Thin-walled Vessels Research Articles

Cervical angiofibroma of soft tissue: A rare case report with literature review.

Angiofibroma of soft tissue (AFST) is a rare benign fibrous tumor recently included in the 2020 WHO classification of soft tissue and bone tumors. Currently, there are limited reports on AFST, and pathologists lack sufficient understanding of its clinical and pathological characteristics. There is scarce literature available on AFST in the cervical region. We presented a case of a 49-year-old woman who was admitted to our hospital for emergency treatment due to vaginal bleeding and fatigue. Ultrasound revealed a 63 × 27 mm hypoechoic mass extending from the cervical opening to the external opening, with a hemoglobin level of 58.0 g/L on blood routine. The tissue exhibited a pale-yellow mucinous appearance with distinct tissue boundaries and a fibrous capsule under a microscope. HE staining revealed spindle-shaped fibroblast-like cells with a consistent morphology, thin-walled branching small blood vessels, and dilated blood vessels. Regions with abundant cells and areas with sparse cells were alternately distributed and migrated gradually. Immunohistochemical analysis indicated positive expression of P53, desmin, progesterone receptor, estrogen receptor, epithelial membrane antigen, vimentin, CD68, CD163 in the tumor, but negative expression of P16, S-100, smooth muscle actin, CD117, CD10, STAT-6. CD34 was negative in the tumor cells but positive in the vascular endothelium. The Ki-67 index value was 5%. Pathological examination confirmed a soft tissue angiofibroma of the cervix. Emergency hysteroscopic surgery was performed following infusion of 3 units of packed red blood cells. A local excision of the cervical mass was performed. A 1-month follow-up ultrasound showed no abnormal mass in the cervical canal, and there have been no signs of recurrence to date. Cervical angiofibroma of soft tissue is a rare tumor with a benign clinical manifestation, minimal local recurrence, and no significant metastatic potential. Treatment primarily involves local resection with a focus on achieving negative surgical margins. By presenting this case, we aim to enhance the diagnostic and differential diagnostic capabilities of pathologists in identifying uterine tumors and preventing misdiagnosis.

Superficial angiomyxoma-like myxofibrosarcoma

Abstract Introduction/Objective Myxofibrosarcoma comprises a spectrum of malignant fibroblastic neoplasms with variably myxoid stroma, pleomorphism, and a distinctive curvilinear vascular pattern. Herein we describe a case of myxofibrosarcoma with unusual histological features that could be deceptive, mimic superficial angiomyxoma and make the diagnosis challenging Methods/Case Report A 74-year-old female presented with a right upper arm lesion that had been present for 10-12 months and had significantly increased in size over this time and became painful. There was no history of trauma. Examination demonstrated approximately 3 cm multinodular mass along the anterior aspect of the proximal arm. There were no overlying skin discolorations or ecchymosis. The patient underwent a shave biopsy and then resection. Grossly, the lesion was gray-white firm with an ill-defined border covered with a tan-white skin ellipse. Histologically, the lesion was located in the dermis extending to the dermal-epidermal junction. The lesion comprised mainly of myxoid stroma, arborizing, and plexiform thin-walled blood vessels, stellate to spindled cells with enlarged hyperchromatic nuclei, and eosinophilic cytoplasm in addition to the presence of stromal neutrophils and hyperplastic overlying squamous epithelium. The morphologic appearance elicited the differential diagnosis of superficial angiomyxoma and low-grade myxofibrosarcoma. While many features were more suggestive of superficial angiomyxoma, the degree of atypia and mitotic activity (12/10 HPF) was outside the realm of angiomyxoma and warranted the diagnosis of myxofibrosarcoma Results (if a Case Study enter NA) NA Conclusion Although rare, myxofibrosarcoma may rarely extend to the dermal-epidermal junction and mimic superficial angiomyxoma. The presence of cytologic atypia and increased mitotic activity favors myxofibrosarcoma

TFE3-rearranged perivascular epithelioid cell tumors: a clinicopathological analysis of eight cases

Objective: To investigate the clinicopathological, immunohistochemical and molecular genetic characteristics of TFE3-rearranged perivascular epithelioid cell tumor (PEComa). Methods: Eight cases of PEComa with TFE3 rearrangement diagnosed in the First Affiliated Hospital of Air Force Medical University from January 2014 to July 2022 were collected. Three were consultation cases and 5 were collected from our hospital; 7 cases were resection specimens and 1 case was a needle biopsy specimen. Routine histolopathological analysis, immunohistochemical staining, fluorescence in situ hybridization (FISH) and the next-generation sequencing were performed. Clinical data were collected and the prognosis was assessed. Results: The 8 patients consisted of 5 females and 3 males with a median age of 45 years (ranged from 25 to 65 years). The tumor location included 1 uterus, 1 liver, 1 urachus, 2 kidneys, 1 abdominal cavity, 1 colon, and 1 retroperitoneum (3 subsequent recurrences in the abdominal cavity, pelvis and ovary, and abdominal cavity, respectively). Morphologically, the tumor cells were uniform and epithelioid with translucent or eosinophilic cytoplasm. They were arranged in nests or sheets, most of which were separated by thin-walled blood vessels. There were no papillary structures, and no overt smooth muscle or fat components. Atypical features were seen in 3 cases, with bizarre nuclei and tumor giant cells. Large areas of necrosis were visible, and mitosis was common (up to 28/50 HPF). Melanin deposition was present in 3 cases. Immunohistochemical staining showed diffuse and strong positivity for TFE3 in 8/8 cases and for HMB45 in 6/8 cases; focal positivity for Cathepsin K and Melan-A in 6/8 cases and for SMA in 2/8 of cases. All cases were negative for CKpan, PAX8 and Desmin. TFE3 gene break-apart was detected by FISH in all 8 cases, 4 of which underwent next-generation sequencing, and it revealed that 2 cases presented with SFPQ::TFE3 fusion, 1 case with ASPSCR1::TFE3 fusion, and 1 case with no chimeric fusion. Seven cases were followed up for 4-94 months. All cases were alive; 4 cases were disease-free, 2 cases showed recurrence, and 1 case had metastasis at initial diagnosis. Conclusions: TFE3-rearranged PEComa has unique histomorphological, immunohistochemical and molecular characteristics. The biological behavior is aggressive, which could lead to recurrence and metastasis, and warrants close clinical follow-up.

Cavernous Malformations of the Central Nervous System: A Comprehensive Review of Pathophysiology, Diagnosis, and Management.

Cavernous malformations (CMs) of the central nervous system (CNS) are vascular anomalies characterized by clusters of dilated, thin-walled blood vessels prone to leakage and hemorrhage. These malformations can occur throughout the CNS, including the brain and spinal cord, and present with a wide range of clinical manifestations, from asymptomatic cases to severe neurological deficits. Advances in neuroimaging, particularly magnetic resonance imaging (MRI), have greatly improved the diagnosis and understanding of CMs, enabling more precise differentiation from other vascular lesions. The management of CMs has evolved alongside advancements in surgical and radiosurgical techniques, offering various therapeutic options depending on the lesion's characteristics and patient symptoms. While conservative management is often appropriate for asymptomatic or minimally symptomatic lesions, surgical resection or stereotactic radiosurgery may be indicated in cases with recurrent hemorrhage or significant neurological impairment. This comprehensive review explores the pathophysiology, clinical presentation, diagnosis, and management of CMs, highlighting current evidence-based practices and emerging therapeutic approaches. The review also addresses the genetic and molecular underpinnings of CMs, particularly in hereditary cases, and discusses potential future directions in research and treatment. By synthesizing the latest knowledge in the field, this review aims to enhance clinical decision-making and promote further investigation into the optimal management of CMs in the CNS.

Shock Response of Water-Protected Spherical Explosion Containment Vessels

Abstract Explosion containment vessels (ECVs) are important equipment used for underwater explosion experiment research. In this paper, a method is proposed to improve the blast resistance of the ECV by placing it in the water medium. The shock response caused by the underwater explosion in a spherical ECV is studied. The single-layer thin-walled spherical vessel shell submerged in an infinite domain water medium is deduced and simplified as a single-degree-of-freedom elastic vibration system with viscous damping. The underwater explosion shock wave is simplified to an exponential shock loading, and the analytical solutions of the radial shock vibration of the spherical shell are obtained using Duhamel's integrals. Compared with the numerical simulation results, the accuracy of the theoretical model is verified. The study results show that the water medium radiates out vibration energy and plays an important role in eliminating vibration through damping. It is found that the vibration damping ratio can be controlled by adjusting the vessel radius and thickness, so that the vibration of the shell can be controlled within three periods and the impact fatigue can be reduced. In addition, the radiation damping of the water medium greatly reduces the maximum radial displacement of the spherical shell, which significantly improves the blast resistance of the spherical shell.

Fabrication, characterization and numerical validation of a novel thin-wall hydrogel vessel model for cardiovascular research based on a patient-specific stenotic carotid artery bifurcation

In vitro vascular models, primarily made of silicone, have been utilized for decades for studying hemodynamics and supporting the development of implants for catheter-based treatments of diseases such as stenoses and aneurysms. Hydrogels have emerged as prominent materials in tissue-engineering applications, offering distinct advantages over silicone models for fabricating vascular models owing to their viscoelasticity, low friction, and tunable mechanical properties. Our study evaluated the feasibility of fabricating thin-wall, anatomical vessel models made of polyvinyl alcohol hydrogel (PVA-H) based on a patient-specific carotid artery bifurcation using a combination of 3D printing and molding technologies. The model’s geometry, elastic modulus, volumetric compliance, and diameter distensibility were characterized experimentally and numerically simulated. Moreover, a comparison with silicone models with the same anatomy was performed. A PVA-H vessel model was integrated into a mock circulatory loop for a preliminary ultrasound-based assessment of fluid dynamics. The vascular model's geometry was successfully replicated, and the elastic moduli amounted to 0.31 ± 0.007 MPa and 0.29 ± 0.007 MPa for PVA-H and silicone, respectively. Both materials exhibited nearly identical volumetric compliance (0.346 and 0.342% mmHg−1), which was higher compared to numerical simulation (0.248 and 0.290% mmHg−1). The diameter distensibility ranged from 0.09 to 0.20% mmHg−1 in the experiments and between 0.10 and 0.18% mmHg−1 in the numerical model at different positions along the vessel model, highlighting the influence of vessel geometry on local deformation. In conclusion, our study presents a method and provides insights into the manufacturing and mechanical characterization of hydrogel-based thin-wall vessel models, potentially allowing for a combination of fluid dynamics and tissue engineering studies in future cardio- and neurovascular research.

Infantile Fibrosarcoma Presenting as Neck Mass: A Case Report

Abstract A one year old boy presented with a mass in the posterior triangle of left side of neck for ten months with rapid increase in size since one month. Radio-imaging was done. He underwent surgery, the mass was excised and the histopathological examination was done. Clinically, it was thought to be as schwannoma. Tumor measured 10 x 8 x 6 cm approximately, fixed with underlying tissue, venous prominence seen on bosselated surface and was non-tender. Microscopically, showed a cellular neoplasm composed of spindle cells arranged in herringbone pattern, also as fascicles and bundles, with focal area showing slit like thin-walled vessels simulating hemangiopericytoma like vasculature. Focally, shows infiltration of muscle and fat. Immunohistochemistry study was performed. Correlating histology with clinical, radiology and immunohistochemistry findings, the patient was diagnosed as a case of Infantile Fibrosarcoma of neck region, a relatively rare malignant fibroblastic tumor, occurring mostly in infancy, often misdiagnosed with benign tumor. Keywords: Cellular, herringbone pattern, hemangiopericytoma, immunohistochemistry, fibroblastic.

A computational approach to modeling flow-induced large deformation of thin-walled compliant vessels

We present a computational method capable of modeling 3D flow-induced deformation of thin, highly compliant, hyperelastic vessels conveying viscous, inertial fluid. The method can uniformly consider vessel extension and collapse. Very large inflation, transient deformation, complex flow features as well as highly complex buckling shapes are well resolved by this method. The methodology combines finite volume and spectral methods for fluid motion, finite element method for structural mechanics of the vessel wall, and the immersed boundary method for two-way coupling between the wall and fluid. A hybrid of the continuous forcing and the ghost node methodologies capitalizing on the strengths of each is developed. The method avoids the surface instability encountered with the continuous forcing methods, as well as the need for domain remeshing as required in the iterative and partitioned approaches. The vessel wall can follow linear or nonlinear (strain softening and hardening) material models, and the fluid inertia can vary over a wide range. We demonstrate the versatility of the method by considering vessel inflation and collapse with large, complex, and transient deformation. Remarkable differences in vessel inflation at low versus moderate inertia are observed; this includes steady versus oscillatory motion, emergence of flow recirculation and pressure wave reflection which are well resolved. For the collapsing vessels, well-defined shapes with different buckling modes as well as highly complex buckling with fine surface folds are predicted. Additionally, a second-order correction to the well-known law of Laplace is developed and used to validate our computational results for vessel inflation.

Feasibility study of measures to master a new technology for manufacturing thin-walled large-size bottoms by flanging (in conditions of «Atommash» the branch of «AEM-Technologies» JSC in Volgodonsk)

The object of research in this article is the «Atommash» the branch of «AEM-Technologies» JSC in Volgodonsk, an organisation that was designed and commissioned in 1976 as the head machine-building enterprise for the production of a complete set of hull and heat-exchange equipment for NPP power unit in the volume of the nuclear island. The subject area chosen is the organisation of production of large-size products, which the enterprise intends to diversify through the acquisition of a line for the manufacture of thin-walled bottoms of large-size pressure vessel housings for NPPs and oil and gas chemistry. The purpose of the research is to develop a project for the development of new technological capacities based on the analysis of existing technologies and methods of production, which will increase the efficiency of production activities at the «Atommash» the branch of «AEM-Technologies» JSC in Volgodonsk. The main methods in writing the article were theoretical analysis of scientific literature on the research problem, graphical method and study of local documentation of the research object in terms of modernisation of production facilities. The main result of the research is the conclusion about the necessity of introducing a new technology – cold rolling (flanging) in order to expand the technological capabilities of the enterprise, to increase the efficiency of production in this area, to gain profit from the supply of thin-walled vessel bottoms to other enterprises to replace European suppliers, and as a consequence an increase in competitive advantage.

O10 Multifocal congenital haemangiomas: expanding our understanding of “neonatal haemangiomatosis” – case series

Abstract Background Congenital haemangiomas are benign vascular tumours, typically solitary, categorised by their postnatal behaviour as rapidly involuting, non-involuting, or partially involuting. Histologically, they differ from infantile haemangiomas by the lack of immunostaining for GLUT-1. We present three infants with congenital, small, multifocal, non-progressive haemangiomas on the skin. Cases Our first patient was a male, born with 18 small vascular lesions. Abdominal ultrasound showed three vascular lesions in his liver and one in his left kidney, which were not visible on the repeated ultrasound in 3 months. MRI of the thorax showed a vascular lesion in the right hemithorax. He was completely asymptomatic, and the lung lesion was monitored annually with ultrasound. The second patient was a male, born with eight vascular lesions. He had an abdominal ultrasound, which was clear. He was also asymptomatic, and the lesions disappeared in the first year. The third patient was a female, born with 24 vascular lesions. Cranial ultrasound was clear; however, MRI head revealed nine punctate white matter lesions suggestive of vascular lesions. She had three small foci in the liver, consistent with haemangiomas, which were not detected after 6 weeks. All three patients had skin biopsy, which showed thin-walled dilated vessels in the dermis, negative for GLUT1 and D240. None of the patients had coagulopathy. Conclusion These three cases expand the diagnosis of congenital haemangioma to include a multifocal phenotype and demonstrate their possible association with visceral and intracranial lesions/abnormalities.

Pulmonary hemorrhage in cystic fibrosis: a review of current data

Pulmonary hemorrhage is a serious complication of cystic fibrosis (CF) with a prevalence up to 9.1%. According to the Registry of Patients with Cystic Fibrosis of the Russian Federation for 2020, the prevalence of pulmonary hemorrhage was 1.5% in the general population, and 6.5% in patients over 18 years of age. Despite the importance of this problem, there is no systematic information on pulmonary hemorrhage in CF.Aim. The purpose of this study was to review current data on the pathogenesis, risk factors, and approaches to the treatment of pulmonary hemorrhage in patients with CF. Information was searched in еLibrary and PubMed databases.Results. During the literature review, we summarized and systematized the collected scientific data on pulmonary hemorrhage in CF. The pathogenesis of pulmonary hemorrhage is chronic inflammation in the bronchial wall accompanied by increased angiogenesis factors that promote neovascularization with development of many tortuous, thin-walled vessels. Exacerbation of bronchial inflammation and mechanical strain contribute to erosion and damage of fragile vessels and cause the bleeding. The main risk factors for pulmonary hemorrhage were colonization with Pseudomonas aeruginosa, Staphylococcus aureus, diabetes mellitus, and FEV1 < 70%. Complex therapy for pulmonary hemorrhage includes the use of antibiotics and antifibrinolytic agents. Some of the published regimens use β-blockers and blood coagulation factor VII. Data on the efficacy of vitamin K are unclear, but it is also used in the treatment of pulmonary hemorrhage. In cases of massive bleeding, temporarily discontinuation of inhalations of hypertonic solution and kinesiotherapy is recommended. In case of recurrent massive bleedings, bronchial artery embolization is performed and lung resection can be done in extreme cases.Conclusion. Hemoptysis in CF is a complex clinical problem that requires a multidisciplinary approach. Currently, important aspects of the pathogenesis of pulmonary hemorrhage remain unclear. Given the increasing life expectancy of CF patients and the age-related risk of pulmonary hemorrhage, it is important to investigate the pathogenetic aspects of this complication for the subsequent development of effective and justified treatment algorithms.

Epitheloid Haemangioma of Spine - A Rare Case Report and Review of Literature

Introduction: Epitheloid hemangioma (EH) of spine is a rare vascular disease. Haemangiomas are tumours typically composed of thin walled blood vessels, of which EH is an infrequent variation. The exact incidence of EH is not known. EH, though is considered to be benign disease it can be locally aggressive. EH most commonly affects the integumentary system. IT most commonly involves liver, lungs and bones. Here we report a 25 years old male with complete work up for EH including clinical data, MRI spine, surgical, histopathological information and adjuvant radiation therapy following surgical management. In addition to the case report, we reviewed literature on EH of bones. Case Report: A 25 years old male came to our emergency department with complaints of severe lower back pain. He also complained of difficulty in walking for the past 3 months. MRI Lumbosacral (LS) with whole spine screening was done 1 month back and it showed Multifocal vertebral lesions involving D4, D5, D6 vertebra predominantly in posterior elements, expansion of the transverse processes and involvement of costochondral junction, left 5th rib with extensive soft tissue component indenting on the pleura. He was seen by Neurosurgery team at our hospital and was planned for surgical decompression and stabilisation of D4-D6 vertebrae. He underwent D3 to D6 laminectomy and stabilization under general anaesthesia. Final histopathology along with IHC correlation was suggestive of Epitheloid Hemangioma. Case was discussed in our hospital multidisciplinary tumor board and was planned for adjuvant radiotherapy (RT). Then he received adjuvant radiotherapy total dose (TD) 45 Gray (Gy) to D3-D6 region. Post treatment 6 months, his power is improved and is near normal. Conclusion: To summarize our case appears as a typical features of EH like young male patient, lytic lesions with sclerotic rim, IHC confirmation

Gastric glomus tumor mimicking neuroendocrine tumor on fine needle aspiration: a diagnostic pitfall

Abstract Introduction/Objective Glomus tumors (GT) are mesenchymal neoplasms of modified smooth muscle that most commonly affect subungual regions of distal extremities. Although they can occur everywhere in the body, gastric involvement is rare. Gastric GT is usually benign but given the overlapping morphologic and immunohistochemical features with other gastric mesenchymal tumors, GT is commonly misdiagnosed. Methods/Case Report We present two cases of gastric GT initially diagnosed as well-differentiated neuroendocrine tumor (WDNT), G1 on fine needle aspiration (FNA). A 57-year-old female presented with an incidental 1.5 cm gastric submucosal lesion discovered on endoscopy performed for esophageal food impaction. The second case is of a 73- year-old male with a 1.7 cm submucosal lesion found on endoscopy for reflux. Both lesions were located in the gastric antrum. FNA showed clusters of relatively uniform cells with moderate cytoplasm, round nuclei, and stippled chromatin. Tumor cells were focally positive for synaptophysin, while negative for CK7, CD117, DOG-1, and chromogranin. Ki-67 proliferative index was <3%. A diagnosis of WDNT, G1 was made. Subsequent partial gastrectomy showed a submucosal epithelioid neoplasm composed of cells with eosinophilic to clear cytoplasm, and distinct cellular membranes. Focally dilated, tumor-associated thin-walled vessels were noted. Immunohistochemically, the tumor was positive for SMA, calponin, and synaptophysin, and negative for CK AE1/AE3 and chromogranin, supporting the diagnosis of gastric GT. Results (if a Case Study enter NA) N/A Conclusion The rarity of gastric GT, combined with the morphological and immunohistochemical similarity with WDNT, led to diagnostic pitfalls in these cases. With the increased detection and sampling of incidental gastric lesions, cytopathologists should be aware of this uncommon tumor and its mimics, and as such, expand their differential diagnoses.

Methods for Estimating Hydrogen Fuel Tank Characteristics

Abstract The pressure vessels needed to store hydrogen for next-generation hydrogen fuel cell vehicles are expected to be a substantial portion of the total system mass, volume, and cost. Gravimetric capacity, volumetric capacity, and cost per kilogram of usable hydrogen are key performance metrics that the U.S. Department of Energy (DOE) uses to determine the viability of hydrogen fuel cell systems. Research and development related to hydrogen storage systems covers a wide range of potential operating conditions, from cryogenic temperatures to high temperatures (above ambient) and low pressure to high pressure. Researchers at PNNL have developed methods for estimating these key pressure vessel characteristics to support on-board hydrogen storage system design and performance evaluation and to support decision-making about DOE hydrogen storage system research investments. This article describes the pressure tank estimation methodology that has been used as a stand-alone calculation and has been incorporated into larger system evaluation tools. The methodology estimates the geometry, mass, and material cost of type I, type III, and type IV pressure vessels based on operating pressure and material strength at the system's operating temperature, using classical thin-wall and thick-wall pressure vessel stress calculations. The geometry, mass, and material cost requirements of the pressure vessel have significant impacts on the total system performance. For example, hydrogen storage materials that can separately achieve a very high hydrogen density can be deemed impractical for use in fuel cell vehicle hydrogen storage systems because the pressure tank containing them is too large, heavy, or expensive. This article describes the design philosophy and analytical process of the tank characteristic estimation methodology, which has been implemented in spreadsheet calculation tools and system-level analysis tools used by DOE researchers. Each of the three tank types (type I, type III, and type IV) uses a different analysis methodology with some common elements. This article also provides examples of implementing the methodology to perform parametric studies of all three pressure vessel types. The goal of this article is to present the methodology in sufficient detail so it can be implemented in other hydrogen fuel cell vehicle design and analysis tools.

Safety Componentry for Mitigating Catastrophic Failure in Lithium-Ion Cylindrical Cells

The lithium-ion cylindrical cell is designed as a thin-walled pressure vessel, with various engineering controls to mitigate catastrophic failure. With an increase in pressure inside the cell, given suitable can wall thickness, the cell will fail through the header componentry. A tear down and inspection method has been developed to observe the header design and componentry of cells. A range of cylindrical cells were investigated - from 18650 to 46950 in size. This involved visual inspection, x-ray tomography, chemical analysis and microscopy. The presence of safety componentry, thickness and material type is discussed; factors which affect the propensity of the cell to fail at this location. Commonly observed was the Current Interrupt Device (CID) vent disc which is designed to mechanically deform in response to pressure increase within the cell. This in turn disconnects the cell circuitry and ruptures, initiating the venting process. Furthermore, cells typically contained a Positive Temperature Coefficient (PTC) device which protects the battery from external short circuits and electrical abuse conditions by limiting current flow when the cell reaches a particular temperature. This approach clearly outlines the safety componentry and their respective functions used within these cell sizes, allowing for a better understanding of battery safety. Additionally, we expect this work to disseminate new developments in larger format lithium-ion batteries as they are being sought for better system performance.

Fibrosarcoma Presenting as Marjolin Ulcer – A Rare Case Report

Marjolin ulcer is a rare malignancy that arises in previously traumatised or chronically inflamed skin, particularly after burns, with an average latency period of 36 years. Nearly 75-90% marjolin ulcers are diagnosed as squamous cell carcinoma but other neoplasms like basal cell carcinoma, melanoma, fibrosarcoma etc have also been rarely reported. In this case, a 52-year-old male presented with a painless bleeding mass over lower chest wall rapidly increasing in size from last 2 years. He had suffered burn at the same site 20 years ago. Biopsy was reported as spindle cell neoplasm. Wide local excision revealed a poorly circumscribed subcutaneous spindle cell neoplasm exhibiting variable cellularity, fascicular to storiform architecture, mild to moderate nuclear atypia and scattered gaping thin-walled blood vessels. The neoplastic cells showed diffuse strong staining with CD34 in the less cellular area and patchy positivity in the cellular more mitotically active areas. The tumor cells were immunonegative for EMA, p63, SMA, CD99 and STAT6. The final diagnosis rendered was Dermatofibrosarcoma Protuberans dedifferentiating in to fibrosarcoma. Although sarcoma presenting as a Marjolin ulcer is exceedingly rare, it should be kept in mind in differential diagnosis of spindle cell malignancy arising at a burn site.

Unilateral vascular hamartomas of the vaginal tunic in a dog.

A 12-y-old, male Dachshund was presented for elective orchiectomy. The testes were of normal size. The left testis had numerous dark-red, blood clot-like foci within the vaginal tunic over the pampiniform plexus, epididymis, and testis. Histologically, the red foci were limited to the vaginal tunic and consisted of disorderly growing, variably sized, thin-walled blood vessels lined by a single layer of endothelial cells without mitoses and supported by a thin layer of pericytes. The blood vessels were distended by erythrocytes without thrombus formation. Endothelial cells had cytoplasmic immunolabeling for CD31; pericytes had strong cytoplasmic immunolabeling for α-smooth muscle actin. Our case of subclinical unilateral vascular hamartomas of the vaginal tunic in a dog has not been reported previously in domestic animals or humans, to our knowledge.

Expanding the Clinicopathologic and Molecular Spectrum of Lipoblastoma-Like Tumor in a Series of 28 Cases

Lipoblastoma-like tumor (LLT) is a rare adipocytic neoplasm with a predilection for the vulva. Since 2002, <30 cases have been reported, characterizing it as an indolent tumor that may sometimes recur locally. Diagnosis can be challenging due to its rarity and morphologic overlap with other adipocytic tumors. Thus far, there are no specific molecular or immunohistochemical features to aid in the diagnosis of LLT. Recent case reports have described LLT arising at other sites, including the spermatic cord and gluteal region, suggesting wider anatomical distribution. We present a large series of LLT to further characterize its clinicopathologic and molecular features. Twenty-eight cases of LLT were retrieved from departmental and consult archives (including 8 from a prior series). The cohort comprised 28 patients (8 males, 20 females) with a median age of 28 years (range: 1-80 years). There were 17 primary LLT of the vulva. Other anatomical sites included the scrotum (n = 3), spermatic cord (n = 2), inguinal region (n = 2), limbs (n = 2), pelvis (n = 1), and retroperitoneum (n = 1). Median tumor size was 6.0 cm (range: 1.8-30.0 cm). The tumors had a lobulated architecture and were typically composed of adipocytes, lipoblasts, and spindle cells in a myxoid stroma with prominent thin-walled vessels. Using immunohistochemistry, a subset showed loss of Rb expression (12/23 of samples). Follow-up in 15 patients (median: 56 months) revealed 8 patients with local recurrence and 1 patient with metastases to the lung/pleura and breasts. Targeted DNA sequencing revealed a simple genomic profile with limited copy number alterations and low mutational burden. No alterations in RB1 were identified. The metastatic LLT showed concurrent pathogenic PIK3CA and MTOR activating mutations, both in the primary and in the lung/pleural metastasis; the latter also harbored TERT promoter mutation. One tumor had a pathogenic TSC1 mutation, and one tumor showed 2-copy deletion of CDKN2A, CDKN2B, and MTAP. No biologically significant variants were identified in 8 tumors. No gene fusions were identified by RNA sequencing in 4 tumors successfully sequenced. This study expands the clinicopathologic spectrum of LLT, highlighting its wider anatomical distribution and potential for occasional metastasis. Molecularly, we identified activating mutations in the PI3K-MTOR signaling pathway in 2 tumors, which may contribute to exceptional aggressive behavior.

Lipoblastoma-Like Tumor and Fibrosarcoma-Like Lipomatous Neoplasm Represent the Same Entity: A Clinicopathologic and Molecular Genetic Study of 23 Cases Occurring in Both Men and Women at Diverse Locations

Lipoblastoma-like tumor (LLT) is a benign soft tissue tumor demonstrating mixed morphologic features of lipoblastoma, myxoid liposarcoma, and spindle cell lipoma but lacking genetic alterations associated with those tumors. LLT was originally thought to be specific to the vulva but has since been reported in the paratesticular region. The morphologic features of LLT overlap with those of “fibrosarcoma-like lipomatous neoplasm” (FLLN), a rare, indolent adipocytic neoplasm considered by some to form part of the spectrum of atypical spindle cell and pleomorphic lipomatous tumor. We compared the morphologic, immunohistochemical, and genetic features of 23 tumors previously classified as LLT (n = 17) and FLLN (n = 6). The 23 tumors occurred in 13 women and 10 men (mean age, 42 years; range, 17 to 80 years). Eighteen (78%) cases arose in the inguinogenital region, whereas 5 tumors (22%) involved noninguinogenital soft tissue, including the flank (n = 1), shoulder (n = 1), foot (n = 1), forearm (n = 1), and chest wall (n = 1). Microscopically, the tumors were lobulated and septated, with variably collagenized fibromyxoid stroma, prominent thin-walled vessels, scattered univacuolated or bivacuolated lipoblasts, and a minor component of mature adipose tissue. Using immunohistochemistry, 5 tumors (42%) showed complete RB1 loss, with partial loss in 7 cases (58%). RNA sequencing, chromosomal microarray, and DNA next-generation sequencing study results were negative for significant alterations. There were no clinical, morphologic, immunohistochemical, or molecular genetic differences between cases previously classified as LLT or FLLN. Clinical follow-up (11 patients [48%]; range, 2-276 months; mean, 48.2 months) showed all patients were alive without disease, and only one patient had experienced a single local recurrence. We conclude that LLT and FLLN represent the same entity, for which “LLT” seems most appropriate. LLT may occur in either sex and any superficial soft tissue location. Careful morphologic study and appropriate ancillary testing should allow for the distinction of LLT from its potential mimics.

Analysis of discontinuity stress at shell and elliptical head juncture using theory of beam on elastic foundation

A thin-walled pressure vessels under internal pressure generates higher amount of stresses at shell-head juncture compared to membrane stress. These localized stresses are generated due to change in the shape of the meridian. The change in shape of the meridian is seen at the head and shell junction. The discontinuity in shape changes the direction of resultant stress. To predict the accurate stresses around the discontinuity region, bending of beam on an elastic foundation is used as part of the analytical analysis. Charts have been plotted of various stresses generated near juncture. The method is applied to pressure vessel with cylindrical shell and elliptical head. The theoretical results are then compared to the analytical results obtained from finite element analysis (FEA). In the present work, the discontinuity stresses have been evaluated analytically and the same is also compared with the finite element analysis results. It is found that the results of FE analysis closely agrees with the analytical results maximum percentage variation of 1.19.