Cortical hypertrophy in intramuscular hemangioma mimicking bone tumor.

Although hemangiomas are the most common soft tissue tumors, intramuscular hemangiomas account for only 0.8% of all vascular tumors. These lesions are rarely located adjacent to the bone and cause changes in the adjacent bone. They are often mistakenly diagnosed as bone tumors. In this study, a case of a 19-year-old male patient with intramuscular hemangioma causing cortical thickening was reported.

Advancing musculoskeletal tumor diagnosis: Automated segmentation and predictive classification using deep learning and radiomics.

OBJECTIVES: Musculoskeletal (MSK) tumors, given their high mortality rate and heterogeneity, necessitate precise examination and diagnosis to guide clinical treatment effectively. Magnetic resonance imaging (MRI) is pivotal in detecting MSK tumors, as it offers exceptional image contrast between bone and soft tissue. This study aims to enhance the speed of detection and the diagnostic accuracy of MSK tumors through automated segmentation and grading utilizing MRI. MATERIALS AND METHODS: The research included 170 patients (mean age, 58 years ±12 (standard deviation), 84 men) with MSK lesions, who underwent MRI scans from April 2021 to May 2023. We proposed a deep learning (DL) segmentation model MSAPN based on multi-scale attention and pixel-level reconstruction, and compared it with existing algorithms. Using MSAPN-segmented lesions to extract their radiomic features for the benign and malignant classification of tumors. RESULTS: Compared to the most advanced segmentation algorithms, MSAPN demonstrates better performance. The Dice similarity coefficients (DSC) are 0.871 and 0.815 in the testing set and independent validation set, respectively. The radiomics model for classifying benign and malignant lesions achieves an accuracy of 0.890. Moreover, there is no statistically significant difference between the radiomics model based on manual segmentation and MSAPN segmentation. CONCLUSION: This research contributes to the advancement of MSK tumor diagnosis through automated segmentation and predictive classification. The integration of DL algorithms and radiomics shows promising results, and the visualization analysis of feature maps enhances clinical interpretability.

Recurrent Metastatic Ewing Sarcoma Involving Only in the Muscles of Extremities Shown on FDG PET/CT.

ABSTRACT: Ewing sarcoma is the second most common osseous malignancy in pediatric patient. Metastasis is common due to its aggressive nature, with 25% of patients with metastasis at diagnosis, commonly to the lungs, bone, or bone marrow. Muscle metastasis is uncommon. We report FDG PET/CT findings of multifocal muscle metastases of recurrent Ewing sarcoma in the extremities without lung and bone involvement in a 6-year-old boy.

Rapidly growing intramuscular lipoma: a unique entity of benign lipomas in children.

This report presents a case of an intramuscular lipoma observed in the left back of a healthy female toddler. It was resected after 3 months of observation because of rapid enlargement, raising suspicion of malignancy. Histopathological examination confirmed a diagnosis of intramuscular lipoma without malignant and blastemal components. Intramuscular lipomas are benign neoplasms that mostly appear as a rapidly growing tumour. Several hypotheses regarding the pathogenesis of this characteristic growth pattern have been proposed, including atrophy of the surrounding muscle, reactive adipocytic neoformation and multiple contractive interactions between the lipoma and the surrounding muscle.

Estudio clínico, radiológico y derivación en tumores musculoesqueléticos / Diagnosis and referral of musculoskeletal tumors

Musculoskeletal tumors are uncommon. However, the true burden of all bone and soft tissue tumors of extremities is underestimated. Usually, the diagnosis of sarcomas is missed or delayed. Therefore, an adequate clinical and radiological assessment, along with the awareness and application of simple guidelines for referral to a specialized center, are of utmost importance. These are critical steps for an appropriate diagnosis and treatment of sarcomas, improving their prognosis.

Skeletal muscle metastases of the trunk and pelvis: focus on ultrasound, CT findings, and clinical manifestations.

OBJECTIVE: To describe the ultrasound, CT findings, and clinical manifestations of pathologically confirmed skeletal muscle metastases involving trunk and pelvis. METHODS: 71 patients with 71 skeletal muscle metastases of the trunk and pelvis, pathologically proven by ultrasound-guided biopsy, were included in the study, and ultrasound findings were reviewed. CT findings were reviewed for 60 patients who underwent post-contrast CT obtained prior to biopsy, which included skeletal muscle metastases. Medical records, including the type of primary malignancy, presence of coexisting distant metastasis, and method of detection that led to referral for biopsy, were reviewed. RESULTS: Most skeletal muscle metastases were hypoechoic (98.6%) with well-defined margins (85.9%), round-to-oval (47.9%), or lobulated (42.2%) with intralesional vascularity (64.8%). Typical CT findings included abscess-like lesions with rim enhancement (53.3%) or round-to-oval lesions with homogeneous enhancement (40.0%). The most common primary malignancy was lung cancer (49.3%), followed by gastrointestinal cancer (7.0%). Distant metastases other than muscle metastases were found in 84.5% of patients, and coexisting skeletal muscle metastases were found in 47.9%. CT was the most common detection method for metastases (57.8%), being more common than positron emission tomography-CT (22.5%). CONCLUSION: The current study describes the typical imaging findings of skeletal muscle metastases of the trunk and pelvis in patients with advanced cancer. CT may play an important role in the early detection of skeletal muscle metastases, and our results may aid radiologists in their diagnosis. ADVANCES IN KNOWLEDGE: 1. Skeletal muscle metastases of the trunk and pelvis demonstrate typical imaging findings on ultrasound and CT.2. CT may aid in the early detection of skeletal muscle metastases, which are among the rarest, and our results may aid radiologists in their diagnosis.

Comparison of reduced field-of-view DWI and full field-of view DWI for the differentiation between non-muscle invasive bladder cancer and muscle invasive bladder cancer using VI-RADS.

PURPOSE: To evaluate whether reduced field-of-view (rFOV) DWI sequence improves the differentiation between non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) using VI-RADS. MATERIAL AND METHODS: Eighty-nine patients underwent bladder MRI with full field-of-view (fFOV) DWI and rFOV DWI sequence. Images were independently evaluated by 2 radiologists. The sensitivities, specificities, accuracies, and areas under the curve (AUCs) for the differentiation between NMIBC and MIBC with fFOV DWI and with rFOV DWI sequence were calculated using VI-RADS. Apparent diffusion coefficients (ADC) values were measured for each patient and averaged. RESULTS: The sensitivity, specificity, accuracy, and AUC by reader 1 were 92%, 78%, 82% and 0.905 with fFOV DWI, and 92%, 86%, 88% and 0.916 with rFOV DWI sequence, respectively. The sensitivity, specificity, accuracy and AUC by reader 2 were 96%, 76%, 82% and 0.900 with conventional DWI, and 96%, 81%, 85% and 0.907 with rFOV DWI sequence, respectively. The specificity and accuracy of reader 1 were significantly better with rFOV DWI sequence than with fFOV DWI, in contrast there was no significant difference for the others. The average of ADC values of fFOV DWI and rFOV DWI sequence were 1.004×10-6 mm2/s and 1.003×10-6 mm2/s, respectively. CONCLUSION: The diagnostic ability of rFOV DWI sequence may be better than that of fFOV DWI using VI-RADS for the differentiation between NMIBC and MIBC regardless of image-reading experience, it is controversial.

[Diagnosis and referral of musculoskeletal tumors]. / Estudio clínico, radiológico y derivación en tumores musculoesqueléticos.

Musculoskeletal tumors are uncommon. However, the true burden of all bone and soft tissue tumors of extremities is underestimated. Usually, the diagnosis of sarcomas is missed or delayed. Therefore, an adequate clinical and radiological assessment, along with the awareness and application of simple guidelines for referral to a specialized center, are of utmost importance. These are critical steps for an appropriate diagnosis and treatment of sarcomas, improving their prognosis.

Do contrast-enhanced and advanced MRI sequences improve diagnostic accuracy for indeterminate lipomatous tumors?

PURPOSE: Benign, intermediate-grade and malignant tumors sometimes have overlapping imaging and clinical characteristics. The purpose of this study was to evaluate the added value of contrast-enhanced sequences (dynamic contrast enhancement (DCE)), diffusion-weighted imaging (DWI), and chemical shift imaging (CSI) to noncontrast MRI sequences for the characterization of indeterminate lipomatous tumors. MATERIALS AND METHODS: Thirty-two consecutive patients with histologically proven peripheral lipomatous tumors were retrospectively evaluated. Two musculoskeletal radiologists recorded the MRI features in three sessions: (1) with noncontrast T1-weighted and fluid-sensitive sequences; (2) with addition of static pre- and post-contrast 3D volumetric T1-weighted sequences; and (3) with addition of DCE, DWI, and CSI. After each session, readers recorded a diagnosis (benign, intermediate/atypical lipomatous tumor (ALT), or malignant/dedifferentiated liposarcoma (DDL)). Categorical imaging features (presence of septations, nodules, contrast enhancement) and quantitative metrics (apparent diffusion coefficient values, CSI signal loss) were recorded. RESULTS: For 32 tumors, the diagnostic accuracy of both readers did not improve with the addition of contrast-enhanced sequences, DWI, or CSI (53% (17/32) session 1; 50% (16/30) session 2; 53% (17/32) session 3). Noncontrast features, including thick septations (p = 0.025) and nodules ≥ 1 cm (p < 0.001), were useful for differentiating benign tumors from ALTs and DDLs, as were DWI (p = 0.01) and CSI (p = 0.009) metrics. CONCLUSION: The addition of contrast-enhanced sequences (static, DCE), DWI, and CSI to a conventional, noncontrast MRI protocol did not improve diagnostic accuracy for differentiating benign, intermediate-grade, and malignant lipomatous tumors. However, we identified potentially useful imaging features by DCE, DWI, and CSI that may help distinguish these entities.

[Mazabraud syndrome]. / Síndrome de Mazabraud.

Mazabraud syndrome was first described in 1926 by Henschen, consisting of the association between bone fibrodysplasia and one or more intramuscular myxomas. The study paper conducted by Mazabraud et al. in 1967, described an association between the two pathologies. Later literature referred to this relationship with the eponym described above. In this report, we present the case of a 43-year-old female patient with a known diagnosis of bone fibrodysplasia and subsequent development of a right antecubital fossa mass, which was histologically confirmed as intramuscular myxoma. After the removal of the tumor, the literature was reviewed to find a possible relationship between myxomas and fibrous bone dysplasia, finding positive the association, referred to in the documents reviewed as Mazabraud syndrome.

El síndrome de Mazabraud fue descrito inicialmente en 1926 por Henschen, consiste en la asociación entre fibrodisplasia ósea y uno o más mixomas intramusculares. El documento de estudio realizado por Mazabraud y colaboradores en 1967 describió una asociación entre las dos patologías. Literatura posterior se refirió a esta relación con el epónimo antes descrito. En este reporte, presentamos el caso de una mujer de 43 años, con diagnóstico conocido de fibrodisplasia ósea y posterior desarrollo de una masa en fosa antecubital derecha, la cual fue confirmada histológicamente como mixoma intramuscular. Después de la extracción de la tumoración, se revisó la literatura para encontrar una posible relación entre mixomas y displasia ósea fibrosa, encontrando positiva la asociación, denominada en los documentos revisados como síndrome de Mazabraud.

The development of musculoskeletal radiology for 100 years as presented in the pages of Acta Radiologica.

During the last 100 years, musculoskeletal radiology has developed from bone-only radiography performed by everyone to a dedicated subspecialty, still secure in its origins in radiography but having expanded into all modalities of imaging. Like other subspecialties in radiology, it has become heavily dependent on cross-sectional and functional imaging, and musculoskeletal interventions play an important role in tumor diagnosis and treatment and in joint diseases. All these developments are reflected in the pages in Acta Radiologica, as shown in this review.

Standard diffusion-weighted, intravoxel incoherent motion, and dynamic contrast-enhanced MRI of musculoskeletal tumours: correlations with Ki67 proliferation status.

AIM: To determine whether quantitative parameters derived from conventional diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) correlate with the Ki67 proliferation status in musculoskeletal tumours. MATERIALS AND METHODS: Twenty-eight patients with musculoskeletal tumours diagnosed via surgical specimen histological analysis who underwent standard DWI, IVIM, and DCE were reviewed retrospectively. The mean standard DWI (apparent diffusion coefficient [ADC]), IVIM (pure diffusion coefficient [D], pseudo-diffusion coefficient [D∗] and perfusion fraction [ƒ]), and DCE (volume transfer constant [Ktrans], rate constant [Kep], and extravascular extracellular volume fraction [Ve]) parameters were measured and correlated with the Ki67 index. The Ki67 value was categorised as high (>20%) or low (≤20%). RESULTS: The ADC and D values correlated negatively with the Ki67 index (r=-0.711∼-0.699, p<0.001), whereas the Ktrans and Kep values correlated positively with the Ki67 index (r=0.389-0.434, p=0.021, 0.041). The ADC and D values were lower (p<0.001), whereas the Ktrans and Kep values were higher (p=0.011, 0.005) in musculoskeletal tumours with a high Ki67 status than in those in a low status. The ADC and D demonstrated the largest area under the receiver-operating characteristic curve (AUC = 0.953), which is statistically bigger than the AUC of Ktrans and Kep (0.784 and 0.802, respectively). CONCLUSION: ADC, D, Ktrans, and Kep correlate with the Ki67 index. ADC and D are the strongest quantitative parameters for predicting Ki67 status.

PET-CT for the diagnosis and treatment of primary musculoskeletal tumors in Chinese patients - experience from 255 patients in a single center.

OBJECTIVE: The current study was carried out to assess the value of positron emission tomography (PET)/CT on the diagnosis and staging of primary musculoskeletal tumors. METHODS: PET-CT test results and histopathological study reports of all the patients with primary musculoskeletal tumors in our department from January 2006 to July 2015 were retrospectively reviewed. Maximum standardized uptake value (SUVmax) in these PET-CT reports were recorded and analyzed respectively for each type of sarcoma. RESULTS: A total of 255 patients were included in the final analysis. Sensitivity of SUVmax based diagnosis was 96.6% for primary malignant osseous sarcomas and 91.2% for soft tissue sarcomas. SUVmax of high-grade osseous sarcomas (average 8.4 ± 5.5) was significantly higher (p < 0.001) than low-grade osseous sarcomas (average 3.9 ± 1.8); based on current case series, SUVmax of high-grade soft tissue sarcomas (7.5 ± 5.1) was not significantly different (p = 0.229) from that of low-grade soft tissue sarcomas (5.3 ± 3.7). Significant decrease of SUVmax value after chemotherapy was associated with favorable prognosis in patients with osteosarcoma. CONCLUSION: Results of the current study indicate that, the SUVmax based application of PET-CT can be a valuable supplementary method to histopathological tests regarding the diagnosis and staging of primary musculoskeletal sarcomas. ADVANCES IN KNOWLEDGE: SUVmax based application of PET-CT is a highly sensitive method in diagnosis of primary osseous and soft tissue sarcomas in Chinese patients.

Intramuscular lipoma of the scapular region.

Intramuscular lipomas are rare, benign soft tissue neoplasms characterized by infiltrative growth into muscle tissue or between muscle fibers. These benign tumors can present similarly to malignant soft tissue neoplasms, such as liposarcomas. Unlike subcutaneous lipomas, intramuscular lipomas require diagnostic imaging to better distinguish the tumor and rule out alternative, malignant etiologies. It is imperative that dermatologists are able to identify this rare lipoma variant and have a thorough understanding of the diagnosis, imaging, and treatment options for this uncommon soft tissue tumor. Our case serves as a reminder for dermatologists to be cognizant of this rare tumor and aware of the importance of diagnostic testing in ruling out similarly-presenting, soft tissue malignancies.

An update in musculoskeletal tumors: from quantitative imaging to radiomics.

In the last two decades, relevant progress has been made in the diagnosis of musculoskeletal tumors due to the development of new imaging tools, such as diffusion-weighted imaging, diffusion kurtosis imaging, magnetic resonance spectroscopy, and diffusion tensor imaging. Another important role has been played by the development of artificial intelligence software based on complex algorithms, which employ computing power in the detection of specific tumor types. The aim of this article is to report the most advanced imaging techniques focusing on their advantages in clinical practice.

Gastric adenocarcinoma presenting with multiple skeletal muscle metastases.

A 42-year-old man presented to the gastroenterology clinic with features of gastric outlet obstruction, significant weight loss, anaemia, ascites, and pain in the lower back and left thigh. CT scan of the abdomen and pelvis showed wall thickening in the antropyloric region of the stomach and enhancing soft tissue lesion in the left psoas and right gluteal region. Gastroscopy revealed a circumferential growth in the antrum and pylorus of the stomach, and biopsy from the growth was reported as moderately differentiated adenocarcinoma. Positron emission tomography-CT scan showed multiple skeletal muscle metastases all over the body. Fine-needle aspiration cytology and immunohistochemistry from the psoas lesion confirmed metastatic adenocarcinoma deposits. He underwent antropyloric stenting for his obstructive symptoms and received supportive care, finally succumbed to his illness after 6 weeks.

Oral intramuscular myxoma: case report and brief review of the literature.

OBJECTIVE: Myxomas are rare benign mesenchymal soft tissue tumors that seldom affect the head and neck area. The present report describes a rare case of intramuscular myxoma of the oral cavity and briefly reviews the literature regarding the occurrence of these lesions in the maxillofacial area. STUDY DESIGN: A 59-year-old patient was referred for the development of a slow-growing tumefaction in the right buccal mucosa in the previous 12 months. Magnetic resonance imaging was performed to characterize the lesion's dimensions and its relationship with the surrounding structures, and it revealed intramuscular localization in correspondence with the medial pterygoid muscle. Incisional biopsy was carried out to aid in the final diagnosis. RESULTS: Histology revealed the presence of an intramuscular myxoma, characterized by discontinuous margins and locally infiltrating muscular fibers. A second surgery was performed to totally remove the lesion. Follow-up at 6 months did not show any signs of recurrence. A literature search was performed to retrieve data on the incidence of oral intramuscular myxomas. CONCLUSIONS: To the best of our knowledge, this is the first case of intramuscular myxoma of the medial pterygoid muscle reported in the literature. Although rarely encountered, intramuscular myxomas should be considered when performing differential diagnoses of soft tissue masses at the level of the masticatory muscles.