bluuebunny/crossref_metadata_2025_split huggingface dataset:
ETV6-NTRK3–Positive Inflammatory Myofibroblastic Tumor of the Ileum: Report of an Infantile Case and Review of the Differential Diagnosis of Pediatric Intestinal Polypoid Lesions
Authors: Tanaka Mio , Terada Nanako , Yoshida Misa , Shinkai Masato , Tanaka Yukichi 
Published: September 2023

Abstract
We report a case of an intestinal polyp causing intussusception in a 2-month-old boy. The resected polyp was diagnosed by histology and immunohistochemistry as an anaplastic lymphoma kinase (ALK)–negative inflammatory myofibroblastic tumor (IMT), and the ETS variant 6 (ETV6)–neurotrophic receptor tyrosine kinase 3 (NTRK3) fusion gene was detected by reverse transcription–polymerase chain reaction. Recently, histologically definitive, ALK-negative IMTs possessing the ETV6-NTRK3 fusion gene have been reported. To the best of our knowledge, this is the first case of an intestinal IMT harboring ETV6-NTRK3. In the differential diagnosis of ALK-negative IMTs or spindle cell lesions showing considerably high cellularity, ETV6 rearrangement should be considered.
Unusual Human Papillomavirus–Related Neoplasms of the Head and Neck: A Case Series and Review of Literature
Authors: Devins Kyle M. , Baloch Zubair , LiVolsi Virginia 
Published: September 2023

AbstractOropharyngeal squamous cell carcinoma accounts for the majority of human papillomavirus (HPV)–related neoplasms in the head and neck. However, recent studies have identified high-risk HPV in other, clinicopathologically distinct tumors in this region. We report a series of cases involving two unique HPV-mediated neoplasms. Human papillomavirus–related multiphenotypic sinonasal carcinoma is a locally aggressive tumor arising exclusively in the sinonasal tract with pathologic features reminiscent of high-grade adenoid cystic carcinoma. Ciliated adenosquamous carcinoma often presents as a unilateral neck mass and consists of admixed nonkeratinizing squamous cell carcinoma and glandular elements, which may be deceptively bland. Cilia are often present, which are traditionally associated with benignity and may lead to misdiagnosis as a benign branchial cleft cyst. In most cases, an oropharyngeal primary tumor is later identified. Despite aggressive features, both entities have a relatively favorable prognosis. These unusual tumors present unique diagnostic challenges that require particular attention to prevent misdiagnosis and mistreatment.
Clear Cell Tumor of the Maxilla With MAML2 and EWSR1 Gene Rearrangements: A True Hybrid or a Flourescence in Situ Hybridization Fumble?
Authors: Hamza Ameer , Yao Christopher M. K. L. , Lai Stephen Y. , Bell Diana 
Published: September 2023

Abstract
Clear cell odontogenic carcinoma and clear cell variant of mucoepidermoid carcinoma are rare and aggressive tumors that usually affect individuals in the fifth decade of life and have a predilection for the maxilla and mandible. Clear cell odontogenic carcinoma is characterized by EWSR1 gene rearrangement, whereas MAML 2 gene rearrangement is pathognomonic for mucoepidermoid carcinoma. Fluorescence in situ hybridization analysis for rearrangement of these genes can be extremely helpful in difficult cases when conventional histological distinction is not possible. Herein, we describe a unique case in which a 69-year-old man had an intraosseous maxillary tumor with clear cell morphology and fluorescence in situ hybridization analysis showing rearrangement of the MAML2 gene as well as a low-level rearrangement of the EWSR1 gene. In our opinion, this case represents a hybrid tumor harboring dual gene rearrangement.
Langerhans Cell Histiocytosis With Solitary Hepatic Involvement in an Adult Patient: Diagnosis, Transplantation, and Recurrence
Authors: Rush Natalia , Saxena Romil , Lin Jingmei 
Published: September 2023

Abstract
Langerhans cell histiocytosis (LCH) rarely involves the liver without systemic manifestations, especially in adult population. We describe an unusual case of LCH with solitary hepatic involvement. Histopathologic materials from both native and allograft specimens, including all biopsies, explant hepatectomies, and correlating clinical data accumulated over a 10-year interval, were reviewed. A 46-year-old woman presented with jaundice and pruritus. An initial workup including liver biopsy led to the diagnosis of antimitochondrial antibody–negative primary biliary cholangitis with advanced fibrosis. Within a year, the patient progressed to decompensated cirrhosis requiring transplantation. Her posttransplant course was complicated by frequent bouts of markedly elevated alkaline phosphatase and γ-glutamyl transferase with mild liver transaminases elevation. These abnormalities and the liver biopsy findings of bile duct injury and portal inflammation were thought to be acute cellular rejection. Her liver enzymes showed some improvement but never completely normalized on high-dose steroid and became elevated once the therapy stopped. Three years after transplantation, the diagnosis of LCH was established based on the histopathology and immunohistochemistry in the allograft biopsy. Four more years later, the patient lost the liver allograft and required a second transplantation. The explanted allograft revealed patchy distribution of the disease, confirming difficulty of LCH diagnosis on a liver biopsy without systemic involvement. For clinicians and pathologists, it is critical to exclude hepatic involvement by LCH before rending a diagnosis of antimitochondrial antibody–negative primary biliary cholangitis or small duct primary sclerosing cholangitis.
Adamantinoma of the Femur With High-Grade Epithelial and Sarcomatoid Components: Case Report and Review of the Literature
Authors: Sharifai Nima , Runyon R. Scott , Friedman Michael V. , Cipriano Cara A. , Chrisinger John S. A. 
Published: September 2023

Abstract
Adamantinomas are rare low-grade malignant bone tumors that are composed of epithelial cells set in an osteofibrous stroma. Osteofibrous dysplasia-like and classic forms are well known; however, sarcomatous transformation (dedifferentiation) is very rarely observed. We present the case of a 48-year-old woman who presented with a 5-cm proximal femoral lytic lesion at risk of pathologic fracture. Frozen-section evaluation demonstrated an intimate admixture of atypical squamous nests and spindle cells, consistent with metastatic sarcomatoid carcinoma, so prophylactic intramedullary nailing was completed. Postoperative clinical and radiologic evaluation failed to identify a primary carcinoma, and short-term follow-up demonstrated rapid tumor spread throughout the femur and thigh. The patient underwent hip disarticulation, and microscopic examination demonstrated areas of classic adamantinoma associated with both high-grade epithelial and sarcomatoid components. Diffuse metastatic spread was evident within seven months. Along with a description of this case, we review the clinical, radiographic, histologic, and immunophenotypic characteristics of the eight adamantinomas with high-grade sarcomatous transformation that have been previously reported in detail in the English literature, and discuss important considerations for differential diagnosis.
Intrahepatic Mass-Forming Extramedullary Hematopoiesis in a Patient With Sickle Cell Disease: Case Report and Literature Review
Authors: Al-Dalahmah Osama , De Michele Simona , Sperling David C. , O'Toole Kathleen M. , Iuga Alina C. 
Published: September 2023

Abstract
Extramedullary hematopoiesis (EMH) is characterized by the expansion of hematopoietic tissue outside the bone marrow niche. It occurs when bone marrow function is insufficient and typically presents with generalized hepatosplenomegaly. We describe a rare case of mass-forming EMH that presented as two intrahepatic lesions, radiologically well-demarcated and nonenhancing on computed tomography. On magnetic resonance imaging, the lesions appeared T1 hypointense and T2 hyperintense with restricted diffusion. The lesions were discovered at the surgical workup for acute cholecystitis in a patient with previous history notable for sickle cell disease. Given the radiological concern for a neoplastic process, an ultrasound-guided biopsy was performed and diagnosed histologically as EMH. A review of the current literature detailing the common clinical, radiological, and pathological presentation of EMH is provided.
Pancreatic Panniculitis—Not Just a Skin Disease
Authors: Crimmins Jennifer M. , Russell Devin , Samulski Teresa Danielle , Ziemer Carolyn M. , Googe Paul B. 
Published: September 2023

Abstract
Pancreatic panniculitis is a rare sequela of pancreatic disease classically presenting with tender, erythematous subcutaneous nodules involving the lower extremities. Rarer associations include involvement of the marrow, intra-abdominal fat, intrathoracic fat, and the clinical finding of joint pain. We present the case of a patient who presented with a 1-year history of intermittent nausea, bloating, and anorexia with computed tomography scan findings of a complex pancreatic cystic lesion, omental findings concerning for carcinomatosis, and ascites. She developed tender, erythematous, and hyperpigmented subcutaneous nodules on bilateral lower extremities that were first noted on admission. Pancreatic biopsy revealed pancreatic pseudocyst and laboratory findings on admission were consistent with pancreatitis and pancreatic ascites. Laparoscopic omental biopsies revealed multifocal, nodular fat necrosis and associated inflammation with no carcinoma identified. Histologically similar to the omental biopsies, a punch biopsy of skin revealed lobular fat necrosis, inflammation, and basophilic stippling by calcium consistent with pancreatic panniculitis. Given the similar histologic findings in the skin and omentum in the setting of pancreatic ascites, her omental findings were attributed to pancreatic panniculitis. This case highlights the importance of recognizing that pancreatic panniculitis can present as a systemic disorder. We highlight the laparoscopic, dermatologic, laboratory, and biopsy findings of pancreatic panniculitis to demonstrate that the pathologic findings are similar in the various organs involved.
Glial Tumors
Authors: Welsh Cynthia 
Published: September 2023

Abstract
Glial tumors comprise the majority of primary intra-axial intracranial tumors. Since its introduction in 2016, the revised fourth edition of the World Health Organization (WHO) classification of central nervous system tumors has changed the diagnostic and therapeutic approach in glial tumors (WHO Classification of Tumours of the Central Nervous System [revised fourth edition]; Lyon, France: IARC; 2016). Diffuse gliomas (WHO grades II–IV) are now molecularly stratified based on isocitrate dehydrogenase 1 or 2 mutation status and classified according to 1p/19q codeletion status into astrocytic or oligodendroglial type. Updates now occur faster than new editions of the WHO classification can be prepared, so updates are being issued by way of journal articles from a Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (Brain Pathol 2019;29(4):469–472).
A Posterior Fossa Mass in a 6-Year-Old
Authors: Baker Tiffany G. , Smith Michael T. 
Published: September 2023

Abstract
Medulloblastoma is a high-grade embryonal tumor of the central nervous system arising in the infratentorium of patients of all ages with a peak incidence in childhood. Within the last decade, advances in molecular profiling of gene expression and epigenetics have advanced general understanding of previously perceived intertumoral heterogeneity. Currently, 4 subtypes of medulloblastoma are recognized: wingless (WNT)–activated, sonic hedgehog (SHH)–activated, and the non-WNT/non-SHH group, which combines groups 3 and 4. The new subgroups, which continue to evolve, have greatly complicated the process of rendering a pathologic diagnosis through integration of histopathologic and molecular data. The criterion-standard techniques for identifying these subgroups include gene expression and methylation profiling; however, such complicated and expensive laboratory techniques may not be accessible to all laboratories. Although recommendations for the approach to an integrated diagnosis have been made, no specific algorithm has been put forth. We present a case of pediatric medulloblastoma in which hematoxylin-eosin–stained tissue sections, reticulin special stain, immunohistochemistry, cytogenetics, and next-generation sequencing were implemented for the purpose of identifying subgroup and other markers of prognosis, such as TP53 mutation and MYC family member amplification. The discussion herein is aimed at reviewing current opinions on the integration of histomorphologic and molecular subgroups of medulloblastoma and providing a foundation for designing a practical and clinically meaningful approach to diagnosis.
Mass in the Meninges: Meningioma Types and Grades
Authors: Han Pengcheng , Smith Michael T. 
Published: September 2023

Abstract
Tumors of the meninges are common, probably the most common tumor of the cranial vault. Meningiomas arise from the arachnoid, but because the arachnoid and dura are frequently fused, they may appear to be of dural origin. Meningiomas frequently arise from the arachnoid cap cells, which are arachnoidal projections into dural sinuses for reabsorption of cerebrospinal fluid. This explains the frequency of meningiomas found along the dural sinuses. Meningiomas are considered benign, but recurrences are common. More frequent recurrences are found with the higher grades. Complete surgical removal is associated with a good prognosis. One study showed 20% recurrences within 20 years for meningiomas as a group (Surg Neurol 1986 26:461–469). Prognosis is closely related to surgical resection and tumor grade. This review summarizes grading in three case presentations.
A “Double-Hit” Translocation Sarcoma—First Report of the Co-occurrence of EWSR1-FLI1 and MTMR2-NTRK2 Fusion in a Small Round Blue Cell Sarcoma
Authors: Vargas Ana Cristina , Kurek Caroline , Bonar Fiona , Maclean Fiona , Qiu Min Ru , Boyle Richard , Brookwell Ross , Gill Anthony J. 
Published: September 2023

Abstract
We report a case of a 51-year-old man with primary diagnosis of Ewing sarcoma confined to the soft tissue, associated with EWSR1-FLI1 gene fusion demonstrated by fluorescence in situ hybridization (FISH). Six years after the diagnosis, immunohistochemistry for NTRK (neurotrophic receptor tyrosine kinase 1–3) was performed on this tumor using 2 Pan-Trk rabbit monoclonal antibodies, A7H6R (Cell Signaling Technology, Danvers, Mass) and EPR17341 (Abcam, Cambridge, Mass). Both clones showed diffuse moderate to strong cytoplasmic expression including presence of nuclear stain. RNA sequencing demonstrated the co-occurrence of MTMR2-NTRK2, a novel gene fusion, in the same tumor block used for EWSR1 FISH testing. While FISH for NRK2 did not confirm gene rearrangement, an atypical signal pattern was identified. This case challenges the concept that NTRK fusions are mutually exclusive with other oncogenic drivers. The clinical course of this patient has also been unusual as the tumor has followed an indolent course with no evidence of recurrent or metastatic disease.
High-Grade Gliomas in Early Adulthood: A Case-Based Review of Current Molecular Diagnostic Considerations
Authors: Canbeldek Leyla , Ames Heather M. 
Published: September 2023

Abstract
High-grade gliomas in early adulthood (between the ages of 20 and 40 years) have a wide differential diagnosis that includes entities from childhood and late adulthood. These gliomas are increasingly defined by their molecular signatures, requiring a molecular-based workup that is informed by morphology and anatomy. Here we present four cases with four different diagnoses, some rare and some common, presenting with new brain lesions. This diagnostic process is informed by the 2016 World Health Organization guidelines, c-IMPACT Now updates, and the clinico-pathologic features shown by these high-grade tumors. Particularly, we focus on practical diagnostic decisions that may need to be made with limited tissue and/or limited on-site molecular resources.
The Tale of Two Hedgehogs: Central Nervous System Embryonal Tumor Diagnosis in 3 Acts
Authors: Drake Rosanna F. , Ames Heather M. 
Published: September 2023

Abstract
Primitive embryonal tumors of the central nervous system have undergone considerable evolution in their categorization in the past century—most rapidly in the past decade with the application of molecular pathology in diagnosis. This presents numerous practical considerations when encountering one of these tumors. One may need to utilize multiple techniques to come to a prognostically accurate and actionable diagnosis. We review two cases, both with the final diagnosis of “medulloblastoma, SHH activated and TP53 wild type (World Health Organization grade IV).” These diagnoses were each arrived upon using separate, valid approaches, with consideration of the histological differential diagnosis. Immunohistochemistry, next-generation sequencing, and methylation array analysis are each presented with practical considerations of when they are most useful.
When the Horse Has Stripes: Central Nervous System Blastomycosis Presenting as a Ring-Enhancing Lesion in an Immunocompetent Patient
Authors: Hardy Naomi , Markidan Janina , Luethy Paul M. , Ames Heather M. 
Published: September 2023

Abstract
A new, single, ring-enhancing lesion in the cortex of an immunocompetent individual has a broad differential diagnosis, although primary or metastatic malignancies are usually highest on the list. The presence of inflammation without overt malignancy, however, is cause for considerations that may require ancillary testing with fresh tissue and obtaining multiple frozen samples. Central nervous system (CNS) infection with blastomycosis is a rare but potentially fatal complication, with a mortality rate approaching 20% secondary to multiple factors including delay in presentation and diagnosis (Clin Infect Dis 2010;50:797–804). What makes CNS blastomycosis so difficult to diagnose, along with other rare fungal infections, is that it can masquerade as a primary neural tumor. Infectious etiologies should always be considered in ring-enhancing lesions that show inflammation, necrosis, and no significant glial atypia on frozen section. Here we describe a case in an otherwise healthy woman, who presented with seizures and was found to have a peripherally enhancing intraparenchymal lesion on imaging. Differential diagnosis, frozen-section management, histology, and microbiology in the workup of CNS blastomycosis are discussed.
Application of Antibiotic-Impregnated Polymethyl-Methacrylate Bone Cement for the Treatment of Infected Cranioplasties
Authors: Englar Kevin M. , Kordahi Anthony M. , Brandel Michael G. , Santiago-Dieppa David R. , Wali Arvin R. , Pham Martin , Barba David , Ciacci Joseph , Rechnic Mark 
Published: September 2023

Background
Management of infected cranioplasty implants remains a surgical challenge. Surgical debridement, removal of the infected implant, and prolonged antibiotic therapy are part of the acute management. In addition, cranioplasty removal poses the risk of dural tear. Reconstruction of the cranial defect is usually delayed for several months to years, increasing the difficulty due to soft tissue contraction and scarring.

Objective
The aim of the study was to propose an alternative to delayed reconstruction in the face of infection with a dual purpose: treat the infection with a material which delivers antibiotic to the area (polymethyl-methacrylate antibiotic) and which functions as a temporary or permanent cranioplasty.

Methods
We reviewed the records of 3 consecutive patients who underwent single-stage polymethyl-methacrylate antibiotic salvage cranioplasty.

Results
All patients underwent debridement of infected tissue. Titanium mesh was placed over the bony defect. Polymethyl methacrylate impregnated with vancomycin and tobramycin was then spread over the plate and defect before closure. Patients also received extended treatment with systemic antimicrobials. Early outcomes have been encouraging for both cosmesis and treatment of infection.

Conclusions
Benefits of this treatment strategy include immediate reconstruction rather than staged procedures and delivery of high concentrations of antibiotics directly to the affected area in addition to systemic antibiotics.
Tissue Expander-Assisted Component Separation for Pediatric Abdominal Wall Reconstruction
Authors: Segal Rachel Marie , Wong Alvin , Zaldana-Flynn Michelle , Englar Kevin , Ewing Emily , Lance Samuel H. , Gosman Amanda A. 
Published: September 2023

Background
Tissue expander-assisted component separation can be used to increase the amount of skin, muscle, and fascial components available for repair of congenital abdominal wall defects via a staged approach without the need for flap reconstruction. We present the largest case series to date using a tissue expander-assisted component separation technique for treatment of congenital abdominal wall defects in a pediatric patient population.

Methods
A retrospective chart review of 9 patients with large congenital abdominal wall defects not initially amenable to primary repair between 2009 and 2020 was performed. Patients first underwent placement of tissue expanders, followed by removal once they had reached a sufficient expander volume. Component separation, with and without mesh placement, was performed to achieve abdominal wall closure.

Results
The average age of patients at primary repair was 3.2 years (SD ±1.7 years). Eight patients (88.8%) had congenital omphalocele, and 1 patient (11.1%) had gastroschisis; none were amenable to primary repair. The average size of the defects before closure was 87.6 cm2 (SD = 33.6 cm2). Eighteen tissue expanders were placed in 9 patients, 72.2% of which were placed in the plane between the external and internal oblique muscles. Patients were seen in clinic an average of 6.8 times (SD, ±3.3 visits) for volume expansion into the tissue expander, receiving an average of 32.0 mL in each per visit. An average of 4.3 months (SD, ±1.8 months) elapsed between placement and removal of the expanders. At the time of tissue expander removal and abdominal wall closure, the defects ranged from 30 to 132 cm2 (mean, 54 cm2). All defects were successfully repaired using a component separation and bilateral fasciocutaneous flap advancement. Two patients (18.2%) experienced infection of the surgical site and seroma, both of which required debridement. One patient (9.1%) experienced partial thickness skin necrosis that was managed nonsurgically. The overall complication rate was 36.4%.

Conclusions
Omphalocele and gastroschisis can produce abdominal wall defects that are not amenable to primary repair. Staged reconstruction using tissue expander-assisted component separation is a safe and effective method of obtaining adequate local soft tissue to achieve primary closure.