Metastatic chondroblastoma with elevated creatine kinase and paraneoplastic neurologic autoimmunity

Comprehensive Insights into Chondroblastoma Metastasis: Metastatic Patterns and Therapeutic Approaches

Chondroblastoma metastasis, though rare, represents a clinically significant and notably important aspect of bone tumors. Understanding its epidemiological characteristics, pathological features, and treatment modalities, despite its infrequency, is imperative for comprehensive patient management. This review aims to elucidate the epidemiology, molecular mechanisms, diagnostic challenges, and therapeutic strategies associated with chondroblastoma metastasis. The patterns, prognostic factors, and treatment outcomes were explored through an analysis of case studies and clinical reports. Notably, we highlighted emerging therapeutic perspectives aimed at improving patient outcomes. To the best of our knowledge, there has been no previous review addressing these matters cumulatively, highlighting a significant gap in the existing scholarly literature. By shedding light on the nuances of chondroblastoma metastasis, this review contributes to the advancement of knowledge in this field and informs clinical decision-making for improved patient care.

What's New in Pediatric Orthopaedic Tumor Surgery

BACKGROUND

Pediatric Orthopaedic Oncology is a developing subspecialty within the field of Pediatric Orthopaedics. Traditionally, the field of Orthopaedic Oncology has been focused on the skeletally mature individual, and the research tends to be all encompassing rather than truly evaluating isolated populations. The purpose of this review is to summarize the most clinically relevant literature in the field of Pediatric Orthopaedic Oncology over the last 6 years.

METHODS

We evaluated the PubMed database utilizing keywords for pediatric orthopaedic oncology: sarcoma, osteosarcoma, Ewing sarcoma, bone cyst. In additionally, we further broadened our search by searching for relevant articles in the contents sections of major orthopaedic surgery journals that routinely publish both pediatric and orthopaedic oncology literature. In keeping with "What's New," we selected the most clinically relevant articles published in the last 6 years from January 1, 2014 through February 2020. Basic science and systemic therapies literature was widely reviewed and the research and clinical trials most relevant to pediatric sarcoma and neoplastic processes found in the pediatric population were included.

RESULTS

Our search yielded 60 articles that met general criteria, from which 14 were determined to be most relevant to the goals of this paper. Of the papers presented in this review, there were papers related to management of benign tumors/tumor-like conditions, bone cysts, limb salvage procedures, and amputation procedures. Ultimately included in the review were 5 studies related to limb salvage, 4 related to bone cysts, 1 related to multiple hereditary exostoses, 2 related to osteofibrous dysplasia, 1 related to chondroblastoma, and 1 discussing cementation in skeletally immature patients. They were level III, IV, and V studies. Basic science and systemic therapies literature was widely reviewed and the research and clinical trials most relevant to pediatric sarcoma and neoplastic processes found in the pediatric population were included. Our search of the basic science and systemic therapies literature yielded 19 sources were found to be pertinent to our aims and 18 of those sources were published between 2015 and 2020.

CONCLUSIONS

There are many, varied, and creative procedures in the realm of limb salvage, though there remains a lack of high-level evidence to support some of the more novel procedures. In regards to benign bone tumors, despite a more solid base of literature, there still does not seem to be consensus as to the best treatment. In particular, there continue to be many schools of thought on the treatment of benign bone cysts. Research in the basic science arena and systemic therapies are advancing in exciting ways in regards to pediatric sarcoma. Orthopaedic oncologic research specific to the pediatric population overall continues to be impeded by low sample sizes and inadequate levels of evidence, which limits the ability of surgeons to draw definitive conclusions from the literature.

The role of the laboratory in the expanding field of neuroimmunology: Autoantibodies to neural targets

Accelerated identification of autoantibodies associated with previously idiopathic neurological disease has provided insights into disease mechanisms, enhanced understanding of neurological function, and opportunities for improved therapeutic interventions. The role of the laboratory in the expanding field of neuroimmunology is critical as specific autoantibody identification provides guidance to clinicians in diagnosis, prognosis, tumor search strategies, and therapeutic interventions. The number of specific autoantibodies identified continues to increase and newer testing strategies increase efficiencies in the laboratory and availability to clinicians. The need for broadly targeted efficient testing is underscored by the variability in clinical presentation and tumor associations attributable to a specific autoantibody, and conversely the various autoantibody specificities that can be the cause of a given clinical presentation. While many of the antineural antibodies were first recognized in the setting of neoplastic disease, idiopathic autoimmune neurological disease in the absence of underlying tumor is increasingly recognized. Appropriation of therapeutic modalities used to treat autoimmune disease to treat these autoantibody mediated neurological diseases has improved patient outcomes. Interaction between clinicians and laboratorians is critical to our understanding of these diseases and optimization of the clinical benefits of our increasing knowledge in neuroimmunology.

Double trouble: para-neoplastic anti-PCA-2 and CRMP-5-mediated small fibre neuropathy followed by chorea associated with small cell lung cancer and evolving radiological features

Patients with Purkinje cell cytoplasmic autoantibody type 2 (PCA-2) and collapsin response-mediator protein-5 (CRMP-5) autoantibody can present with multifocal elements of encephalomyeloneuropathy. Except for an anecdotal report, case descriptions of paraneoplastic small fibre neuropathy are lacking. We report paraneoplastic small fibre neuropathy followed by chorea associated with small cell lung cancer. A man aged 57 years with a 35 pack-year smoking history presented with painless subacute paresthesia and weight fluctuation. A non-length-dependent small fibre neuropathy was confirmed by skin biopsy. Further testing revealed positive serum PCA-2 and CRMP-5 autoantibodies, which after positron emission tomography-CT led to histological confirmation of a small cell lung cancer. Initially, abnormal MRI and cerebrospinal fluid studies suggested central nervous system (CNS) involvement which was subclinical; however, 6 months later during antitumour therapy, the patient became symptomatic with choreoathetosis. After combined chemoradiation as well as immunosuppressive and symptomatic therapies, the clinical course stabilised, although residual neurological deficits remained at follow-up a year later. Coexistent PCA-2 and CRMP-5 autoantibodies may occur in the setting of small fibre peripheral neuropathy and choreoathetosis and predict cancer type. Two paraneoplastic syndromes can present successively over months; subclinical CNS involvement with evolving basal ganglia abnormalities can be a paraneoplastic manifestation. In the appropriate clinical setting, paraneoplastic testing should be considered in patients presenting with small fibre neuropathy.

Chondroblastoma and chondromyxoid fibroma

Chondroblastoma and chondromyxoid fibroma are benign but locally aggressive bone tumors. Chondroblastoma, a destructive lesion with a thin radiodense border, is usually seen in the epiphysis of long bones. Chondromyxoid fibroma presents as a bigger, lucent, loculated lesion with a sharp sclerotic margin in the metaphysis of long bones. Although uncommon, these tumors can be challenging to manage. They share similarities in pathology that could be related to their histogenic similarity. Very rarely, chondroblastoma may lead to lung metastases; however, the mechanism is not well understood.

Neuronal voltage-gated potassium channel complex autoimmunity in children

Autoimmunity targeting voltage-gated potassium channel complexes have not been systematically documented in children. Identified in the Neuroimmunology Laboratory records of Mayo Clinic were 12 seropositive children, 7 among 252 Mayo Clinic pediatric patients tested on a service basis for serologic evidence of neurologic autoimmunity (June 2008-April 2010), 4 during the assay's preimplementation validation (before June 2008) and 1 non-Mayo patient with available clinical information. Neurologic manifestations were subacute and multifocal. Three had global developmental regression, 6 movement disorders, 4 dysarthria, 3 seizures, 1 Satoyoshi syndrome, 1 painful red feet, 2 insomnia, 2 gastrointestinal dysmotility, and 2 small fiber neuropathy. Neoplasia was found in 1 child. Treating physicians recorded improvement in all 7 children who received immunotherapy. Neurologic symptom relapse occurred in 3 of 6 children after ceasing immunotherapy. These findings highlight a diverse clinical spectrum of neuronal potassium channel complex autoimmunity in children, and they illustrate benefit from early initiated immunotherapy, with a tendency to relapse when therapy ceases. Diagnosis is generally delayed in the process of eliminating neurodegenerative causes. Currently 2.7% of pediatric sera evaluated for neurologic autoimmunity are positive for neuronal potassium channel complex-reactive immunoglobulin G. The frequency and full spectrum of neurologic accompaniments remains to be determined.

Giant chondroblastoma of the scapula with pulmonary metastases

A 53-year-old man presented with a 12-year history of a progressively growing solid mass at his left shoulder. A 39x30x18-cm and 14.440-kg mass including the scapula was resected. Pathologic features were specific for chondroblastoma. During the 36-month follow-up, he had multiple inoperable metastatic lesions in his lungs. Histology of the transthoracic needle biopsy showed the metastatic nodules had features specific for chondroblastoma; however, the microscopic features additionally had hyperchromasia and increased mitotic activity in some areas. In the English literature, there are a few cases of chondroblastoma located in the scapula. It is exceptional to see this lesion in the sixth decade of life and with pulmonary metastases.

Early signals for fracture healing

Fracture healing requires the cooperation of multiple molecular signaling pathways. To better understand this cascade of transcriptional events, we compared the gene expression profiles between intact bone and fractured bone at days 1, 2, and 4 using a rat femur model of bone healing. Cluster analysis identified several groups of genes with dynamic temporal expression patterns and stage-specific functions. The immediate-response genes are highlighted by binding activity, transporter activity, and energy derivation. We consider these activities as critical signals for initiation of fracture healing. The continuously increased genes are characterized by those directly involved in bone repair, thus, representing bone specific forefront workers. The constantly upregulated genes tend to regulate general cell growth and are enriched with genes that are involved in tumorigenesis, suggesting common pathways between two processes. The constantly downregulated genes predominantly involve immune response, the significance of which remains for further investigation. Knowledge acquired through this analysis of transcriptional activities at the early stage of bone healing will contribute to our understanding of fracture repair and bone-related pathological conditions.