: TRPS1 immunoexpression was observed in several skin appendages and cutaneous tumors.

YAP1::MAML2 fusions in poromatosis: A report of two patients.

Poromatosis is a rare condition characterized by the development of multiple poromas, mainly reported in patients with a history of malignancy. Recently, frequent YAP1::MAML2 and YAP1::NUTM1 fusions have been described in poromas and porocarcinomas. To date, the molecular features of poromatosis have been investigated in one patient only, wherein the poromas harbored YAP1::MAML2 fusions. Herein, we present two additional cases of poromatosis with YAP1::MAML2 fusions. Case 1: An 81-year-old woman presented with nine papules on the scalp, trunk, and extremities persisting for a year. She had a history of breast cancer, with no information on the treatment. Seven papules were excised. Case 2: A 65-year-old woman presented with 21 lesions on her trunk and lower extremities persisting for 2 years. She had been diagnosed with breast cancer 11 years prior and had undergone partial mastectomy, radiotherapy, chemotherapy, and endocrine therapy. Four lesions were excised. All 11 lesions in both patients were histopathologically similar: anastomosing cords and strands extending from the epidermis, and poroid and cuticular cell proliferation with interspersed small ducts. The tumors showed diffuse nuclear expression of YAP1 N-terminus and loss of YAP1 C-terminus expression. No lesions showed NUT immunopositivity. Sanger sequencing identified YAP1::MAML2 fusions in the poromas of both patients.

Clinicopathologic and genetic characterization of invasive melanoma with BRAF V600K mutation: A study of 16 cases.

BACKGROUND: The clinicopathologic and genetic features of cutaneous melanoma with a BRAF V600K mutation are not well-known. We aimed to evaluate these characteristics in comparison with those associated with BRAF V600E. METHODS: Real-time polymerase chain reaction (PCR) and/or the MassARRAY® system were used to detect BRAF V600K in 16 invasive melanomas and confirm BRAF V600E in another 60 cases. Immunohistochemistry and panel next-generation sequencing were used to evaluate protein expression and tumor mutation burden, respectively. RESULTS: The median age of melanoma patients harboring the BRAF V600K mutation (72.5 years) was higher than those with the BRAF V600E (58.5 years). The two groups also differed in sex (13/16 [81.3%] male in the V600K group vs. 23/60 [38.3%] in V600E) and in the frequency of scalp involvement (8/16 [50.0%] in V600K vs. 1/60 [1.6%] in V600E). The clinical appearance was similar to a superficial spreading melanoma. Histopathologically, non-nested lentiginous intraepidermal spread and subtle solar elastosis were observed. One patient (1/13, 7.7%) had a pre-existing intradermal nevus. Diffuse PRAME immunoexpression was seen in only one (14.3%) of seven tested cases. Loss of p16 expression was observed in all 12 cases (100%) analyzed. The tumor mutation burden was 8 and 6 mutations/Mb in the two tested cases. CONCLUSIONS: Melanoma carrying the BRAF V600K mutation showed the predominance on the scalp of elderly men, lentiginous intraepidermal growth, subtle solar elastosis, possible existence of intradermal nevus component, frequent loss of p16 immunoexpression, limited immunoreactivity for PRAME, and intermediate tumor mutation burden.