A challenging case of an adamantinoma of fibula with soft tissue mass harboring distinct histopathology.

We present a case of adamantinoma that originated from the fibula and had a large soft tissue component measuring approximately 6 cm. Clinical, radiological, and pathological investigations initially suggested that the tumor might be a bone-invading synovial sarcoma. To the best of our knowledge, no other case of fibular adamantinoma with such a large soft tissue component has been reported in the literature.

Calcifying Spindle Cell Soft Tissue Tumor With SOX10::PLAG1 Fusion: A Case Report of a Morphologically Distinctive and Potentially Novel Soft Tissue Tumor.

The widespread use of advanced molecular techniques has led to the identification of several tumor types with PLAG1 gene fusions some of which also affect the skin and soft tissues. Herein, we present a 38-year-old female with a subcutaneous tumor affecting her forearm, which does not seem to fit into any currently recognized entity. It was a well-circumscribed tumor measuring 6 × 4,5 × 4 cm. It had a thick capsule composed of bland spindle cells forming palisades and Verocay body-like structures within a myxocollagenous background. Scattered calcifications were dispersed throughout the lesion. No cytological atypia, mitotic activity, or necrosis were present. Targeted NGS revealed a SOX10::PLAG1 fusion and fluorescent in situ hybridization confirmed the presence of PLAG1 gene rearrangement. The neoplastic cells showed a diffuse immunohistochemical expression of S100, SOX10, and PLAG1, as well as patchy desmin and CD34 positivity. The methylation profile of this tumor did not match any other entity covered by the DKFZ sarcoma classifier and apart from the gain of chromosome 12, the copy number profile was normal. The tumor was completely excised, and the patient has been free of disease for 4 years since the excision. While more cases are needed to confirm this tumor as a distinct entity, we propose a provisional name "SOX10::PLAG1-rearranged calcifying spindle cell tumor."

A Comprehensive Clinicopathologic and Molecular Reappraisal of GLI1-altered Mesenchymal Tumors with Pooled Outcome Analysis Showing Poor Survival in GLI1- amplified Versus GLI1-rearranged Tumors.

GLI1-altered mesenchymal tumor is a recently described distinct pathologic entity with an established risk of malignancy, being defined molecularly by either GLI1 gene fusions or amplifications. The clinicopathologic overlap of tumors driven by the 2 seemingly distinct mechanisms of GLI1 activation is still emerging. Herein, we report the largest series of molecularly confirmed GLI1-altered mesenchymal neoplasms to date, including 23 GLI1-amplified and 15 GLI1-rearranged new cases, and perform a comparative clinicopathologic, genomic, and survival investigation. GLI1-rearranged tumors occurred in younger patients (42 vs. 52 y) and were larger compared with GLI1-amplified tumors (5.6 cm vs. 1.5 cm, respectively). Histologic features were overall similar between the 2 groups, showing a multinodular pattern and a nested architecture of epithelioid, and less commonly spindle cells, surrounded by a rich capillary network. A distinct whorling pattern was noted among 3 GLI1-amplified tumors. Scattered pleomorphic giant cells were rarely seen in both groups. The immunoprofile showed consistent expression of CD56, with variable S100, CD10 and SMA expression. Genomically, both groups had overall low mutation burdens, with rare TP53 mutations seen only in GLI1-amplified tumors. GLI1-amplified mesenchymal tumors exhibit mostly a single amplicon at the 12q13-15 locus, compared with dedifferentiated liposarcoma, which showed a 2-peak amplification centered around CDK4 (12q14.1) and MDM2 (12q15). GLI1-amplified tumors had a significantly higher GLI1 mRNA expression compared with GLI1-rearranged tumors. Survival pooled analysis of current and published cases (n=83) showed a worse overall survival in GLI1-amplified patients, with 16% succumbing to disease compared with 1.7% in the GLI1-rearranged group. Despite comparable progression rates, GLI1-amplified tumors had a shorter median progression-free survival compared with GLI1-rearranged tumors (25 mo vs. 77 mo). Univariate analysis showed that traditional histologic predictors of malignancy (mitotic count ≥4/10 high-power fields, presence of necrosis, and tumor size ≥5 cm) are associated with worse prognosis among GLI1-altered mesenchymal tumors.

Differential cyclin-E1 expression in CIC-rearranged sarcoma.

CIC-rearranged sarcoma (CRS) is a group of high-grade undifferentiated small round cell sarcomas examined as a separate entity in the current WHO classification; since it shows more aggressive clinical behavior and distinct morphological and molecular features compared to Ewing sarcoma (ES). As CCNE1 expression is associated with tumor growth in CIC::DUX4 sarcomas, we aimed to demonstrate the value of cyclin E1 expression in CRS. Cyclin E1 immunohistochemistry and break-apart FISH for EWSR1 and CIC gene rearrangements were performed on 3-mm tissue microarrays composed of 40 small round cell tumors. Five cases were classified as CRS, whereas 22 were ES and 13 were unclassified (EWSR1-/CIC-). Among all three diagnostic groups, we found cyclin E1 expression level to be higher in CRS (80 %) and unclassified groups (61.5 %) compared to ES (4.5 %, p < 0.001). In addition, high cyclin E1 expression levels were associated with higher mean age at diagnosis, presence of atypical histology and myxoid stroma, low CD99 expression, and presence of metastasis at diagnosis. The sensitivity and specificity of high cyclin E1 expression in detecting non-ES cases were 95.5 % and 66.7 %, respectively. However, the correlation between cyclin E1 expression level and survival was not statistically significant. This is the first study that shows cyclin E1 immunohistochemical expression in EWSR1-negative undifferentiated small cell sarcomas, particularly CRS.

Hyaline fibromatosis syndrome: a rare, yet recognizable syndrome.

BACKGROUND: Hyaline fibromatosis syndrome is a rare autosomal recessive disorder caused by ANTXR2 pathogenic variants. The disorder is characterized by the deposition of amorphous hyaline material in connective tissues. The hallmarks of the disease are joint contractures, generalized skin stiffness, hyperpigmented papules over extensor surfaces of joints, fleshy perianal masses, severe diarrhea, and gingival hypertrophy. The severity of the disease varies and prognosis is poor. No specific treatment is yet available. Most patients with the severe form of the condition pass away before the second year of age. In this study, we describe the clinical and molecular findings of a cohort of seven hyaline fibromatosis syndrome patients who were diagnosed and followed up at a single tertiary reference center in Turkey. METHODS: Genomic DNA was extracted by standard salting out method from peripheric blood samples of three patients. In one patient DNA extraction was performed on pathology slides since peripheric blood DNA was not available. All coding exons of the ANTXR2 were amplified and sequenced on ABI Prism 3500 Genetic Analyser. RESULTS: Sanger sequencing was performed in 3 patients and homozygous c.945T>G p.(Cys315Trp), c.1073dup p.(Ala359CysfsTer13), and c.1074del p.(Ala359HisfsTer50) variants were identified in ANTXR2. All patients passed away before the age of five years. CONCLUSIONS: HFS is a rare, progressive disorder with a broad phenotypic spectrum. HFS can be recognized easily with distinctive clinical features. Nevertheless, it has poor prognosis with increased mortality due to severe clinical decompensation.

Comprehensive clinicopathological, molecular, and methylation analysis of mesenchymal tumors with NTRK and other kinase gene aberrations.

Alterations in kinase genes such as NTRK1/2/3, RET, and BRAF underlie infantile fibrosarcoma (IFS), the emerging entity 'NTRK-rearranged spindle cell neoplasms' included in the latest WHO classification, and a growing set of tumors with overlapping clinical and pathological features. In this study, we conducted a comprehensive clinicopathological and molecular analysis of 22 cases of IFS and other kinase gene-altered spindle cell neoplasms affecting both pediatric and adult patients. Follow-up periods for 16 patients ranged in length from 10 to 130 months (mean 38 months). Six patients were treated with targeted therapy, achieving a partial or complete response in five cases. Overall, three cases recurred and one metastasized. Eight patients were free of disease, five were alive with disease, and two patients died. All cases showed previously reported morphological patterns. Based on the cellularity and level of atypia, cases were divided into three morphological grade groups. S100 protein and CD34 were at least focally positive in 12/22 and 14/22 cases, respectively. Novel PWWP2A::RET, NUMA1::RET, ITSN1::RAF1, and CAPZA2::MET fusions, which we report herein in mesenchymal tumors for the first time, were detected by RNA sequencing. Additionally, the first uterine case with BRAF and EGFR mutations and CD34 and S100 co-expression is described. DNA sequencing performed in 13 cases uncovered very rare additional genetic aberrations. The CNV profiles showed that high-grade tumors demonstrate a significantly higher percentage of copy number gains and losses across the genome compared with low- and intermediate-grade tumors. Unsupervised clustering of the tumors' methylation profiles revealed that in 8/9 cases, the methylation profiles clustered with the IFS methylation class, irrespective of their clinicopathological or molecular features. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Myeloid sarcoma with RBM15::MRTFA (MKL1) mimicking vascular neoplasm.

Extramedullary involvement of acute myeloid leukemia (AML), aka myeloid sarcoma, is a rare phenomenon in acute megakaryoblastic leukemia with RBM15:: MRTFA(MKL1) fusion, which might mimic non-hematologic malignancies. A 7-month-old infant presented with leukocytosis, hepatosplenomegaly, multiple lymphadenopathies, and a solid mass in the right thigh. Initially, the patient was diagnosed with a malignant vascular tumor regarding the expression of vascular markers from the biopsy of the right thigh lesion that was performed after the inconclusive bone marrow biopsy. The second bone marrow biopsy, which was performed due to the partial response to sarcoma treatment, showed hypercellular bone marrow with CD34 and CD61-positive spindle cell infiltration and > 20% basophilic blasts with cytoplasmic blebs. RNA sequencing of soft tissue biopsy revealed the presence of RBM15::MRTFA(MKL1) fusion. Based on these findings, myeloid sarcoma/AML with RBM15::MRTFA(MKL1) fusion diagnosis was made. AML with RBM15::MRTFA(MKL1) fusion can initially present as extramedullary lesions and might cause misdiagnosis of non-hematologic malignancies.

Clinicopathological Features of Three Rare EWSR1::NFATC2 Sarcomas of Bone and Soft Tissues.

Certain undifferentiated round cell sarcomas displaying EWSR1::NFATC2 fusion have recently been reported, mostly in the bones. This report presents clinicopathological features of 3 additional EWSR1::NFATC2 fusion sarcomas of bone and soft tissues. We present 2 soft tissue and 1 bone tumors: A 62-year-old man with pain and a slowly growing, 8-cm-sized soft tissue mass in the anterolateral compartment of his right calf, along with multiple pulmonary metastatic lesions; a 63-year-old man with a 5-cm sized axillary mass of 4 months duration and a cystic renal mass; and a 53-year-old man with a complaint of leg pain was found to have a 2-cm diameter, intramedullary, lytic mass in the diaphysis of his left femur. Microscopic examination of the tumors in all patients revealed round to epithelioid cells arranged in cords and trabeculae in a myxohyaline stroma. Immunohistochemically, the tumor cells were positive for MIC2/CD99 (3/3), EMA (3/3), NKX3.1 (3/3), NKX2.2 (2/2), CD10 (2/2), and aggrecan (1/1), while negative for S100P and GFAP. Various keratins were also negative except focal AE1/AE3 positivity in the third tumor. By fluorescence in-situ hybridization, 2 tumors (#1 and #3) revealed EWSR1 gene rearrangement and amplification. Furthermore, 2 tumors (#1 and #2) displayed EWSR1ex8::NFATC2ex3 fusion with next-generation sequencing (NGS). The first patient was offered chemotherapy. However, he died of pulmonary metastasis. This report highlights the value of combining histopathological features and immunostains such as NXK3.1, NKX2.2, CD10, and aggrecan, along with EWSR1 testing for triaging these tumors for rare gene fusions by NGS that has prognostic implications.

A Single-Center Retrospective Analysis of Kaposi's Sarcoma: Is There a Relationship Between Emmprin/CD147 Expression and Biological Behavior?

OBJECTIVES: Emmprin (CD147/BSG) protein is estimated to play a key role in cell migration and chemoresistance in viral carcinogenesis. However, there are very limited studies investigating the CD147 in the oncogenesis of Kaposi's sarcoma-associated herpesvirus. This study aims to reveal the relationship between CD147 expression with histopathological parameters, disease pattern, and recurrence in Kaposi's sarcoma (KS). METHODS: The study included 67 patients diagnosed with KS between January 1982 and September 2023. Clinical and histopathological features were analyzed retrospectively. HHV-8, CD31, and CD147 expressions were evaluated by immunohistochemistry. RESULTS: Sixteen (24%) female and 51 (76%) male patients with median age of 64 (10-86) were included in the study. CD147 was positive in 57 (85%) cases and associated with nodular pattern (P = .001), presence of solid/fibrosarcomatous area (P = .005), and high mitotic activity (P = .035). The disease relapsed in 17 (27%) of the 63 patients with median 2 (0-12) years follow-up. While a 5-year relapse-free survival was 48.5% in the CD147 diffuse positive group, it was 83.4% in focal positive and 100% in negative cases (P = .029). CONCLUSION: Our study exhibited the relationship between CD147 overexpression and recurrence in KS, but the inhomogeneity of the treatment groups and the small number of patients should also be considered. These findings may provide insight into the pathogenesis of KS and the development of targeted therapies in the future.

Epstein-Barr Virus-Positive Leiomyosarcoma in Immunocompetent Patients.

OBJECTIVE: Epstein-Barr Virus-Associated Smooth Muscle Tumor (EBV-SMT) is a rare tumor with a higher rate of occurrence in unusual locations in the setting of immunodeficiency. In this study, we evaluated a cohort of ordinary leiomyosarcomas (LMS) for the presence of EBV and described the clinicopathological features deviating from routinely diagnosed cases of EBV-SMT. MATERIAL AND METHOD: The sections of tissue microarrays including 93 classical LMS occurring in various locations were hybridized with EBER and stained for LMP1 antibody using the Leica Bond Autostainer. EBV real-time PCR assay was performed in 2 EBER-positive cases. RESULTS: Among the 93 LMS cases, 2 non-uterine cases (2.2%) were positive for EBER and negative for LMP1, and were referred to as `EBV-positive LMS`. Both were females in their 6th decade without immunosuppression. EBV real-time PCR assay revealed the presence of EBV in one of the cases. Tumors were located in the pancreas and chest wall. Morphologically, tumors were rather myxoid, multinodular, and composed of long fascicles of spindle cells with intermediate- to high-grade features. High mitotic activity and focal necrosis were present, whereas no accompanying lymphocytes were detected. One of the patients developed metastatic disease after 3 years. CONCLUSION: EBV-positive LMS occurring in immunocompetent patients has features distinct from classical EBV-SMT seen in immunosuppressed patients.

Alamandine treatment prevents LPS-induced acute renal and systemic dysfunction with multi-organ injury in rats via inhibiting iNOS expression.

Sepsis is defined as the dysregulated immune response leading to multi-organ dysfunction and injury. Sepsis-induced acute kidney injury is a significant contributor to morbidity and mortality. Alamandine (ALA) is a novel endogenous peptide of the renin-angiotensin-aldosterone system. It is known for its anti-inflammatory and anti-apoptotic effects, but its functional and vascular effects on sepsis remain unclear. We aimed to investigate the effects of ALA, as a pre- and post-treatment agent, on lipopolysaccharide (LPS)-induced systemic and renal dysfunction and injury in the LPS-induced endotoxemia model in rats via functional, hemodynamic, vascular, molecular, biochemical, and histopathological evaluation. 10 mg/kg intraperitoneal LPS injection caused both hepatic and renal injury, decreased blood flow in several organs, and renal dysfunction at 20 h in Sprague-Dawley rats. Our results showed that ALA treatment ameliorated systemic and renal inflammation, reduced inflammatory cytokines, prevented the enhancement of the mortality rate, reversed vascular dysfunction, corrected decreased blood flows in several organs, and reduced renal and hepatic injury via inhibiting iNOS (inducible nitric oxide synthase) and caspase expressions in the kidney. In addition, expressions of different ALA-related receptors showed alterations in this model, and ALA treatment reversed these alterations. These data suggest that ALA's systemic and renal protective effects are achieved through its anti-inflammatory, anti-pyroptotic, and anti-apoptotic effects on hemodynamic and vascular functions via reduced iNOS expression.

EWSR1::POU2AF3(COLCA2) Sarcoma: An Aggressive, Polyphenotypic Sarcoma With a Head and Neck Predilection.

EWSR1::POU2AF3 (COLCA2) sarcomas are a recently identified group of undifferentiated round/spindle cell neoplasms with a predilection for the head and neck region. Herein, we report our experience with 8 cases, occurring in 5 men and 3 women (age range, 37-74 years; median, 60 years). Tumors involved the head/neck (4 cases), and one each the thigh, thoracic wall, fibula, and lung. Seven patients received multimodal therapy; 1 patient was treated only with surgery. Clinical follow-up (8 patients; range, 4-122 months; median, 32 months) showed 5 patients with metastases (often multifocal, with a latency ranging from 7 to 119 months), and 3 of them also with local recurrence. The median local recurrence-free and metastasis-free survival rates were 24 months and 29 months, respectively. Of the 8 patients, 1 died of an unknown cause, 4 were alive with metastatic disease, 1 was alive with unresectable local disease, and 2 were without disease. The tumors were composed of 2 morphologic subgroups: (1) relatively bland tumors consisting of spindled to stellate cells with varying cellularity and fibromyxoid stroma (2 cases) and (2) overtly malignant tumors composed of nests of "neuroendocrine-appearing" round cells surrounded by spindled cells (6 cases). Individual cases in the second group showed glandular, osteogenic, or rhabdomyoblastic differentiation. Immunohistochemical results included CD56 (4/4 cases), GFAP (5/8), SATB2 (4/6), keratin (AE1/AE3) (5/8), and S100 protein (4/7). RNA sequencing identified EWSR1::POU2AF3 gene fusion in all cases. EWSR1 gene rearrangement was confirmed by fluorescence in situ hybridization in 5 cases. Our findings confirm the head/neck predilection and aggressive clinical behavior of EWSR1::POU2AF3 sarcomas and widen the morphologic spectrum of these rare lesions to include relatively bland spindle cell tumors and tumors with divergent differentiation.

Multinucleated tumor cells in clear cell renal cell carcinoma.

OBJECTIVES: Multinucleated tumor cells (MTCs) in clear cell renal cell carcinoma (ccRCC) are not well understood. METHODS: Our study included ccRCC cases in a single institution between 2010 and 2019. We classified MTC as MTC with degenerative atypia (MTCD), MTC with no anaplasia (MTCNA), and MTC with anaplasia (MTCA). Clinicopathologic characteristics and outcomes were compared between MTC groups. RESULTS: In all, 92 of 256 people (36%) with ccRCC had MTC. People with ccRCC with MTCD and those with ccRCC but no MTC had similar clinicopathologic characteristics and outcomes. Also, MTCNA and MTCA were associated with larger tumor size, advanced pathologic tumor stage, higher World Health Organization/International Society of Urologic Pathologists nuclear grade, and higher metastatic potential (P < .001 for each parameter). Overall, MTCA was associated with an increased rate of recurrence (P = .004), higher metastatic potential (P < .001), and shorter time to metastasis (P = .033), regardless of tumor stage. Univariate Cox regression revealed MTCNA as a significant predictor of metastasis at 5 years (hazard ratio [HR], 4.171; 95% CI, 1.934-8.998); moreover, MTCA was a significant predictor of recurrence (HR, 5.723; 95% CI, 2.495-13.124), metastasis (HR, 12.024; 5.966-24.232), and death (HR, 5.661; 95% CI, 2.688-11.924) at 5 years. CONCLUSIONS: Although MTCD may not be relevant in tumor grading, MTCNA and MTCA are associated with adverse outcomes.

Comparison of Uncultured Cell Spray and Split-Thickness Skin Grafting in Deep Partial-thickness Burns: A Novel Animal Model.

OBJECTIVE: To compare uncultured cell spray and conventional surgery in deep second-degree burns in rats and create an experimental model for the use of this method. STUDY DESIGN: An experimental study. Place and Duration of the Study: Hacettepe University Experimental Animals Application and Research Center, Ankara, Turkey, from October 2018 to December 2020. METHODOLOGY: Twenty-four Wistar albino rats were divided into 4 groups. Two deep second-degree burns were created on the dorsal skin in different locations. On the 5th day of the burn wound, a split-thickness skin graft was applied to one of the burn wounds with half of the donor graft. Two-stage enzyme application was performed on the other half of the donor graft and keratinocytes were applied as a spray to the other tangential excision burn wound. Samples taken by excisional biopsy on certain days were examined macroscopically and histologically. RESULTS: In all the experimental groups according to sacrification days, macroscopic healing percentages, non-epithelised areas, inflammation and neovascularisation scoring were similar between graft side and spray side. CONCLUSION: The effects of conventional split-thickness skin graft and uncultured cell spray on wound healing were comparable, suggesting that the uncultured cell spray method can be used as an alternative method to the classical burn treatment. KEY WORDS: Deep second-degree burn, Grafting, autologous cell, Non-cultured cell spray, Keratinocyte.

Can endocan serve as a molecular "hepatostat" in liver regeneration?

BACKGROUND: Intriguingly, liver regeneration after injury does not induce uncontrolled growth and the underlying mechanisms of such a "hepatostat" are still not clear. Endocan, a proteoglycan, was implicated in liver regeneration. It can support the function of hepatocyte growth factor/scatter factor in tissue repair after injury. Endostatin, a 20 kDa C-terminal fragment of collagen XVIII, may modulate the cessation of liver regeneration. eEF2K, a protein kinase that regulates protein synthesis, can regulate angiogenesis. Thus, we investigated the role of endocan, endostatin and eEF2K during normal liver regeneration. METHODS: Serum samples and regenerating remnant liver tissues were obtained on various days after partial hepatectomy in rats. mRNA expression levels of Vegf and Pcna were analyzed in addition to immunohistochemical evaluations. Liver tissue protein levels of endostatin, endocan and p-eEF2K/eEF2K were determined with Western blot. Serum levels of endostatin and endocan were assessed with ELISA. RESULTS: Pcna expression level in residual liver tissues peaked on day-1, while Vegf expression reached its highest level on days 1-3 after partial hepatectomy (70%). Endocan activity declined gradually on days 1-7. The decrease in liver endocan expression was accompanied by an increase in serum endocan levels. Partial hepatectomy induced a rapid increase in liver endostatin levels. Following its surge on day-1, endostatin expression gradually declined, which was accompanied by a peak in serum endostatin. Finally, partial hepatectomy was shown to regulate eEF2K; thus, increasing protein translation. CONCLUSIONS: We revealed possible mechanistic insights into liver regeneration by examining the associations of Pcna, Vegf, endocan, endostatin, eEF2K with hepatic regeneration after partial hepatectomy. Indeed, endocan might serve as a useful biomarker to monitor clinical prognosis in a plethora of conditions such as recovery of donor's remaining liver after living-donor liver transplant. Whether endocan might represent a strategy to optimize liver regeneration when given therapeutically needs to be investigated in future studies.

Spectrum of Histopathological, Immunohistochemical, Molecular and Radiological Features in 12 Cases of BCOR::CCNB3-positive Sarcomas With Literature Review.

Introduction BCOR::CCNB3-positive undifferentiated sarcomas are rare. Herein, we present clinicopathological features including immunohistochemical and molecular data, along with the radiological profile of 12 such tumors. Methods Tumors were tested for BCOR::CCNB3 fusion by reverse transcription polymerase chain reaction (RT-PCR) technique. Eight tumors were tested for EWSR1 and three for SS18 gene rearrangements by fluorescence in situ hybridization, and two for SS18::SSX fusion by fragment analysis. Results Ten of 12 patients were male with ages ranging between 4 and 17 years (median = 13, average = 14.4). Nine tumors occurred in bones and three in soft tissues (median size = 8 cm). Four of five tumors within the appendicular bones were metadiaphyseal and appeared as permeative lesions, invariably associated with cortical thickening. Three tumors displayed mineralization. Histopathologically, the tumors comprised round to epithelioid cells with round to oval to spindle-shaped nuclei, mostly diffusely arranged in a myxoid stroma with intervening thin-walled vessels. Immunohistochemically, tumor cells were positive for BCOR (10/11), SATB2 (8/9), TLE1 (5/6), cyclinD1 (4/4), and EMA (3/8). All tumors revealed BCOR::CCNB3 fusion transcript. Nine patients underwent neoadjuvant chemotherapy, including five who underwent surgical resection, with two patients, who received adjuvant radiation therapy. A single patient, each, underwent palliative chemotherapy and palliative radiotherapy, respectively. Four patients developed pulmonary metastasis and three developed local recurrences. Four patients were alive-with-disease and two were free-of-disease. Conclusions It is crucial to identify BCOR::CCNB3 fusion-positive sarcomas, given significant treatment-associated implications. Certain clinicoradiological, histopathological features, absent EWSR1 rearrangement and BCOR, SATB2, and TLE1 immunoexpression are useful for triaging these tumors for molecular testing. A review of the literature on these ultra-rare tumors, including their diagnostic mimics is presented.

Impact of Variant Histology on Clinical and Pathological Outcomes in Patients with the Upper Urinary Tract Urothelial Carcinoma.

Objectives: The objective of the study was to determine the effect of variant histology on pathological outcomes and survival in patients operated for the upper urinary tract urothelial carcinoma (UTUC). Methods: Data of 128 patients who were operated for UTUC between 2001 and 2019 were retrospectively analyzed. Patients with pure urothelial carcinoma and patients with variant histology were compared in terms of demographics, pathological outcomes, and survival. Results: The mean age of the patients was 65±11 years, female to male ratio was 30/98 and median follow-up period was 26.5 (1-176) months. Variant histology was detected in 14.8% of patients. Variant histology was found to be associated with surgical margin positivity, lymph node metastasis, presence of lymphovascular invasion, high tumor stage and grade (p=0.001, p=0.012, p=0.001, p=0.002, and p=0.009, respectively). Three-year cancer-specific and overall survival rates were 79.6% and 77.3%, respectively. There was no statistically significant relationship between variant histology with cancer-specific and overall survival (p=0.514 and p=0.515, respectively). Conclusion: Variant histology of UTUC was found to be associated with locally advanced disease, but its effect on survival could not be demonstrated.

Comparison of Cromolyn Sodium, Montelukast, and Zafirlukast Prophylaxis for Capsular Contracture.

BACKGROUND: Capsular contracture is the most common complication following breast augmentation. Recently, prophylaxis studies aiming to inhibit the release of profibrotic substances to prevent capsular contracture have gained in importance. This study investigated the effects of cromolyn sodium, montelukast, and zafirlukast on capsular contracture in a rat model. METHODS: Thirty female Wistar albino rats were randomly divided into five groups: control, sham, cromolyn sodium, montelukast, and zafirlukast. Intraperitoneal injections were administered daily to the sham (1 ml per day), cromolyn sodium (10 mg/kg per day), montelukast (10 mg/kg per day), and zafirlukast (1.25 mg/kg per day) groups 1 month before surgery. Miniature breast implants were then placed on the backs of the rats in each group. Injections were continued for the next 3 months. The rats were subsequently killed, and the capsules were harvested and assessed histopathologically. The histopathologic outcomes were acute inflammation status, inflammation severity, synovial metaplasia, foreign body reaction, mast cell count, and capsular thickness. RESULTS: The cromolyn sodium, montelukast, and zafirlukast groups had less acute inflammation and lower mean inflammation severity scores, foreign body reaction occurrence, mast cell counts, and capsular thickness than the control and sham groups ( p < 0.05). These parameters were better in the cromolyn sodium group than in the montelukast and zafirlukast groups ( p < 0.05). CONCLUSIONS: Cromolyn sodium appears to inhibit capsular contracture more efficiently than montelukast and zafirlukast. This report may be a pioneer study for the prophylactic use of cromolyn sodium in capsular contracture. CLINICAL RELEVANCE STATEMENT: The prophylactic administration of cromolyn sodium appears to reduce capsular contracture more efficiently than that of montelukast and zafirlukast. This report might constitute a pioneer study for the prophylactic use of cromolyn sodium in capsular contracture.

Adamantinoma with a Prominent Spindle Cell Component Mimicking Intraosseous Synovial Sarcoma: Clinicopathological Features of Six Tumors.

Introduction. Adamantinoma is sub-classified into classic/biphasic, osteofibrous dysplasia-like, and de-differentiated type. We present six adamantinomas with a prominent spindle cell component mimicking intraosseous synovial sarcomas. Methods. Six patients were either referred with a diagnosis of intraosseous synovial sarcoma or wherein synovial sarcoma was a differential diagnosis. Three tumors were tested for SS18 gene rearrangement by FISH and two for SS18::SSX fusion by RT-PCR technique. Results. There were three males and three females with an average age of 20.6 years. Radiologically, the lesions were expansile and showed lytic and/or sclerotic components, involving the cortex and/or medulla. Five lesions occurred in the tibia and two in the fibula. Two tumors displayed soft tissue extension and two occurred as multifocal lesions. Two patients were diagnosed with synovial sarcoma and a single patient with sarcomatoid carcinoma, elsewhere. Two "in-house" patients were initially diagnosed with synovial sarcomas. On review, all tumors were cellular comprising monomorphic spindle-shaped cells arranged in sheets and fascicles (n = 6), including a "herringbone-like" pattern (n = 3), focal tubules (n = 1), cohesive nests (n = 5), cords (n = 2), including pseudocystic component (n = 2). Immunohistochemically, tumor cells were positive for p63 (6/6), p40 (4/4), EMA (2/3), AE1/AE3 (5/6), various keratins (2/2), and TLE1 (2/4). Three tumors tested for SS18 rearrangement were negative, while two tumors tested for SS18::SSX fusion were negative. Conclusions. Adamantinomas with spindle cell morphology display overlapping features with synovial sarcoma. A clinico-radiological index of suspicion immunostains (p63 and p40) and molecular test for t(X; 18) translocation are useful in an exact diagnosis, which has treatment-related implications.