Light-chain Deposition Diseases of the CNS: Review of Pathogenesis, Imaging Features and Radiographic Mimics.

Light-chain deposition disease (LCDD) is a rare CNS disorder characterized by the extracellular accumulation of monoclonal immunoglobulin light chains in various organs. LCDD typically arises secondary to an underlying plasma cell dyscrasia, such as monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma. However, rare cases can occur in the absence of a demonstrable plasma cell disorder. The kidneys, liver, lungs, and heart are the most affected organs. Intracerebral LCDD, particularly without an underlying plasma cell neoplasm, represents an exceedingly uncommon entity with limited documented cases in literature. This review article explores the pathogenesis, histopathological features, and characteristic neuroimaging findings of intracerebral LCDD. We emphasize the diverse imaging presentations of this disease, which can closely resemble other neurological pathologies. Recognizing these potential mimics is crucial for avoiding misdiagnosis, especially in the absence of a known underlying plasma cell disorder. This article aims to provide a comprehensive overview from a neuroradiological perspective, facilitating the recognition and differentiation of this challenging entity.ABBREVIATIONS: LCDD, light chain deposition disease; ALD, amyloidoma.

Imaging Guide to Inner Ear Malformations: An Illustrative Review.

Inner ear malformation (IEM) with associated sensoryneural hearing loss (SNHL) is a major cause of childhood disability. Computed tomography (CT) and magnetic resonance imaging (MRI) imaging play important and often complementary roles in diagnosing underlying structural abnormalities and surgical planning allows for direct visualization of the cochlear nerve and is the preferred imaging modality prior to cochlear implantation. CT is helpful to assess osseous anatomy and when evaluating children with mixed hearing loss or syndromic associations. When reviewing these cases, it is important for the radiologist to be familiar with the key imaging features. In this article, we will present the imaging findings associated with different inner ear malformations associated with congenital sensorineural hearing loss.

Primary Paraganglioma of the Spine: A Systematic Review of Clinical Features and Surgical Management in Cauda Equina versus Non-Cauda Equina Lesions.

BACKGROUND: Primary spine paragangliomas are rare tumors. Surgical resection plays a role, but aggressive lesions are challenging. We reviewed the literature on primary spine paragangliomas. METHODS: PubMed, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies on primary spine paragangliomas. Clinical-radiologic features, treatments, and outcomes were analyzed and compared between cauda equina versus non-cauda equina tumors. RESULTS: We included 143 studies comprising 334 patients. Median age was 46 years (range, 6-85 years). The most frequent symptoms were lower back (64.1%) and radicular (53.9%) pain, and sympathetic in 18 patients (5.4%). Cauda equina paragangliomas (84.1%) had frequently lumbar (49.1%) or lumbosacral (29%) locations. Non-cauda equina tumors were mostly in the thoracic (11.4%), thoracolumbar (5.1%), and cervical (3.6%) spine. Median tumor diameter was 2.5 cm (range, 0.5-13.0 cm). Surgical resection (98.5%) was preferred over biopsy (1.5%). Decompressive laminectomy (53%) and spine fusion (6.9%) were also performed. Adjuvant radiotherapy was delivered in 39 patients (11.7%) with aggressive tumors. Posttreatment symptomatic improvement was described in 86.2% cases. Median follow-up was 19.5 months (range, 0.1-468.0 months), and 23 patients (3.9%) had tumor recurrences. No significant differences were found between cauda equina versus non-cauda equina tumors. CONCLUSIONS: Surgical resection is effective and safe in treating primary spine paragangliomas; however, adjuvant treatments may be needed for aggressive lesions.

Brain on fire: an imaging-based review of autoimmune encephalitis.

Autoimmune encephalitis represents an increasingly recognized group of immune-mediated disorders the affect the central nervous system. The purpose of this article is to highlight the characteristic MR imaging findings associated with autoimmune encephalitis, describe the pathophysiology, review antibodies that have been identified and their patterns of CNS involvement, and discuss approaches to management. Familiarity with the imaging and clinical features of autoimmune encephalitis will prompt the radiologist to suggest the diagnosis which can facilitate appropriate management.

External Ear Diseases: A Comprehensive Review of the Pathologies With Neuroradiological Considerations.

The peripheral auditory system is subdivided into 3 compartments: the external, middle, and inner ear. Historically, the middle and inner ear have garnered more attention in the imaging literature, due to their intricate anatomy and complexity of pathologies. The external ear, however, has attained less recognition given its relatively straightforward anatomy and convenience of direct visual examination. The continued advancement in computed tomography and magnetic resonance imaging has expanded the role of radiology in the evaluation of the external ear lesions. The purpose of this article is to offer a comprehensive review of external ear pathologies, including congenital, inflammatory, infectious, traumatic, neoplastic, and rare disease entities and their imaging findings.

Percutaneous image-guided cryoablation of spinal metastases: A systematic review.

Percutaneous cryoablation (PCA) is a minimally invasive technique that has been recently used to treat spinal metastases with a paucity of data currently available in the literature. A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Prospective or retrospective studies concerning metastatic spinal neoplasms treated with current generation PCA systems and with available data on safety and clinical outcomes were included. In the 8 included studies (7 retrospective, 1 prospective), a total of 148 patients (females = 63%) underwent spinal PCA. Tumors were located in the cervical (3/109 [2.8%], thoracic (74/109 [68.8%], lumbar (37/109 [33.9%], and sacrococcygeal (17/109 [15.6%] regions. Overall, 187 metastatic spinal lesions were treated. Thermo-protective measures (e.g., carbo-/hydro-dissection, thermocouples) were used in 115/187 [61.5%] procedures. For metastatic spinal tumors, the pooled mean difference (MD) in pain scores from baseline on the 0-10 numeric rating scale was 5.03 (95% confidence interval [CI]: 4.24 to 5.82) at a 1-month follow-up and 4.61 (95% CI: 3.27 to 5.95) at the last reported follow-up (range 24-40 weeks in 3/4 studies). Local tumor control rates ranged widely from 60% to 100% at varying follow-ups. Grade I-II complications were reported in 9/148 [6.1%] patients and grade III-V complications were reported in 3/148 [2.0%]) patients. PCA, as a stand-alone or adjunct modality, may be a viable therapy in appropriately selected patients with painful spinal metastases who were traditionally managed with open surgery and/or radiation therapy.

Alterations in the RB Pathway With Inactivation of RB1 Characterize Glioblastomas With a Primitive Neuronal Component.

A primitive neuronal component is a feature of some glioblastomas but defining molecular alterations of this histologic variant remains uncertain. We performed next-generation sequencing of 1500 tumor related genes on tissue from 9 patients with glioblastoma with a primitive component (G/PN) and analyzed 27 similar cases from the Cancer Genome Atlas (TCGA) dataset. Alterations in the RB pathway were identified in all of our patients' tumors and 81% of TCGA tumors with the retinoblastoma tumor suppressor gene (RB1) commonly affected. Although RB1 mutations were observed in some conventional glioblastomas, the allelic fractions of these mutations were significantly higher in tumors with a primitive neuronal component in both our and TCGA cohorts (median, 72% vs 25%, p < 0.001 and 80% vs 40%, p < 0.02, respectively). Further, in 78% of patients in our cohort, RB expression was lost by immunohistochemistry. Our findings indicate that alterations in the RB pathway are common in G/PNs and suggest that inactivation of RB1 may be a driving mechanism for the phenotype.

Fundamentals of Radiation Oncology for Treatment of Vertebral Metastases.

The fields of both radiology and radiation oncology have evolved considerably in the past few decades, resulting in an increased ability to delineate between tumor and normal tissue to precisely target and treat vertebral metastases with radiation therapy. These scientific advances have also led to improvements in assessing treatment response and diagnosing toxic effects related to radiation treatment. However, despite technological innovations yielding greatly improved rates of palliative relief and local control of osseous spinal metastases, radiation therapy can still lead to a number of acute and delayed posttreatment complications. Treatment-related adverse effects may include pain flare, esophageal toxic effects, dermatitis, vertebral compression fracture, radiation myelopathy, and myositis, among others. The authors provide an overview of the multidisciplinary approach to the treatment of spinal metastases, indications for surgical management versus radiation therapy, various radiation technologies and techniques (along with their applications for spinal metastases), and current principles of treatment planning for conventional and stereotactic radiation treatment. Different radiologic criteria for assessment of treatment response, recent advances in radiologic imaging, and both common and rare complications related to spinal irradiation are also discussed, along with the imaging characteristics of various adverse effects. Familiarity with these topics will not only assist the diagnostic radiologist in assessing treatment response and diagnosing treatment-related complications but will also allow more effective collaboration between diagnostic radiologists and radiation oncologists to guide management decisions and ensure high-quality patient care. ©RSNA, 2021.

Is there a doctor on the plane? A review of in-flight emergencies for the on-board radiologist.

In-flight medical emergencies (IFME) are the acute on-service events involving illness or injury to a passenger with the potential for long-term health compromise. With the continuously rising number of flights available, both domestically and internationally, it is conceivable that the number of IFMEs will similarly continue to rise. Although most of these instances are relatively self-limited, the rare instance of a severe occurrence justifies preparation, both from in-flight staff and healthcare providers traveling on these flights. Given these events' sporadic nature and the variable availability of medical support, all physicians need to understand their in-flight ethical and legal capabilities, the available medical supplies, and the most likely etiologies to manage such situations successfully. Most radiologists rarely utilize the hands-on, clinical skills developed in medical school or internship for emergencies beyond allergic contrast reactions. Therefore, they may not be adept in caring for patients during an IFME. As such, we present a thorough overview and literature review for the radiologist regarding the management of various acute IFMEs, with consideration for ethical and legal precedence and a review of medical equipment available on-board.

Uremic Leontiasis Ossea.

While renal osteodystrophy is a common complication of chronic renal failure which is caused by secondary hyperparathyroidism, it is rare that the bony changes result in a severe progressive overgrowth of the bones of the face such that the patient is at risk for breathing and feeding difficulties. When this occurs, it is called uremic leontiasis ossea and patients who suffer from this rare, severe complication of renal osteodystrophy may go undiagnosed or be misdiagnosed resulting improper management due to its limited discussion in the literature. We report a case of a 42-year-old man with end-stage renal disease who was unable to receive dialysis consistently for many years who was found to have a large hard mass on the palate and palate ulcers.

Motivation: how to create a cohort of engaged, energized, and happy radiology trainees.

Burnout among physicians continues to be a "hot topic" as medical culture struggles to adapt to the changing marketplace, where clinical demands are ever increasing but healthcare systems are pivoting to prefer value and cost-savings. To date, many attempts to understand and battle burnout center around the individual physician, rather than the system, limiting the medical community's ability to counter it successfully. The training environment is a common nidus for burnout. By promoting an understanding of motivation, happiness, and engagement in the workplace, we suggest several changes that training programs can make to minimize burnout and promote resident wellness. Creating a culture of support, promoting a positive work environment, building a cohesive team, and encouraging wellness both inside and outside the workplace stands to create engaged, happy, and motivated trainees who will hopefully continue to promote those strategies as they advance their careers.

Neurological emergencies associated with COVID-19: stroke and beyond.

Novel coronavirus disease (COVID-19) was declared a global pandemic on March 1, 2020. Neurological manifestations are now being reported worldwide, including emergent presentation with acute neurological changes as well as a comorbidity in hospitalized patients. There is limited knowledge on the neurologic manifestations of COVID-19 at present, with a wide array of neurological complications reported, ranging from ischemic stroke to acute demyelination and encephalitis. We report five cases of COVID-19 presenting to the ER with acute neurological symptoms, over the course of 1 month. This includes two cases of ischemic stroke, one with large-vessel occlusion and one with embolic infarcts. The remainders of the cases include acute tumefactive demyelination, isolated cytotoxic edema of the corpus callosum with subarachnoid hemorrhage, and posterior reversible encephalopathy syndrome (PRES).

Fundamentals of Radiation Oncology for Neurologic Imaging.

Although the physical and biologic principles of radiation therapy have remained relatively unchanged, a technologic renaissance has led to continuous and ever-changing growth in the field of radiation oncology. As a result, medical devices, techniques, and indications have changed considerably during the past 20-30 years. For example, advances in CT and MRI have revolutionized the treatment planning process for a variety of central nervous system diseases, including primary and metastatic tumors, vascular malformations, and inflammatory diseases. The resultant improved ability to delineate normal from abnormal tissue has enabled radiation oncologists to achieve more precise targeting and helped to mitigate treatment-related complications. Nevertheless, posttreatment complications still occur and can pose a diagnostic challenge for radiologists. These complications can be divided into acute, early-delayed, and late-delayed complications on the basis of the time that they manifest after radiation therapy and include leukoencephalopathy, vascular complications, and secondary neoplasms. The different irradiation technologies and applications of these technologies in the brain, current concepts used in treatment planning, and essential roles of the radiation oncologist in the setting of brain disease are reviewed. In addition, relevant imaging findings that can be used to delineate the extent of disease before treatment, and the expected posttreatment imaging changes are described. Common and uncommon complications related to radiation therapy and the associated imaging manifestations also are discussed. Familiarity with these entities may aid the radiologist in making the diagnosis and help guide appropriate management. ©RSNA, 2020.

Intramedullary Neurocysticercosis Mimicking Cord Tumor.

Isolated spinal intramedullary involvement by neurocysticercosis is extremely rare. We report a case of a Hispanic female with right-sided weakness, magnetic resonance imaging showing cervical intramedullary lesion. Surgery was performed due to the progressive nature of symptoms. The cervical cord lesion was completely removed; pathology was consistent with degenerated cysticercosis. Progressive clinical improvement with physiotherapy was achieved. Although rare, especially in the absence of intracranial lesions, the diagnosis should be considered in appropriate patient population as it usually presents a peripherally enhancing cystic lesion.

Primary and Secondary Breast Lymphoma: Clinical, Pathologic, and Multimodality Imaging Review.

Breast lymphoma is a rare hematologic neoplasm that originates in the breast lymphoid tissue and includes primary breast lymphoma (PBL) and secondary breast lymphoma (SBL). PBL involves the breast lymphoid tissue in the absence of previously identified extramammary lymphoma and widespread disease. SBL is the most common metastasis to the breast, accounting for 17% of metastatic disease to the breast. PBL and SBL usually demonstrate imaging phenotypes that overlap with those of primary breast carcinoma, which makes a prospective diagnosis of breast lymphoma challenging. These nonspecific imaging features include an iso- to hyperdense oval mass or masses at mammography, a hypoechoic or mixed-echogenicity hypervascular mass at US, an enhancing mass with type II kinetics at MRI, and high fluorine 18-fluorodeoxyglucose avidity at PET. In cases of suspected lymphoma, reviewing the clinical history, using appropriate biopsy techniques, and evaluating for multiplicity, bilaterality, and distant disease are critical for diagnosis and management. A patient with PBL generally has an earlier clinical presentation with a palpable abnormality and a solitary imaging finding. In contrast, multiple masses in an older patient and an occult clinical presentation favor an SBL diagnosis. ©RSNA, 2019.

Ibrutinib Use Complicated by Progressive Multifocal Leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease associated with immunocompromised states. We describe a case of PML, which developed after prolonged ibrutinib use and a low burden of chronic lymphocytic leukemia disease. The delay in diagnosis of the patient despite multiple presentations to medical providers across different facilities suggests that there is a lack of awareness of PML as a potential complication of ibrutinib. Treatments with postulated anti-John Cunningham polyomavirus agents and IL-2 were ineffective, likely due to the advanced state of the patient's disease. Although recent evidence indicates that ibrutinib may enhance cell-mediated immunity, consistent with elevated CD4+ and CD8+ T cells and appropriate T-cell response to mitogens in the patient, ibrutinib-mediated inhibition of the humoral function may contribute to PML pathogenesis. As the duration of ibrutinib use is often indefinite, and the number of indications for ibrutinib continues to grow, recognition and further evaluation of the link between PML and ibrutinib is warranted.

Spindle cell lesions of the breast: Multimodality imaging and clinical differentiation of pathologically similar neoplasms.

Spindle cell lesions of the breast comprise a wide-range of entities including reactive, benign and malignant proliferations. They can be pathologically challenging to differentiate as there is often immunohistochemical and morphologic similarities with characteristic spindle shaped cellular patterns. Radiological and pathological correlation is essential. Radiology detects, defines the size and extent, and assists in localizing the lesions. Pathology confirms the diagnosis and provides prognostic parameters. Familiarity with the clinicoradiological features of these diagnostically challenging lesions helps to establish an accurate pathological diagnosis and subsequent clinical decision making.

Breast metastasis in an adult woman with alveolar rhabdomyosarcoma of the ethmoid sinus.

A new breast mass was identified in an adult woman undergoing treatment for a known ethmoid sinus alveolar rhabdomyosarcoma. Histopathological evaluation revealed alveolar rhabdomyosarcoma metastatic to the breast. Alveolar rhabdomyosarcoma, primarily described in adolescents and especially rare in adults, can uncommonly metastasize to the breast.