What MRI can tell us about neurogenic tumors and rhabdomyosarcoma

Relationship between magnetic resonance imaging findings and histological grade in spinal peripheral nerve sheath tumors in dogs

BACKGROUND

Peripheral nerve sheath tumors (PNSTs) are a group of neoplasms originating from Schwann cells or pluripotent cell of the neural crest. Therapeutic options and prognosis are influenced by their degree of malignancy and location.

HYPOTHESIS/OBJECTIVES

Identify magnetic resonance imaging (MRI) features predictive of PNST histologic grade.

ANIMALS

Forty-four dogs with histopathological diagnosis of spinal PNSTs and previous MRI investigation.

METHODS

A multicenter retrospective study including cases with (a) histopathologic diagnosis of PNST and (b) MRI studies available for review. Histologic slides were reviewed and graded by a board-certified pathologist according to a modified French system (FNCLCC) for grading soft tissue sarcomas. The MRI studies were reviewed by 2 board-certified radiologists blinded to the grade of the tumor and the final decision on the imaging characteristics was reached by consensus. Relationships between tumor grade and histological and MRI findings were assessed using statistical analysis.

RESULTS

Forty-four cases met inclusion criteria; 16 patients were PNSTs Grade 1 (low-grade), 19 were PNSTs Grade 2 (medium-grade), and 9 were PNSTs Grade 3 (high-grade). Large volume (P = .03) and severe peripheral contrast enhancement (P = .04) were significantly associated with high tumor grade. Degree of muscle atrophy, heterogeneous signal and tumor growth into the vertebral canal were not associated with grade.

CONCLUSIONS AND CLINICAL IMPORTANCE

Grade of malignancy was difficult to identify based on diagnostic imaging alone. However, some MRI features were predictive of high-grade PNSTs including tumor size and peripheral contrast enhancement.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 2: vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5^th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous organ soft tissues, as well as the peripheral and autonomic nervous system.

Mind–Body Exercises for Non-motor Symptoms of Patients With Parkinson’s Disease: A Systematic Review and Meta-Analysis

Objective: This study aimed to systematically evaluate the effects of mind–body exercise on global cognitive function, depression, sleep disorders, fatigue level, and quality of life (QOL) in a Parkinson’s disease (PD) population.

Methods: Total six English and Chinese databases were searched for articles published up to May 2021. Randomized controlled trials (RCTs) evaluating mind–body excises on non-motor symptoms of PD were included. The Cochrane risk of bias tool was used to assess the methodological quality, and we defined high-quality studies as having a low risk of bias in four or more domains. Global cognitive function was considered the primary outcome and was assessed using the Montreal Cognitive Assessment (MoCA). The secondary outcomes included QOL, fatigue, depression, and sleep quality, which were measured using the Parkinson’s Disease Questionnaire (PDQ-39), 16-item Parkinson’s Disease Fatigue Scale (PFS-16), Beck Depression Inventory (BDI), and revised Parkinson’s Disease Sleep Scale (PDSS-2), respectively. Subgroup analyses were conducted for global cognitive function and QOL to assess the optimal treatment measure across the various mind–body exercises.

Results: Fourteen RCTs with 404 patients were finally included in the meta-analysis. Eight (57.14%) studies were of high quality. The pooled results showed that mind–body exercises generally had a significant advantage over the control intervention in improving global cognitive function (MD = 1.68; P = 0.0008). The dose subgroup analysis revealed that the low dose (60–120 min per week) and moderate dose (120–200 min per week) significantly increased MoCA scores compared with the control group (MD = 2.11, P = 0.01; MD = 1.27, P = 0.02, respectively). The duration subgroup analysis indicated a significant difference in the effect of the duration (6–10 and >15 weeks) on increasing MoCA scores compared with the control group (MD = 3.74, P < 0.00001; MD = 1.45, P = 0.01, respectively).

Conclusion: Mind–body exercise may improve global cognitive function, sleep quality, and QOL in the PD population. In addition, low to moderate doses and appropriate durations significantly improved global cognitive function.

Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [CRD42021275522].

Radiologic-Pathologic Correlation of Primary Retroperitoneal Neoplasms

An earlier incorrect version of this article appeared in print. The online version is correct.

Pearls and Pitfalls in the Imaging of Soft-Tissue Masses in Children

There is a broad spectrum of soft-tissue masses in children that can be challenging to diagnose clinically and on imaging. This article reviews the typical clinical and imaging findings of the most common and relevant benign, intermediate and malignant pediatric soft-tissue tumors in the following categories of the 2013 World Health Organization (WHO) classification: adipocytic tumors (lipoma, lipoblastoma, and liposarcoma), fibroblastic/myofibroblastic tumors (nodular fasciitis, myositis ossificans, fibrous hamartoma of infancy, fibromatosis colli, desmoid-type fibromatosis, lipofibromatosis, and infantile fibrosarcoma), pericytic tumors (myofibroma/myofibromatosis), skeletal muscle tumor (rhabdomyosarcoma), nerve sheath tumors (neurofibroma, malignant peripheral nerve sheath tumor), and uncertain differentiation (synovial sarcoma). In general, ultrasound and magnetic resonance imaging are used as first- and second-line imaging modalities, with limited roles for plain radiographs, computed tomography, and fluorodeoxyglucose-positron emission tomography. Many of these tumors have nonspecific imaging findings although there are some key imaging clues that in conjunction with the clinical information allow a specific diagnosis or a narrow differential diagnosis. However, in many instances, histology is required for final diagnosis.

Overview of the clinical and imaging features of the most common non-rhabdomyosarcoma soft-tissue sarcomas

Non-rhabdomyosarcoma soft-tissue sarcoma (NRSTS) refers to a widely heterogeneous group of extraskeletal mesenchymal neoplasms accounting for approximately 4% of all childhood cancers. This article summarizes the clinical and imaging features of these rare tumors and describes in detail the three most common histological types of NRSTSs encountered in children - synovial sarcoma, malignant peripheral nerve sheath tumor and infantile fibrosarcoma. The author discusses the role of non-cross-sectional and cross-sectional imaging.

Magnetic resonance neurography appearance and diagnostic evaluation of peripheral nerve sheath tumors

Imaging appearances of peripheral nerve sheath tumors by MRI are difficult distinguish from soft-tissue tumors. The objective of this study was to evaluate the feasibility and imaging appearance of high-resolution 3-T magnetic resonance neurography (MRN) of the diagnosis of peripheral nerve sheath tumors (PNSTs) using sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) sequences. We retrospectively evaluated the MRI and 3D Short tau inversion recovery sampling perfection with application-optimized contrasts using varying flip-angle evolutions (3D-STIR SPACE) sequences of 30 patients with PNSTs diagnosed by surgery and pathology. The contrast-enhanced 3D-STIR SPACE images were retrospectively analyzed and evaluated for the visualization of PNSTs. The tumors were evaluated by their number, location, morphology, size, signal intensity and enhancement characteristics. The imaging findings and characteristic signs of conventional MRI scanning and contrast-enhanced 3D-STIR SPACE sequences were compared. In these cases, conventional MRI images display the location, number, shape, size and signal characteristics of the lesions. These tumors were mostly solitary and had a well-defined boundary. Compared to conventional MRI images, imaging appearances including neurogenic origin, length of the peripheral nerves and relation to the nerve of PNSTs on 3D-STIR SPACE images were more accuracy (P < 0.05). Compared to 3D-STIR SPACE images, contrast-enhanced images can more clearly display background suppression of the peripheral nerves. The “split fat” sign and “target” sign were seen in some patients. 3D STIR SPACE sequences demonstrate its significant capacity to diagnostic evaluate and location of PNSTs. This article comprehensively reviews radiologic findings and illustrates the MRN features of PNSTs. 3D-STIR SPACE sequences be used for preoperative evaluation of PNSTs.

Magnetic resonance imaging of the pediatric mediastinum

The mediastinum, the central anatomical space of the thorax, is divided by anatomical landmarks but not by physical boundaries. The mediastinum is a conduit, a space through which cranial nerves, important nerve branches, the sympathetic chain, vascular structures, and visceral structures, the trachea and esophagus pass. This arrangement allows contiguous extension or communication of disease along facial planes and through potential spaces to and from the head and neck or cervical spine, to and from the superior mediastinum, between superior and inferior mediastinal levels, and between inferior mediastinal spaces into the intra- and retroperitoneal spaces. Magnetic resonance imaging (MRI) of the mediastinum in children poses technical challenges, in particular cardiac and respiratory motion, and diagnostic challenges, including a broad range of tissue types and possible diagnoses. In this paper we review mediastinal anatomy, MRI sequences and protocol choices and include a short discussion of features and MRI findings of some of the congenital and acquired pathologies that are most often encountered in the pediatric mediastinum.

[A CASE OF PARATESTICULAR FIBROUS HAMARTOMA OF INFANCY]

Fibrous hamartoma of infancy (FHI) is a rare, benign soft tissue tumor arising from subcutaneous tissue in children during the first two years of life. The tumor is commonly found in the axilla, shoulder and upper arm. Paratesticular FHI is extremely rare. To date, only a case of paratesticular FHI has been reported in Japan. We present a case of paratesticular FHI in an 11-month-old boy who eventually needed orchiectomy due to local recurrence one month after the excision of the tumor. Ten months postoperatively, there was no sign of recurrence.