Steroid or pseudogout? Analysis of white deposits in tissues during surgery.

Introduction: Pseudogout is characterized by the deposition of calcium pyrophosphate crystals in the pericellular matrix of chondrocytes. Pseudogout flares can present similar to gout, osteoarthritis, septic arthritis, or prosthetic joint infection, potentially complicating post-surgical outcomes. With a high prevalence among patients undergoing arthroplasty, appropriate awareness is essential to mitigate misdiagnosis and inappropriate treatment.

Revisiting CDKN2A dysregulation in Ewing sarcoma.

Ewing sarcoma (EwS) is a rare and aggressive malignancy, which frequently affects children. One of the few recurrent genomic variants in EwS is genomic copy number deletion of CDKN2A; however, the clinical consequences of dysregulation of CDKN2A in EwS are unclear. In this study, we revisit CDKN2A to investigate its role as a potential prognostic biomarker in EwS using data from EwS pre-clinical models as well as clinical samples from patients with EwS.

Sloughing Esophagitis in the Pediatric Age Group: Clinicopathologic Characteristics of 12 Cases.

Background: Sloughing esophagitis (esophagitis dissecans superficialis) is a benign, self-limited condition of uncertain etiology. It is most common in adults; pediatric literature is limited.

Methods: Ten years of records were queried for esophageal biopsies containing terms "sloughing" and/or "dissecans.

Cell Cycle Checkpoints p16 and p21-Strong Predictors of Clinicopathologic Outcomes in High-Grade Osteosarcoma.

Purpose: In this study, we used a series of immunohistochemical measurements of 2 cell cycle regulators, p16 and p21, to evaluate their prognostic value, separately and in combination, for the disease outcomes.

Method: A total of 101 patients with high-grade osteosarcoma were included in this study. Clinicopathologic data were collected, and immunohistochemistry for p16 and p21 was performed and interpreted by 3 independent pathologists.

Complete clinical remission of malignant peritoneal mesothelioma with systemic pemetrexed and bevacizumab in a patient with a BAP1 mutation.

Malignant peritoneal mesothelioma (MPeM) is a rare malignancy with historically poor prognosis. Recent research has started to reveal increasingly prevalent genetic mutations seen in this malignancy. Here, we report a case of complete clinical remission of unresectable, metastatic MPeM with systemic chemotherapy.

Gene partners of the EWSR1 fusion may represent molecularly distinct entities.

EWSR1 fusions are highly promiscuous and are associated with unique malignancies, clinical phenotypes, and molecular subtypes. However, rare fusion partners (RFP) of EWSR1 has not been well described. Here, we conducted a cross-sectional, retrospective study of 1,140 unique tumors harboring EWSR1 fusions.

TYMS promotes genomic instability and tumor progression in Ink4a/Arf null background.

We previously showed that elevated TYMS exhibits oncogenic properties and promotes tumorigenesis after a long latency, suggesting cooperation with sequential somatic mutations. Here we report the cooperation of ectopic expression of human TYMS with loss of Ink4a/Arf, one of the most commonly mutated somatic events in human cancer. Using an hTS/Ink4a/Arf genetically engineered mouse model we showed that deregulated TYMS expression in Ink4a/Arf null background accelerates tumorigenesis and metastasis.

First-in-class multifunctional TYMS nonclassical antifolate inhibitor with potent in vivo activity that prolongs survival.

Although thymidylate synthase (TYMS) inhibitors have served as components of chemotherapy regimens, the currently available inhibitors induce TYMS overexpression or alter folate transport/metabolism feedback pathways that tumor cells exploit for drug resistance, limiting overall benefit. Here we report a small molecule TYMS inhibitor that i) exhibited enhanced antitumor activity as compared with current fluoropyrimidines and antifolates without inducing TYMS overexpression, ii) is structurally distinct from classical antifolates, iii) extended survival in both pancreatic xenograft tumor models and an hTS/Ink4a/Arf null genetically engineered mouse tumor model, and iv) is well tolerated with equal efficacy using either intraperitoneal or oral administration. Mechanistically, we verify the compound is a multifunctional nonclassical antifolate, and using a series of analogs, we identify structural features allowing direct TYMS inhibition while maintaining the ability to inhibit dihydrofolate reductase.

Aneurysmal bone cyst: a review.

Aneurysmal bone cyst (ABC) is a benign locally destructive bone neoplasm composed of multi-loculated blood-filled cystic spaces. The most common sites of involvement are the meta-diaphysis of the long bones and posterior elements of the vertebrae. Secondary, ABC-like changes can complicate a variety of other benign and malignant primary bone neoplasms, including giant cell tumor, fibrous dysplasia, and osteosarcoma.

Myofibroma mimicking peripheral nerve sheath tumour with ulnar nerve compression symptoms.

We report a case of myofibroma encasing the ulnar nerve on the medial aspect of the left arm with motor and sensory deficit secondary to compression. Initially, the tumour appeared to be a benign peripheral nerve sheath tumour based on preoperative imaging, with clinical examination positive for left hand clawing and a positive Wartenberg's and Froment's sign. However, intraoperative dissection demonstrated that the mass did not originate from the ulnar nerve proper, lowering suspicion for a peripheral nerve sheath tumour.

Metastatic malignant peripheral nerve sheath tumour in a patient with neurofibromatosis 1 and review of contemporary systemic treatments.

Malignant peripheral nerve sheath tumours are rare soft tissue sarcomas commonly seen in patients with neurofibromatosis type 1. They typically manifest in the fibrous sheaths of major nerve trunks in the extremities or in an axial location. Presenting symptoms are generally non-specific, including pain and weakness, and survival is dependent on size and location of the tumour.

Arthroscopic treatment for intra-articular fibroma of the tendon sheath in a teenager.

An adolescent female patient presented with atraumatic left knee pain and limited flexion. MRI demonstrated evidence of a soft tissue lesion abutting the posterior cruciate ligament. Differential diagnosis included pigmented villonodular synovitis (PVNS) and fibroma of the tendon sheath (FTS).

Complex Reconstruction for Acetabular Pathologic Fracture in Unusual Chondroblastoma With Aneurysmal Bone Cyst.

Treating bone loss with complex arthroplasty poses a significant challenge for the arthroplasty surgeon. When considering a reconstructive case after pathologic fracture and oncologic excision, a multidisciplinary approach with reliance on arthroplasty principles is critical. An 18-year-old patient presented with a complex acetabular pathologic fracture through a chondroblastoma with a secondary aneurysmal bone cyst.

Leiomyosarcoma of the Nasal Cavity and Paranasal Sinuses: A Case Report and Comprehensive Review of the Literature.

Sinonasal leiomyosarcoma (LMS) is a rare and aggressive mesenchymal tumor with smooth muscle differentiation. The sinonasal tract is an unusual primary site for LMS, as scant smooth muscle exists in this location, with only 75 cases reported in the English literature including the case presented herein. Sinonasal LMS is considered an aggressive head and neck tumor with significant potential for recurrence and metastasis.

Gene Therapy for Osteoarthritis: Pharmacokinetics of Intra-Articular Self-Complementary Adeno-Associated Virus Interleukin-1 Receptor Antagonist Delivery in an Equine Model.

Toward the treatment of osteoarthritis (OA), the authors have been investigating self-complementary adeno-associated virus (scAAV) for intra-articular delivery of therapeutic gene products. As OA frequently affects weight-bearing joints, pharmacokinetic studies of scAAV gene delivery were performed in the joints of the equine forelimb to identify parameters relevant to clinical translation in humans. Using interleukin-1 receptor antagonist (IL-1Ra) as a secreted therapeutic reporter, scAAV vector plasmids containing codon-optimized cDNA for equine IL-1Ra (eqIL-1Ra) were generated, which produced eqIL-1Ra at levels 30- to 50-fold higher than the native sequence.

Self-Complementary Adeno-Associated Virus-Mediated Interleukin-1 Receptor Antagonist Gene Delivery for the Treatment of Osteoarthritis: Test of Efficacy in an Equine Model.

The authors are investigating self-complementary adeno-associated virus (scAAV) as a vector for intra-articular gene-delivery of interleukin-1 receptor antagonist (IL-1Ra), and its therapeutic capacity in the treatment of osteoarthritis (OA). To model gene transfer on a scale proportional to the human knee, a frequent site of OA incidence, studies were focused on the joints of the equine forelimb. Using AAV2.

Eps8 expression is significantly lower in p16 head and neck squamous cell carcinomas (HNSCCs) compared with p16 HNSCCs.

In vitro head and neck cancer studies have demonstrated that epidermal growth factor receptor kinase substrate 8 (Eps8) overexpression contributes to squamous carcinogenesis. Oral squamous cell carcinoma studies have correlated Eps8 expression with metastatic disease and poor prognosis. Head and neck squamous cell carcinoma (HNSCC) studies comparing its expression by anatomic site or in in vivo regional metastases have not been performed.