Solid Pattern Research Articles

Bladder Lymphoma. Presentation of clinical case

Introduction: lymphomas develop in lymphoid tissue located in lymph nodes and in dissimilar organs of the human body. They are malignant tumors located in the lymphoid tissue with a low incidence in the genitourinary tract as the primary site; among them, those of the bladder are uncommon. Primary bladder lymphomas present an indistinguishable clinical-radiological pattern, of solid growth and with characteristics similar to urothelial carcinoma. Objective: to present a clinical case, with a diagnosis of primary bladder lymphoma treated in the Oncology service of the “Abel Santamaría Cuadrado” General Teaching Hospital in Pinar del Río. Case presentation: patient, 58 years old, male, white, relative health history; In February 2020, he went to the clinic due to bleeding in his urine, urinary urgency, droplet urination, as well as weight loss of more than 15 lbs. and evening fever. He was evaluated by the urology service, which suspected urothelial carcinoma of the bladder, which led to a systematic diagnosis that determined infiltration of the bladder wall by intermediate B cell non-Hodgkin lymphoma. Conclusions: the diagnosis in these cases is determined by immunohistochemistry studies and tumor monoclonality demonstrated by molecular biology techniques. Primary bladder lymphomas have a solid growth pattern similar to that of urothelial carcinoma. The choice for treatment consists of a regimen consisting of CHOP chemotherapy (cyclophosphamide, vincristine, prednisone, doxorubicin) combined with the anti-CD20 monoclonal antibody rituximab. We present a case of infradiaphragmatic intermediate B cell non-Hodgkin lymphoma with extralymphatic involvement of the bladder

Elucidating the nature of acinic cell carcinoma of the breast with high-grade morphology: evidence from case report

BackgroundAcinic cell carcinoma (AciCC) of the breast is a rare subtype of breast cancer. It was considered a low-grade triple-negative breast cancer (TNBC) with the potential to progress or transform into a high-grade lesion because of the molecular similarities with conventional aggressive TNBC in several genetic studies. Microscopically, the coexistence of classical low-grade and high-grade triple-negative components in breast AciCC is not uncommon. However, there is a scarcity of research on the comparative histopathological and genetic aspects of both components.Case presentationA 34-year-old woman with a nontender mass in the upper outer quadrant of the left breast was initially diagnosed with a malignant small round cell tumor (undifferentiated or poorly differentiated carcinoma) based on a preoperative biopsy, which was later identified as breast AciCC with a high-grade solid component. Left breast-conserving surgery with sentinel lymph node biopsy was performed. Microscopically, the breast AciCC consisted of a classical acinic component and a high-grade component. The latter demonstrated a solid sheet-like pattern characterized by large, round, pleomorphic or vesicular nuclei, prominent nucleoli, and frequent mitotic activities. Classical acinic architectures focally merged together to form solid nests and transited into high-grade areas. Remarkably, in the high-grade lesion, conventional immunochemical markers for breast AciCC, such as α1-antitrypsin (AAT), Lysozyme (LYS), Epithelial membrane antigen (EMA), S100 protein (S100), and cytokeratin (CK) were negative, whereas cell cycle protein D1 (cyclin D1) and vimentin showed diffuse expression. Next‑generation sequencing (NGS) revealed that 43.5% of variants were identical in both components. Furthermore, PAK5 mutation; copy number (CN) loss of CDH1, CHEK1, and MLH1; and CN gains of CDK6, HGF, and FOXP1 were identified in the high-grade lesion. The patient was treated with eight cycles of adjuvant chemotherapy (epirubicin combined with cyclophosphamide) and radiotherapy after surgery, and she is currently alive for 43 months with no metastases or recurrences.ConclusionsThis case demonstrates a comparative analysis of the histopathological and genetic characteristics of classical low-grade and high-grade components of AciCC within the same breast. This information may serve as a morphological and molecular basis for further investigation into the molecular mechanisms underlying high-grade lesions in breast AciCC.

Computational microfluidics of reactive transport processes with solid dissolution and self-induced multiphase flow

There are still many unclear mechanisms in the multiphase reactive flow with solid dissolution processes. In this study, the reactive transport processes coupled with solid dissolution and self-induced multiphase flow in three-dimensional (3D) structures with increasing complexity is studied by developing a 3D computational microfluidic method, which considers multiphase flow, interfacial mass transport, heterogeneous chemical reactions, and solid structure evolution. Solid dissolution diagram in a simple channel in the framework of multiphase flow is proposed, with six coupled multiphase flow and solid dissolution patterns identified and the transition between different patterns discussed. Then, multiphase reactive flow in a porous chip is further studied, and the interesting 3D phenomena are discovered, including enhanced solid dissolution in the middle and enriched bubble generation at the corner along the thickness direction. Considering the importance of reactive surface area, correlations of reactive surface area-porosity-saturation with different dissolution patterns are proposed based on the pore-scale results. Finally, the computational microfluidic model is extended to investigate the multiphase reactive flow in a 3D digital core. Different dissolution patterns are recognized using the local porosity evolution character, and the corresponding pore size distribution and bubble characteristics are deciphered. These findings advance understanding of multiphase reactive transport processes and contribute to improve continuum-scale reactive transport modeling.

Pathologic characterization of precursors and cholangiocarcinoma referring to peribiliary capillary plexus: a new pathologic approach to bile duct neoplasm.

The peribiliary capillary plexus (PCP) regularly and densely lines the basal side of the lining epithelia of normal bile ducts. To determine the pathology of the PCP in high-grade biliary intraepithelial neoplasms (BilINs) and intraductal papillary neoplasms of the bile duct (IPNBs), a precursor of cholangiocarcinoma (CCA), and CCA. Seventy-six cases of surgically resected high-grade BilIN and 83 cases of IPNB were histopathologically examined using endothelial immunostaining of PCP; all cases of high-grade BilIN and 40 cases of IPNB were associated with invasive CCA. Invasive and preinvasive neoplasms were pathologically examined referring to a two-layer pattern composed of biliary lining epithelia and underlying PCP unique to the bile duct. All high-grade BilIIN cases had an underlying single layer of capillaries, similar to PCP (PCP-like capillaries). In 43% of the 83 cases of IPNB, these capillaries were regularly distributed in almost all stalks and intervening stroma of intraluminal neoplastic components, while in the remaining 57% of IPNB, capillaries were sparsely or irregularly distributed in intraluminal components showing cribriform or solid growth patterns composed of striking atypical neoplastic epithelia. Invasive carcinomas associated with high-grade BilIN and IPNB were not lined with capillaries. The loss of PCP-like capillaries underlying high-grade BilIN and in stalks or stroma of IPNB may be involved in the malignant progression of these precursors. Immunostaining of PCP could be a new pathological tool for the evaluation of malignant progression and vascular supply in CCA and its precursors.

Clinical, Radiologic, and Surgical Features of Brain Metastases in Colorectal Cancer. A Strong Correlation Between Surgical Patterns and Outcome

Brain metastases (BMs) from colorectal cancer (CRC) are a small percentage of metastatic patients and surgery is considered the best choice to improve survival. While most research has focused on the risk of CRC spreading to the brain, no studies have examined the characteristics of BMs in relation to surgery and outcome. In this study, we evaluate the clinical and radiologic features of BMs from CRC patients who underwent surgery and analyze their outcomes. The study is a retrospective observational analysis that included a cohort of 31 patients affected by CRC surgically-treated for their related BMs. For all patients, clinical and surgical data (number, site, side, tumor and edema volume, and morphology) were recorded. Analysis found that synchronous diagnosis and lesion morphology, particularly cystic versus solid, had the most significant impact on survival (6 vs. 22months, P= 0.04). To compare BMs with cystic morphology to those with solid morphology, a multivariate analysis was conducted. No significant differences were observed between the 2 groups in terms of age, sex, clinical onset, or performance status. The analysis revealed no significant differences in localization with regard to site, tumor and edema volume, biology, or complications rate. BMs derived from CRC have a significantly different prognosis depending on whether they present as a solid or cystic pattern. Although solid pattern is more common, cystic BMs in this tumor type are less frequent and are associated with a poorer prognosis, regardless of molecular expression, location, size, and adjuvant treatment.

Machine Learning Classification of Local Environments in Molecular Crystals.

Identifying local structural motifs and packing patterns of molecular solids is a challenging task for both simulation and experiment. We demonstrate two novel approaches to characterize local environments in different polymorphs of molecular crystals using learning models that employ either flexibly learned or handcrafted molecular representations. In the first case, we follow our earlier work on graph learning in molecular crystals, deploying an atomistic graph convolutional network combined with molecule-wise aggregation to enable per-molecule environmental classification. For the second model, we develop a new set of descriptors based on symmetry functions combined with a point-vector representation of the molecules, encoding information about the positions and relative orientations of the molecule. We demonstrate very high classification accuracy for both approaches on urea and nicotinamide crystal polymorphs and practical applications to the analysis of dynamical trajectory data for nanocrystals and solid-solid interfaces. Both architectures are applicable to a wide range of molecules and diverse topologies, providing an essential step in the exploration of complex condensed matter phenomena.

Clear cell adenocarcinoma of the cervix and its mimickers - A series of 19 cases from a tertiary care referral centre in India.

Clear cell adenocarcinoma (CCAC) of cervix is a rare subtype of endocervical adenocarcinoma that accounts for 4% of all cervical adenocarcinoma with many morphological mimickers. Retrospectively study cases of cervical clear cell adenocarcinoma of the cervix. Clinical profile and pathological features of CCAC of the cervix diagnosed between 2018-2022 were retrospectively analyzed.The database of the Department of Pathology of our institute was systematically searched for patients diagnosed with clear cell adenocarcinoma of the cervix during 2018-2022.A total of 19 patients were studied with the mean age of patients being 53.72 years (range 25 -84 yrs,standard deviation-25.9) and median tumor size being 5.6cm. Lymph node metastasis was identified in 33.3% and distant metastasis were seen in 20% of the cases. Staging could not be done in 4 cases.FIGO staging of the cases included IB1(2 cases), IB2(2 cases), IIB (3 cases),IIIA (1 case)IIIB(4 cases),and IV(3 cases). On histopathological evaluation, heterogeneous architectural pattern comprising of tubulocystic, solid, and papillary patterns were seen in 13 cases (13/19,68.4%). Pure tubulocystic (3/19,15.7%), pure papillary (2/19,10.5%), and pure solid patterns (1/19,5.3%) were also identified. Tumor cells with clear cytoplasm ranged from 5% to 95%. Nuclear atypia was moderate to marked in all the cases (19/19,100%). Mitotic activity varied from 1/10hpf to 20-22/10hpf. By immunohistochemistry, tumor was positive for Napsin A in all the cases,p16INK4a was negative in majority of cases (15/19,78.9%) and ER was negative in 14 cases (14/19,73.7%) .p53 showed wild type staining except for one case . Clear cell adenocarcinoma being a rare subtype of cervical adenocarcinoma, needs to be differentiated from other Human Papilloma Virus(HPV) independent adenocarcinomas (gastric and mesonephric types) and benign entities such as endocervical glandular Arias-Stella reaction. Judicious use of a panel of immunostains is often helpful.

Non-small cell lung carcinoma with clear cell features: a clinicopathologic, immunohistochemical, and molecular study of 31 cases.

Non-small cell lung carcinoma with predominantly clear cell features is a rare histologic presentation of lung carcinoma. We have examined 31 cases of lung carcinomas showing extensive clear cell features. The patients were 10 women and 21 men aged 47-92years (mean: 70years). The tumors showed a predilection for the right upper and lower lobes and measured from 0.8 to 9.5cm (mean: 4.2cm). By immunohistochemistry, 9 cases were typed as adenocarcinoma, 19 cases as squamous cell carcinoma, and 3 showed a "null" phenotype with complete loss of markers for adenocarcinoma or squamous cell carcinoma. Most cases that typed as adenocarcinoma showed a solid growth pattern. A subset of the solid adenocarcinoma cases showed a distinctive "pseudosquamous" morphology. Next-generation sequencing was performed in 20 cases and showed a variety of molecular alterations. The most common abnormalities were found in the TP53 gene (9 cases), FGFR gene family (8 cases), KRAS (5 cases), AKT1 (5 cases), and BRAF (3 cases). Clinical follow-up was available in 21 patients; 16/21 patients died of their tumors from 6months to 12years after initial diagnosis (mean: 4.2years, median: 1.5years). Four patients were alive and well from 4 to 27years (mean: 11.5years, median: 7.5years); all were pathologic stage 1 or 2. NSCLC with clear cell features can display aggressive behavior and needs to be distinguished from various other tumors of the lung that can show clear cell morphology. The identification of targetable molecular alterations in some of these tumors may be of value for therapeutic management.

Chemical heterogeneity size effects at nanoscale on interface thermal resistance of solid–liquid polymer interface via molecular dynamics simulations

The shrinking size of integrated chips poses thermal management challenges. Understanding the size effect of chemical heterogeneity on solid–liquid interfacial thermal transfer is essential for heterogeneous chip design, yet the underlying mechanisms remain lacking. The present work used the liquid n-alkanes as the thermal interface material between solid platinum substrates. To characterize chemical heterogeneity, periodic solid surface patterns composed of patches with alternating solid–liquid affinities were constructed. By using non-equilibrium molecular dynamics simulations, we investigated the size effect of chemically heterogeneous patterns on interfacial thermal resistance (ITR) at the nanoscale. At larger heterogeneity sizes, i.e., larger patch sizes, most alkane molecules directly in contact weak interaction patches cannot interact with strong interaction patches due to long atomic distances. In the case of alkanes in contact a cold substrate, alkanes in contact weak interaction patches transferred thermal energy to the substrate at a lower rate than those in contact strong interaction patches. The different rates resulted in the higher temperature of alkanes in contact weak interaction patches than those in contact strong interaction patches and, therefore, a larger disparity between temperature jump at the strong interaction areas and that at the weak interaction areas. The non-uniformity of temperature jump distribution increased ITR when compared to the heterogeneous surface system characterized by a smaller patch size with a more uniform temperature distribution in the plane perpendicular to the heat flux direction. In addition, the classical parallel thermal resistance model predicted ITR accurately for the heterogeneous surface systems with small size patches but overestimated overall thermal resistance.

Reassessment of EUS features in preoperative diagnosis of pancreatic serous cystic neoplasm: Lessons to avoid misdiagnosis.

Pancreatic serous cystic neoplasm (SCN) is a benign cystic neoplasm that is likely to be surgically resected due to preoperative misdiagnosis or tentative diagnosis even using endoscopic ultrasonography (EUS). We aimed to analyze EUS findings of SCN associated with misdiagnosis. Between January 2012 and September 2023, histologically confirmed pancreatic SCN were included and EUS features were reviewed. Overall, 294 patients with 300 surgically resected SCNs were included. The median age of the patients was 51 years and 75.9% were females. The lesions were predominantly located in the body/neck/tail of the pancreas (63.0%). The overall preoperative diagnostic rate of SCN was 36.3%, with the most common misdiagnosis being intraductal papillary mucinous neoplasm (IPMN) (31.3%), while 16.3% remained undefined. The preoperative diagnostic rate of SCN varied across different endosonographic morphologies, with oligocystic, macrocystic, microcystic, and solid patterns yielding rates of 12.8%, 37.9%, 76.5%, and 19.2%, respectively. Notably, the presence of central scar and vascularity improved the diagnostic accuracy and correctly identified 41.4% and 52.3% of thelesions. While mucus or pancreatic duct (PD) communication significantly increased the likelihood of misdiagnosis, particularly as IPMN. Multivariate analysis revealed a morphological pattern, mucin-producing signs, wall thickening, vascularity, and PD communication were independent factors related to preoperative misdiagnosis, with an overall accuracy of 82.3%. Preoperative diagnosis of SCN remains challenging. The microcystic pattern emerged as a reliable feature, while mucin-producing signs, including mural nodules, mucus, and PD communication, pose diagnostic pitfalls despite the presence of typical central scar or vascularity commonly in SCN.

AN ENGINEERED SYSTEM FOR SOLID WASTE COLLECTION IN SAMARU, ZARIA, NIGERIA

Solid waste includes all materials that are firm and stable in shape including semisolid materials that are no longer considered of sufficient value to be retained in a given setting. Solid waste generation rates and patterns within the study area were mapped out through GPS, Google route software, AutoCAD, ArcGIS, GPS, Route optimization software, measuring tape, Marker, Containers of equal volume, Record book, Calculator, and Stopwatch. Eleven sacks were used to collect solid waste from eleven different households daily within three months of the wet and dry seasons of the year. The highest average volume of solid waste generated per household per week in Samaru was in the dry season =0.25 m3. The dry season witnesses a substantial volume of 0.206 m³ for garbage organic materials, constituting 66.45% of the total composition. In the wet season, this volume remains significant at 0.104 m³, accounting for 61.18% of the total composition. The highest percentage of organic materials (garbage) during both seasons suggests a need for improved organic waste management. The minimum allowable capacity of the solid waste collection containers for the designed system is 10 m3 considering a minimum of two containers per city block

Association between non-alcoholic fatty liver disease and the risk of pulmonary nodules in patients with intestinal polyps.

Associations between metabolic risk factors and lung cancer remain elusive, and evidence on the linkage between non-alcoholic fatty liver disease (NAFLD) and pulmonary nodules is limited. This study sought to examine the independent association between NAFLD and the risk of pulmonary nodules. Cross-sectional analyses of 1,119 patients with intestinal polyps hospitalized at the Department of Gastroenterology, Minhang District Central Hospital of Shanghai, China, were conducted. NAFLD was diagnosed based on hepatic ultrasonography or computed tomography (CT) findings of hepatic steatosis, with exclusion criteria ensuring patients had no history of significant alcohol consumption, viral infections, or hepatic autoimmune diseases. The currently accepted definition of a pulmonary nodule is a solid or sub-solid shadow ≤3 cm in diameter that appears as a solid or semi-solid pattern on a chest CT scan (our specific treatment is pulmonary nodule size: 5 mm to 3 cm). Adjusted 95% confidence intervals (CIs) and odds ratios (ORs) for NAFLD and the clinical features connected with pulmonary nodule risk were determined using a multivariable logistic regression analysis. Among the 979 intestinal polyp patients, the prevalence rates of NAFLD and pulmonary nodules were 25.9% and 32.8%, respectively. Patients with pulmonary nodules exhibited higher rates of NAFLD (31.5% vs. 23.3%, P=0.006) and obesity (41.4% vs. 32.5%, P=0.006) compared to those without pulmonary nodules. After removing all the possible confounding variables, the adjusted ORs for NAFLD, an older age, smoking, and obesity were 1.370 (95% CI: 1.006-1.867, P=0.04), 1.022 (95% CI: 1.010-1.033), 1.599 (95% CI: 1.033-2.475), and 1.410 (95% CI: 1.057-1.880), respectively (all P values <0.05). NAFLD showed a significant association with an increased risk of pulmonary nodules. NAFLD was independently linked to an increased incidence of pulmonary nodules in intestinal polyp patients, which emphasizes the importance of screening and managing these conditions in lung cancer prevention.

Development and validation of a clinical decision tool for preoperative micropapillary and solid pattern lung adenocarcinoma of CT≤2cm.

Micropapillary (MP) and solid(S) pattern adenocarcinoma are highly malignant subtypes of lung adenocarcinoma. In today's era of increasingly conservative surgery for small lung cancer, effective preoperative identification of these subtypes is greatly important for surgical planning and long term survival of patients. For this retrospective study, the presence of MP and/or S was evaluated in 2167 consecutive patients who underwent surgical resection for clinical stage IA1-2 lung adenocarcinoma. MP and/or S pattern-positive patients and negative-pattern patients were matched at a ratio of 1:3. The Lasso regression model was used for data dimension reduction and imaging signature building. Multivariate logistic regression was used to establish the predictive model, presented as an imaging nomogram. The performance of the nomogram was assessed based on calibration, identification, and clinical usefulness, and internal and external validation of the model was conducted. The proportion of solid components (PSC), Sphericity, entropy, Shape, bronchial honeycomb, nodule shape, sex, and smoking were independent factors in the prediction model of MP and/or S lung adenocarcinoma. The model showed good discrimination with an area under the ROC curve of 0.85. DCA demonstrated that the model could achieve good benefits for patients. RCS analysis suggested a significant increase in the proportion of MP and/or S from 11% to 48% when the PSC value was 68%. Small MP and/or S adenocarcinoma can be effectively identified preoperatively by their typical 3D and 2D imaging features.

Small cell neuroendocrine carcinoma and poorly differentiated rhabdomyosarcomas of the urinary bladder in adults—A comparative analysis in favor of a common histogenesis

Rhabdomyosarcoma (RMS) of the urinary bladder in adults and elderly is an exceptionally rare neoplasm that displays poorly differentiated solid (alveolar-like) small cell pattern, frequently indistinguishable from small cell neuroendocrine carcinoma (SCNEC). However, the histogenesis of RMS and SCNEC and their inter-relationship have not been well studied and remained controversial. We herein analyzed 23 SCNEC and 3 small round cell RMS of the bladder for neuroendocrine (synaptophysin + chromogranin A) and myogenic (desmin + myogenin) marker expression and for TERT promoter mutations. In addition, the RMS cohort and one SCNEC that was revised to RMS were tested for gene fusions using targeted RNA sequencing (TruSight Illumina Panel which includes FOXO1 and most of RMS-related other genes). Overall, significant expression of myogenin and desmin was observed in one of 23 original SCNEC justifying a revised diagnosis to RMS. On the other hand, diffuse expression of synaptophysin was noted in 2 of the 4 RMS, but chromogranin A was not expressed in 3 RMS tested. TERT promoter mutations were detected in 15 of 22 (68%) SCNEC and in two of three (67%) assessable RMS cases, respectively. None of the four RMS cases had gene fusions. Our data highlights phenotypic and genetic overlap between SCNEC and RMS of the urinary bladder. High frequency of TERT promoter mutations in SCNEC is in line with their presumable urothelial origin. In addition, the presence of TERT promoter mutation in 2 of 3 RMS and lack of FOXO1 and other gene fusions in all 4 RMSs suggest a mucosal (urothelial) origin, probably representing extensive monomorphic rhabdomyoblastic transdifferentiation in SCNEC.

Efficacy of cytotoxic chemotherapy in recurrent/metastatic adenoid cystic carcinoma (ACC).

6111 Background: Despite aggressive local therapy, many ACC patients (~50%) develop recurrent and/or metastatic (R/M) disease. However, there is no standard of care or FDA-approved systemic therapy for this population. Based on small phase II trials, mostly including multiple salivary gland histologies, cytotoxic chemotherapy is recommended for symptomatic patients with high tumor burden, but its efficacy and impact on survival in R/M ACC remain unsubstantiated. Methods: A retrospective cohort study was conducted at MD Anderson Cancer Center with an institutional ACC database (N=769). Patients diagnosed with R/M ACC and treated with single-agent or combination palliative-intent chemotherapy were included. The primary endpoints were overall response rate (ORR) and disease control rate (DCR) per RECIST 1.1. Secondary endpoints were median overall survival (mOS) and progression-free survival (mPFS) on chemotherapy for the entire cohort and stratified by growth pattern (solid v non-solid), line of therapy (1 v &gt;2), chemotherapy regimen, and stage at diagnosis (M0 v M1). Results: 48 out of 115 patients who received chemotherapy were evaluated for response per RECIST.Median age at diagnosis was 43.6 years. 56% were male, 79% had M0 stage at diagnosis, 67% had minor salivary gland primary tumors, 52% had solid growth pattern, 31% had non-solid growth pattern, and 54% received first-line chemotherapy. The most common regimens were Platinum/Vinorelbine (38%), Platinum/Taxane (27%) and CAP (15%).The ORR and DCR rates were 12.5% and 56.3% respectively; 6 had partial response, 21 had stable disease, and 21 had progressive disease. The ORR and DCR rates were 20% and 52% for solid and 6.7% and 73.3% for non-solid growth pattern, respectively. The mOS from diagnosis was 7 years (95% CI, 3.5-10.7). The mOS on chemotherapy was 16 months (95% CI, 10.8-24.5). There was a significant difference in mOS between solid and non-solid growth pattern (10.8 v 24.1 months, p=0.015), but not by line of therapy, regimen, or stage at diagnosis. The mPFS on chemotherapy was 4.3 months (95% CI, 2.8-6.3 months). There was a significant difference in mPFS between solid and non-solid growth pattern (4.0 v 7.3 months, p=0.018), but not by line of therapy, regimen, or stage at diagnosis. Conclusions: In this largest to date real-world data on chemotherapy in ACC, response and survival outcomes were lower than historical data. The efficacy of chemotherapy may vary by growth pattern and other patient and tumor factors, which requires further investigation. Given the low ORR and overall slow-growing disease pattern, tumor volumetrics may be better than RECIST to assess treatment benefit.

Acquired cystic disease associated renal cell carcinoma: A clinicopathologic and molecular study of 31 tumors

Acquired cystic disease associated renal cell carcinomas (ACD-RCC) are rare and their molecular and histopathological characteristics are still being explored. We therefore investigated the clinicopathologic and molecular characteristics of 31 tumors. The patients were predominantly male (n = 30), with tumors mainly left-sided (n = 17), unifocal (n = 19), and unilateral (n = 29) and a mean tumor size of 25 mm (range, 3–65 mm). Microscopically, several histologic patterns were present, including pure classic sieve-like (n = 4), and varied proportions of mixed classic sieve-like with papillary (n = 23), tubulocystic (n = 9), compact tubular (n = 4) and solid (n = 1) patterns. Calcium-oxalate crystals were seen in all tumors. Molecular analysis of 9 tumors using next generation sequencing showed alterations in SMARCB1 in 3 tumors (1 with frameshift deletion and 2 with copy number loss in chromosome 22 involving SMARCB1 region), however, INI1 stain was retained in all. Nonrecurrent genetic alterations in SETD2, NF1, NOTCH4, BRCA2 and CANT1 genes were also seen. Additionally, MTOR p.Pro351Ser was identified in one tumor. Copy number analysis showed gains in chromosome 16 (n = 5), 17 (n = 2) and 8 (n = 2) as well as loss in chromosome 22 (n = 2). In summary, ACD-RCC is a recognized subtype of kidney tumors, with several histological architectural patterns. Our molecular data identifies genetic alterations in chromatin modifying genes (SMARCB1 and SETD2), which may suggest a role of such genes in ACD-RCC development.

Clinical outcomes in salivary adenoid cystic carcinoma.

6102 Background: Adenoid cystic carcinoma (ACC) is a rare salivary gland malignancy with a paucity of clinical outcome data. As such, evidence supporting and informing current guidelines remains limited. Methods: Inclusion criteria stipulated adults with adenoid cystic carcinoma treated at the University of Michigan between 1988 and 2019 with complete records (n=102). Clinical variables including demographics, disease stage, and treatment modality were abstracted. Pathologic variables analyzed included tumor grade, perineural invasion, lymphovascular invasion, and surgical margin status. Multivariate analyses were performed with disease recurrence calculated with Kaplan-Meier methodology as the primary outcome. Results: Mean age at diagnosis was 59 years; stage I and II disease accounted for 35 (38%) patients. Initial treatment was most commonly surgery with adjuvant radiation (77%). Median follow-up was 3 years. Distant metastatic disease developed in 34 (33%) patients. Most common sites included lung (68%), bone (21%), and brain (21%). Median time to distant metastases was 46 months with median overall survival of 58 months. Patients with locoregional recurrence experienced median survival of 91 months. Multivariate analysis adjusted for grade, perineural invasion, and surgical margin status (Table). Grade 3 tumors with predominantly solid histologic pattern pose higher risk of recurrence compared to grade 1 tubular histologic patterns as a reference (HR 3.69, 95% CI 1.15-11.88, p=0.028). Conclusions: Survival among patients with adenoid cystic carcinoma after locoregional recurrence is significantly better compared to those experiencing distant metastasis. Furthermore, tumor grade is most predictive of recurrence. Additionally, distant metastases may emerge over the course of many years. These data from one of the largest retrospective databases to date may inform the development of disease-specific surveillance guidelines and novel salvage treatment paradigms. [Table: see text]

The histopathological spectrum and molecular changes associated with KRAS G12C mutation in non-small cell lung carcinoma

KRAS G12C is the most common KRAS mutation in non-small cell lung carcinoma (NSCLC), for which targeted therapy has recently been developed. From the 732 cases of NSCLC that underwent next-generation sequencing at the Department of Anatomical Pathology, Liverpool Hospital, between July 2021 and May 2023, we retrieved 83 (11%) consecutive cases of KRAS G12C mutated NSCLC, and analysed their clinical, pathological, and molecular features. Of the 83 cases of KRAS G12C mutated NSCLC, there were 46 (55%) men and 37 (45%) women, with mean age of 72 years. Of the 49 cases with known clinical information, 94% were current or ex-smokers, and 49% were stage IV at diagnosis with median survival of 12 months. Sixty-three percent were histology cases and the remainder were cytology cases. Eighty-two percent were non-mucinous adenocarcinomas, with conventional histology including lepidic, acinar, solid, single cells and micropapillary patterns, and 62% were poorly differentiated. There were five (6%) cases of mucinous adenocarcinoma, one case of pleomorphic carcinoma and one case of high-grade fetal adenocarcinoma. TTF1 was positive in the majority (89%) of cases. Nineteen (23%) cases had TP53 co-mutation, and these cases had trends towards higher PD-L1 expression, poor differentiation, and presentation as stage IV disease, but the differences were not statistically significant. KRAS G12C mutated NSCLCs almost exclusively occurred in smokers and were mostly non-mucinous adenocarcinomas with conventional histological patterns which ranged from well to poorly differentiated. Around a quarter had TP53 co-mutation, the histological impacts and immune profile of which need to be assessed in a larger study.

Porocarcinomas with PAK1/2/3 fusions: a series of 12 cases.

Porocarcinoma is a malignant sweat gland tumour differentiated toward the upper part of the sweat duct and may arise from the transformation of a preexisting benign poroma. In 2019, Sekine etal. demonstrated the presence of YAP1::MAML2 and YAP1::NUTM1 fusions in most poromas and porocarcinomas. Recently, our group identified PAK2-fusions in a subset of benign poromas. Herein we report a series of 12 porocarcinoma cases harbouring PAK1/2/3 fusions. Five patients were male and the median age was 79 years (ranges: 59-95). Tumours were located on the trunk (n = 7), on the thigh (n = 3), neck (n = 1), or groin area (n = 1). Four patients developed distant metastases. Microscopically, seven cases harboured a benign poroma component and a malignant invasive part. Ductal formations were observed in all, while infundibular/horn cysts and cells with vacuolated cytoplasm were detected in seven and six tumours, respectively. In three cases, the invasive component consisted of a proliferation of elongated cells, some of which formed pseudovascular spaces, whereas the others harboured a predominant solid or trabecular growth pattern. Immunohistochemical staining for CEA and EMA confirmed the presence of ducts. Focal androgen receptor expression was detected in three specimens. Whole RNA sequencing evidenced LAMTOR1::PAK1 (n = 2), ZDHHC5::PAK1 (n = 2), DLG1::PAK2, CTDSP1::PAK1, CTNND1::PAK1, SSR1::PAK3, CTNNA1::PAK2, RNF13::PAK2, ROBO1::PAK2, and CD47::PAK2. Activating mutation of HRAS (G13V, n = 3, G13R, n = 1, Q61L, n = 2) was present in six cases. Our study suggests that PAK1/2/3 fusions is the oncogenic driver of a subset of porocarcinomas lacking YAP1 rearrangement.

Pseudosquamous Adenocarcinoma of the Lung: Clinicopathologic and Immunohistochemical Study of 10 Cases.

Pseudosquamous adenocarcinoma of the lung is an unusual morphologic variant of poorly differentiated non-small cell lung carcinoma that superficially resembles a squamous cell carcinoma. We have examined 10 cases of these tumors in 4 women and 6 men, aged 47 to 93 years. The tumors were all peripheral and measured from 1.5 to 5.5cm. All cases were characterized by solid nests of large polygonal tumor cells containing atypical nuclei with abundant cytoplasm and sharp cell borders, adopting a pavement-like architecture that simulated squamous cell carcinoma. Some cases demonstrated intracytoplasmic hyaline inclusions suggestive of keratinization. The nests of tumor cells often showed central comedo-like areas of necrosis. Intercellular bridges were not seen in any of the cases. The tumors often displayed marked clearing of the cytoplasm enhancing their epidermoid appearance. In 4 cases, the solid pseudosquamous areas were seen to merge with a focal lepidic adenocarcinoma component, and in 1 case, abortive microscopic foci of acinar differentiation were also noted within the tumor. One case showed focal sarcomatoid spindle cell areas. The tumor cells were negative for p40 and CK5/6 and labeled with TTF1 or Napsin-A, confirming an adenocarcinoma phenotype. Clinical follow-up information was available in 8 patients; 6 patients died of their tumors between 6 months to 11 years after diagnosis (mean: 3.1y). One patient died of complications related to surgery and one patient with a low-stage tumor died at 27 years from other causes. Solid pattern adenocarcinomas can be confused for squamous cell carcinoma and may require immunohistochemistry to determine their true phenotype.