Differential diagnosis between benign and malignant soft tissue tumors utilizing ultrasound parameters

Evaluating the role and diagnostic performance of ultrasound in diagnosing soft tissue tumors and pseudotumors in adults: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis evaluates the combined accuracy of ultrasonic imaging in diagnosing soft tissue tumors and pseudotumors and identifies factors contributing to variability in its diagnostic accuracy.

METHODS

A literature search in significant databases used specific keywords and inclusion/exclusion criteria. Two authors independently performed cohort characterization and data analysis, with a third author resolving disagreements. A multivariate random effects model estimated pooled sensitivity, specificity, predictive values, and overall accuracy.

RESULTS

Ultrasound imaging demonstrated high pooled sensitivity and specificity, indicating effectiveness in identifying lesions. Variability in accuracy was attributed to factors such as tumor type and location, operator experience, and clinic location.

CONCLUSIONS

Ultrasonic imaging is a reliable diagnostic tool for soft tissue tumors and pseudotumors, providing high sensitivity and specificity. However, variability in accuracy underscores the need to consider operator experience and tumor characteristics. Further research should explore the impact of technological advancements and include non-English studies to enhance understanding of ultrasound imaging's diagnostic validity.

Ultrasound features of benign paediatric lumps: radiology-pathology correlation

Ultrasonography is an appropriate first-line imaging technique for the characterisation of paediatric lumps, given its relative accessibility and absence of radiation exposure. Together with a thorough history and examination, ultrasonography can help to distinguish benign lesions from malignancy. It can also aid further characterisation of benign lesions to inform onward investigation and management. This review features the evaluation of common benign paediatric lumps together with their characteristic sonographic features, following correlation with histopathology results or clinical follow-up.

Malignant and Benign Peripheral Nerve Sheath Tumors in a Single Center: Value of Clinical and Ultrasound Features for the Diagnosis of Malignant Peripheral Nerve Sheath Tumor Compared With Magnetic Resonance Imaging

OBJECTIVES

This study aimed to investigate the combined use of ultrasonography and clinical features for the differentiation of malignant peripheral nerve sheath tumors (MPNST) from benign peripheral nerve sheath tumors (BPNST) and to compare the efficacy of ultrasonography with that of magnetic resonance imaging (MRI).

METHODS

This retrospective study included 28 MPNSTs and a control group of 57 BPNSTs. All patients underwent an ultrasound scan using the Logiq E9 (GE Health Care, Milwaukee, WI) or EPIQ7 equipment (Philips Medical System, Bothell, WA). A 3.0-T MRI machine (Ingenia; Philips Healthcare, Best, the Netherlands) was used for scanning, and conventional MRI was performed on different regions based on the patient's clinical situation. The following variables were evaluated: palpable mass, pain, nerve symptoms, maximum diameter, location, shape, boundary, encapsulation, echogenicity, echo homogeneity, presence of a cystic component, calcification, target sign, posterior echo, and intertumoral vascularity of the tumors. The diagnostic efficacy of ultrasonography and clinical factors was compared with that of MRI. Independent factors for predicting MPNST versus BPNST were also assessed.

RESULTS

The parameters of location, shape, boundary, encapsulation, and vascularity were significantly different between MPNSTs and BPNSTs. Multiple logistic regression analysis showed that shape, boundary, and vascularity were independent predictors of MPNSTs. The sensitivity, specificity, and Youden index of the three clinical and ultrasound factors (shape, boundary, and vascularity) were 0.89, 0.81, and 0.69, respectively, whereas those of MRI were 0.71, 0.89, and 0.61, respectively. No significant differences in the area under the curve (AUC) of the three combined clinical and ultrasound factors and those of MRI were found (P > .05).

CONCLUSIONS

MRI was useful in the differential diagnosis between MPNSTs and BPNSTs. However, the combination of clinical and ultrasound diagnoses can achieve the same effect as MRI, including shape, boundary, and vasculature.

Ultrasound performance in pediatric deep soft-tissue tumor characterization

This study investigated the performance of ultrasonography in diagnosing deep soft-tissue tumors and tumor-like lesions in children with histological results. Demographic information and ultrasound characteristics of benign and malignant masses were statistically analyzed. Three radiologists (Radiologists 1, 2, and 3) independently reviewed the ultrasonography studies while being blinded to the medical history and other imaging findings. The 82 lesions included in the study were histopathologically classified as malignant (n = 25) or benign (n = 57). No statistically significant differences were observed between the benign and malignant subgroups regarding age (p = 0.059), sex (p = 1.0), disease course (p = 0.812), presence or absence of symptoms (p = 0.534), maximum diameter (p = 0.359), margin (p = 1.0), calcification (p = 0.057), or blood Adler type (p = 0.563). However, statistically significant differences were observed between the benign and malignant subgroups in terms of isolated or Multiple occurrences (p < 0.001), history of malignancy (p < 0.001), shape (p < 0.001), and echogenicity (p < 0.001). Parameters such as tumor shape (p = 0.042, OR = 6.222), single or multiple occurrences (p = 0.008, OR = 17.000), and history of malignancy (p = 0.038, OR = 13.962) were identified as independent predictors of benign and malignant tumors. The diagnostic sensitivities evaluated by the three radiologists were 68.0%, 72.0%, 96.0%, respectively, while the specificities were 77.2%, 82.5%, 77.2%, respectively. Ultrasound demonstrates good performance in the diagnosis of benign deep lesions such as hemangiomas/venous malformation and adipocytic tumors. Multiple irregular morphologies and a history of malignancy were identified as independent risk factors for malignant masses. The experience of radiologists in recognizing specific tumors is important. Careful attention should be paid to masses with ambiguous ultrasound features, as well as small lesions.

Diagnostic value of high-frequency ultrasound (HFUS) in evaluation of subcutaneous lesions

BACKGROUND

It is unknown whether high-frequency ultrasound (HFUS) can evaluate invisible subcutaneous lesions. We aimed to investigate the diagnostic value of HFUS in invisible subcutaneous lesions.

METHOD

Patients with invisible subcutaneous lesions were prospectively recruited from two centres. Before undergoing biopsy or surgery, each lesion was independently evaluated by two clinicians. One provides a clinical diagnosis by only clinical examination and the other provides an integrated diagnosis by combining clinical examination and HFUS information. Diagnoses were classified as correct, wrong, and indeterminate. A total of 391 lesions from 355 patients were enrolled, including 225 epidermoid cysts, 77 lipomas, 25 pilomatrixomas, 21 haemangiomas, 19 dermatofibromas, 11 dermatofibrosarcoma protuberans (DFSP), 7 neurofibromas, and 6 leiomyomas. Using pathological results as the gold standard, diagnostic performance was compared.

RESULTS

The number of correct diagnoses increased from 185 (47.3%) by clinical examination alone to 316 (80.8%) after the addition of HFUS (P < 0.05). Meanwhile, the indeterminate diagnosis rate decreased from 143 (36.6%) to 10 (2.6%). Using HFUS, the accuracy improved significantly for epidermoid cysts (59.6% vs. 86.7%), lipomas (50.6% vs. 94.8%), pilomatrixomas (0% vs. 48.0%), haemangiomas (23.8% vs. 57.1%), and DFSPs (0% vs. 81.8%) (all p < 0.05). However, HFUS did not significantly improve the diagnostic accuracy of dermatofibromas (15.8% vs. 21.1%, p > 0.999), neurofibromas (42.9% vs. 71.4%, p = 0.625), or leiomyomas (16.7% vs. 100%, p = 0.063).

CONCLUSION

Combining HFUS and clinical examination can generally improve the diagnostic accuracy and decrease the indeterminacy of invisible subcutaneous lesions, especially epidermoid cysts, lipomas, pilomatrixomas, haemangiomas, and DFSPs. However, for some rare lesions, HFUS cannot provide useful information.

Analysis on diagnostic failure of US-guided core needle biopsy for soft tissue tumors

Purpose

To evaluate the diagnostic yield of ultrasonography (US)-guided core needle biopsy (CNB) in the diagnosis of soft tissue tumors (STTs) and to analyze the failure factors.

Methods

139 patients with STTs that underwent both US-guided CNB and surgical resection were collected retrospectively. Compared with the histopathological results of surgical resection, the biopsy failure was defined as the following conditions: indefinitive diagnosis, including insufficient samples and unknown subtypes with correct biological potential classification; wrong diagnosis, including wrong biological potential classification and wrong subtypes with correct biological potential classification. Univariate and multivariate analyses from the perspectives of histopathological, demographic and US features together with biopsy procedures were performed to determine risk factors for diagnostic failure.

Results

The diagnostic yield of US-guided CNB for STTs in our study was 78.4%, but when only considering the correct biological potential classification of STTs, the diagnostic yield was 80.6%. The multivariate analysis showed that adipocytic tumors (odds ratio (OR) = 10.195, 95% confidence interval (CI): 1.062 - 97.861, p = 0.044), vascular tumors (OR = 41.710, 95% CI: 3.126 - 556.581, p = 0.005) and indeterminate US diagnosis (OR = 8.641, 95% CI: 1.852 - 40.303, p = 0.006) were correlated with the diagnostic failure. The grade III vascular density (OR = 0.019, 95% CI: 0.001 - 0.273, p = 0.007) enabled a higher diagnostic accuracy.

Conclusion

US-guided CNB can be an effective modality for the diagnosis of STTs. The diagnostic yield can be increased when the tumor vascular density was grade III in Color Doppler US, but can be decreased in adipocytic tumors, vascular tumors and masses with indeterminate US diagnosis.

Added value of contrast-enhanced ultrasound to conventional ultrasound for characterization of indeterminate soft-tissue tumors

OBJECTIVE

To assess the added value of contrast-enhanced ultrasound (CEUS) to conventional ultrasound in differentiating benign soft-tissue tumors from malignant ones.

METHODS

197 soft-tissue tumors underwent ultrasound examination with confirmed histopathology were retrospectively evaluated. The radiologists classified all the tumors as benign, malignant, or indeterminate according to ultrasound features. The indeterminate tumors underwent CEUS were reviewed afterwards for malignancy identification by using individual and combined CEUS features.

RESULTS

Ultrasound analysis classified 62 soft-tissue tumors as benign, 111 tumors as indeterminate and 24 tumors as malignant. There 104 indeterminate tumors were subject to CEUS. Three CEUS features including enlargement of enhancement area, infiltrative enhancement boundary, and intratumoral arrival time difference were significantly associated with the tumor nature in both univariable and multivariable analysis for the indeterminate tumors (all p < 0.05). When at least one out of the three discriminant CEUS features were present, the best sensitivity of 100% for malignancy identification was obtained with the specificity of 66.7% and the AUC of 0.833. When at least two of the three discriminant CEUS features were present, the best area under the receiver operating characteristic curve (AUC) of 0.924 for malignancy identification was obtained. The combination of at least two discriminant CEUS features showed much better diagnostic performance than the optimal combination of ultrasound features in terms of AUC (0.924 vs 0.608, p < 0.0001), sensitivity (94.0% vs 42.0%, p < 0.0001), and specificity (90.7% vs 79.6%, p = 0.210) for the indeterminate tumors.

CONCLUSION

The combination CEUS features of enlargement of enhancement area, infiltrative enhancement boundary and intratumoral arrival time difference are valuable to improve the discriminating performance for indeterminate soft-tissue tumors on conventional ultrasound.

ADVANCES IN KNOWLEDGE

The combination of peritumoral and arrival-time CEUS features can improve the discriminating performance for indeterminate soft-tissue tumors on conventional ultrasound.

Clinical-Radiomics Nomogram from T1W, T1CE, and T2FS MRI for Improving Diagnosis of Soft-Tissue Sarcoma

PURPOSE

To compare values of multiparametric magnetic resonance imaging (MRI) sequences and propose clinical-radiomics nomogram for diagnosis of soft-tissue sarcoma (STS).

PROCEDURES

This study enrolled 148 patients from Dec. 2017 to Feb. 2021. All patients underwent T1-weighted (T1W), contrast-enhanced T1-weighted (T1CE), and T2-weighted fat-suppressed (T2FS) MRI scans. A total of 1967 radiomic features were extracted from the segmented regions of interest (ROIs) in each MRI sequence. Highly diagnostic radiomic features were selected with Mann-Whitney U test, elastic net, and Akaike's information criterion (AIC) based on MRI images. Logistical regression was used to build Rad scores. Clinical factors were analyzed using the chi-square test or Mann-Whitney U test. The performance of the Rad scores was judged using the area under the receiver operating characteristic area under the curve (ROC AUC), sensitivity, specificity, and accuracy. The nomogram was developed by integrating the Rad score and the most important clinical factor.

RESULTS

By combining the three MRI sequences, the Rad-Com was developed consisting of twelve features selected by with Mann-Whitney U test, elastic net, and AIC: four from T1W, three from TICE, and five from T2FS MRI. The margin (P < 0.05) demonstrated a statistically significant difference between patients with benign and malignant soft-tissue tumors (STT). The nomogram was constructed by integrating the Rad-Com and margin, which yielded favorable diagnostic AUCs of 0.919 (sensitivity (Sen) = 0.784, specificity (Spe) = 0.936) and 0.913 (Sen = 0.923, Spe = 0.792) in the training and validation cohort.

CONCLUSION

The proposed nomogram may have potential as a noninvasive marker for STS diagnosis.

The diagnostic accuracy of intravoxel incoherent motion and diffusion kurtosis imaging in the differentiation of malignant and benign soft-tissue masses: which is better?

BACKGROUND

It is difficult for conventional magnetic resonance imaging (MRI) to distinguish benign soft-tissue masses (STMs) from malignant masses.

PURPOSE

To quantitatively compare the diagnostic value of intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) in STMs.

MATERIAL AND METHODS

The data from 58 patients with STMs were retrospectively analyzed. The GE Discovery 3.0-T MRI scanner was used to acquire conventional MRI sequences, IVIM, and DKI images. The chi-square test, independent sample t-test, and Mann-Whitney U tests were used to compare the differences between conventional MRI features, IVIM, and DKI parameters (D_slow, D_fast, f, mean kurtosis [MK], and mean diffusivity [MD]) between the benign and malignant groups. Receiver-operating characteristic (ROC) curve analysis was also performed.

RESULTS

Tumor size and depth are statistically different in STTs. Ds_low, MK, and MD values in the malignant groups are significantly lower than the benign groups (P < 0.05). However, D_fast and f values are not statistically different between the two groups. The area under the curve (AUC) of D_slow value (0.859) is higher than MD (0.765) and MK (0.676) values for identifying benign and malignant STMs. The D_slow value showed the best specificity (82.93%). The sensitivity and specificity of IVIM and DKI parameters are higher than that of conventional MRI sequences.

CONCLUSION

IVIM and DKI can be used to distinguish between benign and malignant STMs, with D_slow as the most meaningful parameter.

Diagnostic Performance of US and MRI in Predicting Malignancy of Soft Tissue Masses: Using a Scoring System

Objective

To assess the diagnostic performance of US and MRI in predicting malignancy of soft tissue masses by using a scoring system.

Methods

A total of 120 cases of pathologically confirmed soft tissue masses (71 cases of malignant lesions and 49 cases of benign lesions) were enrolled. All patients underwent ultrasound and MRI examination prior to biopsy or surgical excision. A scoring system based on the parameters of conventional US and MRI to distinguish malignant and benign masses was established by the regression model. The receiver operating characteristic (ROC) analysis was used to evaluate the diagnostic performance of US and MRI.

Results

Multivariate analysis showed that margin, maximum diameter, and vascular density were independent predictors for malignancy found by US, while maximum diameter, margin, and affected peripheral soft tissue were independent predictors for malignancy found by MRI. The mean scores of the benign and malignant groups were 2.8 ± 1.6, 5.1 ± 1.1 on US and 1.3 ± 1.2, 3.5 ± 0.9 on MRI. Based on the cut-off score of 3.5 and 2.5 calculated by ROC analysis, US and MRI had 92% and 87% sensitivity, 72% and 76% specificity, 86% and 89% accuracy, respectively. The combination of these two modalities achieved the sensitivity of 91%, specificity of 82%, and accuracy of 93%.

Conclusions

Both US and MRI can provide valuable information about the differential diagnosis between benign and malignant soft tissue masses. The combination of the two imaging-based scoring systems can increase the diagnostic performance, especially in specificity.

The relationship of systemic inflammatory biomarkers and cardiac parameters with malignancy in patients with soft tissue tumors located in the extremity

Objectives

In this study, we aimed to investigate the contribution of systemic inflammatory biomarkers to the diagnosis and to examine the relationship between cardiac parameters and malignancy in patients with extremity soft tissue sarcomas (STSs).

Patients and methods

Between January 2011 and December 2020, a total of 256 patients (155 males, 101 females; median age: 50 years; range, 18 to 87 years) who were diagnosed with benign and malignant soft tissue tumors were retrospectively analyzed. The control group consisted of a total of 150 age- and sex-matched healthy individuals (83 males, 67 females; median age: 52 years; range 19 to 76 years) with complete blood count analysis and having no STS. Demographic characteristics, laboratory parameters, and echocardiographic data of the patients were obtained from the hospital database. The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) were calculated.

Results

Of a total of 256 patients included, 99 were diagnosed with benign tumors and 157 with malignant tumors. Lipoma was observed with the highest frequency of 40.4% among benign tumors, while malignant mesenchymal tumor (35.0%) was the most common tumor in the malignant group. There was no significant difference between the control and benign groups (p=0.198 and p=0.553, respectively), while the NLR and PLR of the malignant group were higher than both the control and benign groups, indicating a statistical significance (p<0.001). Total cholesterol, albumin, and ejection fraction (EF) levels of patients in the malignant group were significantly lower than the benign group (p=0.01, p<0.001, and p=0.046, respectively). According to the receiver operating characteristic curve, a cut-off value of 2.17 for NLR (sensitivity=64.1%, specificity=72%) and a cut-off value of 138.2 for PLR (sensitivity=60.9%, specificity=60.7%) were determined to distinguish malignant patients from healthy individuals. To distinguish malignant patients from the benign group, the cut-off values of NLR and PLR were 2.24 (sensitivity=62.8%, specificity=67.7%) and 137.9 (sensitivity=61%, specificity= 59.6%), respectively.

Conclusion

Our study results suggest that NLR and PLR can be used as diagnostic markers in malignant soft tissue tumors located in the extremities. In addition, total cholesterol, albumin, and EF values are lower than normal in malignant soft tissue tumors.

Imaging update on soft tissue sarcoma

Soft tissue sarcomas (STS) are rare tumours presenting as soft tissue lumps. Ultrasound is often the primary modality for the initial assessment, with MRI the mainstay for lesion characterisation. PET/CT along with other emerging MRI sequences are used in certain situations as an adjunct and problem solving tool in STS staging and assessment of disease recurrence. Recent advances include the promise of whole body MRI, hybrid PET/MRI, diffusion weighted imaging, dynamic contrast enhanced MRI and advances in artificial intelligence. This article discusses current concepts in extremity STS imaging and highlights recent advances.

The diagnostic performance of conventional ultrasound and strain elastography in malignant soft tissue tumors

OBJECTIVE

To investigate the diagnostic value of conventional ultrasound (US) and strain elastography (SE) in malignant soft tissue tumors.

METHOD

A total of 83 soft tissue masses were included prospectively. US and SE imaging were performed at the same time. Two observers assessed the B mode, color Doppler, elastic scores (ES), strain ratio (SR), and SE size to B mode size (EI/B) ratio and compared the consistency of the data between the observers. According to the pathological diagnosis of resection, the cases were divided into malignant and nonmalignant groups. The diagnostic value of conventional US and SE in the prediction of malignant soft tissue tumors was assessed.

RESULTS

The pathology results divided cases into 36 malignant lesions and 47 nonmalignant lesions. There was no statistically significant difference in gender, location, maximum diameter, echo, tail sign, cystic component, Doppler scores, or SR between the two groups (p > 0.05). However, significant differences between the two groups were found in age, depth, heterogeneity, edge, ES, and EI/B (p < 0.05). The biggest area under the receiver operating characteristics curve (0.934) was the combination model of age, heterogeneity, edge, ES, and EI/B, and the sensitivity and specificity were 0.861 and 0.957, respectively.

CONCLUSIONS

Conventional US and SE are significant for the diagnosis of malignant soft tissue tumors, and SE can be used as a complementary technique to the characterization of STTs using conventional US.

Nomogram Based on Ultrasonography and Clinical Features for Predicting Malignancy in Soft Tissue Tumors

Purpose

The objective of this study was to establish a predictive nomogram based on ultrasound (US) and clinical features for patients with soft tissue tumors (STTs).

Patients and Methods

A total of 260 patients with STTs were enrolled in this retrospective study and were divided into a training cohort (n=200, including 110 malignant and 90 benign masses) and a validation cohort (n=60, including 30 malignant and 30 benign masses). Multivariate analysis was performed by binary logistic regression analysis to determine the significant factors predictive of malignancy. A simple nomogram was established based on these independent risk factors including US and clinical features. The predictive accuracy and discriminative ability of the nomogram were measured by the calibration curve and the concordance index (C-index).

Results

The nomogram, comprising US features (maximum diameter, margin and vascular density) and clinical features (sex, age, and duration of disease), showed a favorable performance for predicting malignancy, with a sensitivity of 88.2% and a specificity of 78.7%. The calibration curve for malignancy probability in the training cohort showed good agreement between the nomogram predictions and actual observations. The C-indexes of the training cohort and validation cohort for predicting malignancy were 0.89 (95% CI: 0.85–0.94) and 0.83 (95% CI: 0.73–0.94), respectively.

Conclusion

The nomogram based on US and clinical features could be a simple, intuitive and reliable tool to individually predict malignancy in patients with STTs.

Distinction between benign and malignant soft tissue tumors based on an ultrasonographic evaluation of vascularity and elasticity

The initial diagnostic distinction between benign and malignant soft tissue tumors is critical for decisions regarding the appropriate course of treatment. The current study aimed to evaluate the vascularity and elasticity of soft tissue tumors by superb microvascular imaging and shear wave elastography using ultrasonography (US), to determine their usefulness in distinguishing malignant soft tissue tumors, and to further establish the diagnostic accuracy and usefulness of a scoring system (SS) based on these evaluations. The present study used 167 lesions of soft tissue tumors examined by US prior to biopsy, surgery and pathological tissue diagnosis. The vascularity index (VI) and the maximal shear velocity (MSV), as indices of vascularity and elasticity respectively, were evaluated using US. The tumor size and depth were also evaluated via magnetic resonance imaging (MRI). Based on the odds ratio of these parameters determined by multivariate logistic regression analysis, an original SS was established to identify the malignancy of soft tissue tumors. VI and MSV exhibited significantly high values for malignant tumors. Tumor size was also significantly larger for malignant than benign tumors. The areas under the curves (AUCs) of the receiver operating characteristic analysis for VI, MSV and tumor size were 0.75, 0.84 and 0.69, respectively, indicating that these methods were effective for the diagnosis of malignancy. An original SS consisting of VI, MSV and tumor size, excluding tumor depth, was established, and revealed an AUC value of 0.90, with 93.6% sensitivity and 79.2% specificity for malignancy distinction. US evaluation of vascularity and elasticity was an effective technique to distinguish malignant soft tissue tumors, and the current SS based on US evaluations including tumor size via MRI demonstrated a high diagnostic accuracy for malignant soft tissue tumors.

Diagnostic Value of Contrast-Enhanced Ultrasound for Differential Diagnosis of Malignant and Benign Soft Tissue Masses: A Meta-Analysis

This meta-analysis was aimed at investigating the value of using contrast-enhanced ultrasound (CEUS) in the differential diagnosis of benign and malignant soft tissue masses (STMs). Relevant studies published before March 24, 2020 were identified through a comprehensive search of PubMed, Ovid, Cochrane and Web of Science. According to the inclusion criteria, five studies were selected comprising 746 patients. In the differential diagnosis of benign and malignant STMs, the pooled sensitivity and specificity of CEUS were 76% (95% confidence interval [CI]: 71%-81%; heterogeneity [I²] = 74.5%) and 67% (95% CI: 62%-71%; I² = 36.5%), respectively. The diagnostic odds ratio was 7.37 (95% CI: 3.78%-14.35; I² = 66.6%). The overall area under the curve was 0.77 (standard error: 0.0392). Subgroup analysis revealed that different index tests of CEUS resulted in different diagnostic performance. Importantly, CEUS is an effective method for the differential diagnosis between benign and malignant STMs.

The diagnostic value of ultrasound and shear wave elastography in the differentiation of benign and malignant soft tissue tumors

AIM

To evaluate the diagnostic value of ultrasound (US) and shear wave elastography (SWE) in the differentiation of benign and malignant soft tissue tumors.

MATERIALS AND METHODS

A hundred and nine patients (mean age 43.3 ± 20.5, range 0-85; 64 men and 45 women) diagnosed with soft tissue tumors between August 2016 and January 2020 were evaluated with US and SWE. The stiffness of the lesions was measured as mean and maximum shear wave velocity (SWV_mean and SWV_max) in meters/second (m/s). Two radiologists evaluated the US images independently and then reached a final consensus. Final diagnosis was obtained either by histopathological examination (core needle biopsy or surgery) or by follow-up. The diagnostic value of US and SWE in the differentiation of malignant and benign lesions was assessed.

RESULTS

Pathology results revealed 37 malignant and 43 benign lesions. Twenty-nine lesions were benign based on follow-up criteria. Consensus US reading revealed 91.9% sensitivity and 72.2% specificity with almost perfect inter-observer agreement (κ = 0.802). Larger lesion size, male gender, advanced patient age, deep location, hypoechoic and hypervascular appearance, ill-defined margins, and presence of cystic area were associated with malignant diagnosis (p < 0.001, p = 0.010, p = 0.001, p = 0.001, p = 0.003, p < 0.001, p = 0.001, and p = 0.011, respectively). Median SWV_mean and median SWV_max of malignant lesions (2.87 and 2.68) were not significantly different than those of the benign lesions (3.30 and 3.05; p = 0.271 and p = 0.402, respectively).

CONCLUSION

US features can differentiate malignant and benign soft tissue tumors, whereas SWE did not contribute to the differentiation of soft tissue tumors.

Discrimination of well-differentiated liposarcoma from benign lipoma on sonography: an uncontrolled retrospective study

PURPOSE

Well-differentiated liposarcoma, the most common subtype of liposarcoma, should be discriminated from benign lipoma. However, features on sonography for discriminating these two types of tumor have not been fully investigated. The present study was therefore aimed at clarifying differences in sonographic findings between well-differentiated liposarcoma and lipoma.

METHODS

The study population comprised 23 cases of well-differentiated liposarcoma and 181 cases of lipoma. We investigated differences in sonographic appearance and pathological findings between the two types of tumor.

RESULTS

Well-differentiated liposarcoma tended to develop more frequently in older patients and in the lower extremities including the gluteal region, compared with lipoma. Concerning sonographic findings, both tumors exhibited well-defined margins and heterogeneous internal echogenicity, including typical tiny striated hyperechoic lines. Well-differentiated liposarcoma was characterized by a higher frequency of the following findings compared with lipoma: (1) deep location, (2) irregular shape, (3) large diameter, (4) hyperechogenicity compared to surrounding tissue, and (5) presence of vascularity on Doppler sonography (p < 0.01 each). Notably, hyperechogenicity corresponded to the intermingled sclerosing component within the adipocytic component when sonographic findings were compared with those of pathology.

CONCLUSION

The present study suggests that several sonographic findings including hyperechogenicity and presence of vascularity might be key features for discriminating well-differentiated liposarcoma from lipoma.

Intraoperative ultrasonography-guided surgery for malignant soft tissue tumor

BACKGROUND AND OBJECTIVES

A clear surgical margin is crucial for preventing the recurrence of soft tissue sarcomas (STSs). Recognizing the tumor border is difficult when the STS is impalpable or ill-defined. Ultrasonography (US) is a widely used diagnostic device that can visualize certain tumors intraoperatively. However, its usefulness for intraoperatively assessing STSs is unclear and was investigated here.

METHODS

Our study comprised 19 patients with STSs that were impalpable, ill-defined, or beneath the fascia. All patients underwent intraoperative US (IOUS), with follow-up times ranging from 5 to 103 months (mean, 49 months).

RESULTS

The mean age of the study participants was 56 years (range, 25-83 months). The most common histological diagnosis was undifferentiated pleomorphic sarcoma (UPS) (nine patients). The mean tumor size was 51 mm (range, 7-126 mm). According to the residual tumor classification, 18 tumors were microscopically negative (R0), including seven close to the fascia, and one was microscopically positive (R1). Local recurrence occurred in two cases (both classified as R0). The recurrence-free survival rate was 88.9% in 5 years.

CONCLUSIONS

IOUS-guided surgery is useful for visualizing STSs. Using this technique, STSs can be precisely localized, evaluated, and excised.

A review with an additional case: amelanotic malignant melanoma at mandibular gingiva

The purpose of this review with an additional case is to evaluate the clinical, ultrasonographic and histopathological features of a rare case of Amelanotic Malignant Melanoma (AMM) at mandibular gingiva and to compare our case with other published AMMs at mandibular gingiva. A 52-year-old male patient with no systemic diseases was referred to our clinic with a soft tissue lesion at mandibular gingiva. Ultrasonographic examination was performed and a lesion with malignant features was observed. A periapical radiograph was taken to investigate bone destruction and biopsy was planned. Histopathological examination revealed AMM and a literature search was performed to congregate reports which were indexed in PubMed, ScienceDirect, and ResearchGate. Three AMM cases at mandibular gingiva were found. Doppler Ultrasound examination suggested bone destruction and a 1.8 cm × 0.6 cm soft tissue mass with well-defined borders and increased vascularity. Due to its hypervascularity, depth of invasion and destruction at the bone, the lesion was prediagnosed as a malignancy. Lack of melanin pigmentation caused the large immunohistochemical panel study. The tumour cells showed HMB45 and S100 positivity and they were negative with SMA, Desmin, CK1.3, and CK20. Routine ultrasound examination of all soft tissue lesions is very important for assessing features such as vascularity, bone destruction and depth of invasion to detect malignancy. Melanocytic-associated immunohistochemical markers are crucial for AMM diagnosis.

Accuracy of ultrasound in the characterisation of deep soft tissue masses: a prospective study

PURPOSE

To investigate the accuracy of ultrasound in characterising the type of mass and likelihood of malignancy in deep soft tissue masses.

METHODS

Five hundred seventy-nine deep soft tissue masses were prospectively studied by ultrasound. Masses (n = 137) with prior MRI or CT were not included. Following ultrasound examination, the likely nature of the mass as well as the confidence of the reporting radiologist ('fully confident' versus 'not fully confident') about the ultrasound diagnosis was recorded. Clinical and ultrasound diagnoses were compared with the histological diagnosis which was available in 134 (23%) of the 579 masses.

RESULTS

Compared with histology, clinical and ultrasound accuracy for characterising the type of mass were 47% and 88% respectively when all differential diagnoses were considered. The radiologist was fully confident regarding the type of 436 (75%) of 579 masses and, in this setting, for those cases that could be compared with histology, diagnostic accuracy was 96%. For the remaining masses, where the radiologist was not fully confident, accuracy compared with histology was 58% for the first differential diagnosis and 80% for all differential diagnoses. For identifying malignancy, sensitivity, specificity, and positive and negative predictive value of ultrasound were 97%, 58%, 67%, and 99% respectively. Ultrasound alone was considered sufficient for diagnostic workup in over half of all deep soft tissue masses.

CONCLUSION

Ultrasound is useful at characterising and recognising malignancy in deep soft tissue masses. Provided local practice patterns are favourable, ultrasound may be considered a first-line investigation in the diagnostic workup of deep soft tissue masses.

KEY POINTS

• In three-quarters of cases, one can be fully confident about characterising the nature of deep soft tissue masses on ultrasound and, for those fully confident cases that could be compared with histology, the diagnostic accuracy of ultrasound was 96%. • Ultrasound can correctly recognise nearly all malignant deep soft tissue masses but some benign masses will also be considered possibly malignant. • Ultrasound alone was considered sufficient for imaging workup in over half of deep soft tissue masses.

Accuracy of ultrasound in the characterization of superficial soft tissue tumors: a prospective study

OBJECTIVE

To prospectively evaluate the accuracy of ultrasound in defining the specific nature of superficial soft tissue masses as well as determining malignancy.

MATERIALS AND METHOD

Eight hundred twenty-three superficial soft tissue masses were prospectively evaluated with ultrasound by one of five experienced musculoskeletal radiologists. The radiologist at the time of examination provided one to three specific differential diagnoses and the perceived level of confidence with regard to each diagnosis. Clinical and ultrasound diagnoses were compared with the histological diagnosis to determine accuracy. Tumor malignancy was determined by histology or clinical/imaging follow-up.

RESULTS

Histological correlation was present for 219 (26.6%) of the 823 masses. Compared with histology, the accuracy of clinical and ultrasound examination for determining specific tumor type was 25.6% and 81.2% respectively considering all differential diagnoses provided. Radiologists were "fully confident" with the ultrasound diagnosis in 585 (71.1%) of 823 masses overall. In this setting, when compared with histology, the diagnostic accuracy of ultrasound was 95.5%. When the radiologist was "not fully confident," accuracy was 41.3% for the first differential diagnosis and 60.9% for all differential diagnoses. Diagnostic accuracy improved with increasing radiologist experience. Sensitivity, specificity, positive predictive value, and negative predictive value of ultrasound for identifying malignant tumor were 93.3%, 97.9%, 45.2%, and 99.9% respectively.

CONCLUSIONS

One can be "fully confident" at characterizing over two-thirds of superficial soft tissue masses based on ultrasound appearances and, in this setting, diagnostic accuracy is very high. Ultrasound examination is also highly accurate at discriminating benign from malignant superficial soft tissue masses.

Ultrasonographic findings and diagnosis of omental dedifferentiated liposarcoma: a case report

Liposarcoma is one of the most common types of soft tissue sarcomas and can develop at any site, although omental liposarcoma is extremely rare. Omental liposarcoma has a poor prognosis because the diagnosis is difficult, until it presents as a large tumor causing severe noticeable clinical symptoms. A 51-year-old male with lower abdominal pain was referred to our clinic. Abdominal ultrasonography revealed an ill-defined, solid, heterogeneous, and hypoechoic tumor deep in the lower abdomen. Generally, liposarcomas are hyperechoic, though 20% of liposarcomas present as hypoechoic tumors. This variation might occur depending on the pathological classification. We should consider the possibility of a dedifferentiated component if ultrasonography reveals typical features of soft tissue sarcoma with hypoechoic lesion.

Diagnostic performance of conventional ultrasound and quantitative and qualitative real-time shear wave elastography in musculoskeletal soft tissue tumors

BACKGROUND

To explore the feasibility to identify malignant musculoskeletal soft tissue tumors using real-time shear wave elastography (rtSWE).

METHODS

One hundred fifteen musculoskeletal soft tissue tumors in 92 consecutive patients were examined using both conventional ultrasonography (US) and rtSWE. For each patient, the rtSWE parameters including maximum elasticity (E_max), mean elasticity (E_mean), minimum elasticity (E_min), standard deviation of the elasticity (E_sd), and rtSWE image pattern were obtained. Eighty-one histopathologically confirmed tumors from 73 patients were subjected to analysis.

RESULTS

The 81 lesions included in the study were histopathologically classified as malignant (n = 21) or benign (n = 60). The statistically significant differences between benign and malignant lesions were found in conventional US characters including size, depth, margin, echogenicity, mass texture, and power Doppler signal. Meanwhile, the significant differences were also found in quantitative rtSWE findings including E_max, E_mean, E_min, and E_sd values and in qualitative rtSWE parameter named rtSWE image pattern. Multivariate analysis showed that infiltrative margin (OR, 4.470), and size (OR, 1.046) were independent predictors for malignancy in US findings, while E_sd value (OR, 9.047) was independent predictors for malignancy in quantitative rtSWE parameters. Areas under the ROC curve (Azs) for US features, E_sd value, and rtSWE image pattern were 0.851, 0.795, and 0.792, respectively.

CONCLUSIONS

Conventional US and quantitative and qualitative rtSWE parameters are useful for malignancy prediction of musculoskeletal soft tissue tumors. rtSWE can be used to supplement conventional US to diagnose musculoskeletal soft tissue tumors.

Sonographic Appearances of Liposarcoma: Correlations with Pathologic Subtypes

Liposarcoma is the second most common malignant soft-tissue tumor. This entity is pathologically categorized into 4 subtypes: well-differentiated, myxoid, dedifferentiated and pleomorphic. Although features on magnetic resonance imaging and computed tomography for these 4 subtypes have been reported quite precisely, those on sonography have not been fully investigated. The present study was therefore aimed at clarifying the sonographic appearances of each liposarcoma subtype and assessing correlations with histopathology. The study population was made up of 35 cases, including 21 cases of well-differentiated liposarcoma, 6 cases of myxoid liposarcoma, 6 cases of dedifferentiated liposarcoma and 2 cases of pleomorphic liposarcoma. Compared with the other subtypes, well-differentiated liposarcoma was characterized by the high frequency of the following findings: isoechogenicity, tiny hyperechoic lines and hypovascularity (p < 0.01, in each). Myxoid liposarcomas were characterized by low echogenicity, intermingled with anechoic areas and moderate vascularity (p < 0.01, in each). Dedifferentiated liposarcomas showed a specific biphasic pattern of hyperechoic and hypoechoic areas and hypervascularity (p < 0.01, in each). Pleomorphic liposarcomas showed a specific gyrus-like mixture of hyperechoic and hypoechoic areas (p < 0.01). In conclusion, the present study revealed different characteristics of sonographic appearance among the 4 histopathologic subtypes of liposarcoma.

Preoperative Ultrasonographic Evaluation for Malignancy of Soft-Tissue Sarcoma: A Retrospective Study

Background:

Ultrasonography is useful for distinguishing between benign and malignant soft-tissue tumors. However, no study has focused on its usefulness in the differential diagnosis between low-grade and high-grade soft-tissue sarcomas. We conducted a retrospective study to determine the usefulness of the parameters of ultrasonograph and to develop a practical scoring system for distinguishing between high-grade and low-grade sarcomas.

Methods:

Twenty-two cases of low-grade and 43 cases of high-grade malignant soft-tissue sarcoma were enrolled. Ultrasonography parameters including the longest diameter, depth of the tumor, echogenicity, tumor margin, and vascularity defined according to Giovagnorio’s criteria were analyzed as factors to distinguish between the two types of sarcoma. Significant factors were entered into a multivariate model to define the scores for distinction according to the odds ratio. The usefulness of the score was analyzed via receiver operating characteristic analyses.

Results:

In univariate analysis, tumor margin, echogenicity, and vascularity were significantly different between low- and high-grade sarcomas. In the multivariate regression model, the odds ratio for high-grade vs. low-grade sarcoma was 8.8 for tumor margin, 69 for echogenicity, and 8.3 for vascularity. Scores for the risk factors were defined as follows: 1, ill-defined margin; 2, hypoechoic echogenicity; and 1, type IV in Giovagnorio’s criteria. The sum of each score was confirmed by receiver operating characteristic analysis. The area under the curve was 0.95, with a cut-off score of 3, indicating that the scoring system was useful.

Conclusion:

The ultrasonography parameters of tumor margin, echogenicity, and vascularity are useful for distinguishing between low- and high-grade sarcomas.