Accuracy of sonographic diagnosis of superficial masses

Ultrasound of palpable lesions: a pictorial review

Ultrasound (US) is the imaging modality of choice for evaluation of superficial palpable lesions. A large proportion of these lesions have characteristic sonographic appearance and can be confidently diagnosed with US without the need for biopsy or other intervention. The Society of Radiologists in Ultrasound (SRU) recently published a Consensus Conference Statement on superficial soft tissue masses. The goal of this manuscript is (a) to serve as a sonographic pictorial review for palpable lesions based on the SRU statement, (b) present the typical sonographic features of palpable lesions that can be confidently diagnosed with US, and (c) provide an overview of other palpable lesions with a framework to interpret the US studies and advise on appropriate further management.

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.

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.

Deep Learning-Based Evaluation of Ultrasound Images for Benign Skin Tumors

In this study, a combined convolutional neural network for the diagnosis of three benign skin tumors was designed, and its effectiveness was verified through quantitative and statistical analysis. To this end, 698 sonographic images were taken and diagnosed at the Department of Dermatology at Severance Hospital in Seoul, Korea, between 10 November 2017 and 17 January 2020. Through an empirical process, a convolutional neural network combining two structures, which consist of a residual structure and an attention-gated structure, was designed. Five-fold cross-validation was applied, and the train set for each fold was augmented by the Fast AutoAugment technique. As a result of training, for three benign skin tumors, an average accuracy of 95.87%, an average sensitivity of 90.10%, and an average specificity of 96.23% were derived. Also, through statistical analysis using a class activation map and physicians' findings, it was found that the judgment criteria of physicians and the trained combined convolutional neural network were similar. This study suggests that the model designed and trained in this study can be a diagnostic aid to assist physicians and enable more efficient and accurate diagnoses.

Non-Vascular Considerations When Interpreting Extremity Arterial and Venous Examinations

Peripheral arterial and venous examinations are performed regularly in vascular labs and interpreted by physicians of different specialities. Many vascular examinations have nonvascular pathology that is either inadvertently imaged by the sonographer or imaged with intent as it relates to patient's symptoms. It is prudent for every reader of vascular studies to be acquainted with the sonographic appearance of these non-vascular lesions to enable appropriate and optimal interpretation that has a direct bearing on patient's clinical care. Our review includes a discussion of the nonvascular pathologies like lymph nodes, soft tissue edema, soft tissue fluid collections, musculotendinous injuries, soft tissue masses, and joint and bursal pathologies that may be encountered during interpretation of vascular exams. The pictorial essay includes a discussion of their sonographic appearances and pitfalls in interpretation. Multiple illustrative examples and sonographic images of the non-vascular pathologies found during interpretation of vascular studies have been utilized to highlight their appearances.

Ultrasonography of Superficial Soft-Tissue Masses: Society of Radiologists in Ultrasound Consensus Conference Statement

The Society of Radiologists in Ultrasound convened a panel of specialists from radiology, orthopedic surgery, and pathology to arrive at a consensus regarding the management of superficial soft-tissue masses imaged with US. The recommendations in this statement are based on analysis of current literature and common practice strategies. This statement reviews and illustrates the US features of common superficial soft-tissue lesions that may manifest as a soft-tissue mass and suggests guidelines for subsequent management.

Case Series: Superficial Sonography in Urgent Care

Sonography is an essential imaging modality, known for its real-time capabilities, relative low cost, and multiple diagnostic applications. Although there are protocols which are well-established for specific examinations, there are not clear guidelines for sonographic examinations of soft tissues. Many sonographers have to establish their own imaging protocols when completing a soft tissue examination. This case series details five soft tissue examinations that represent just a few of the clinical requests generated in an Urgent Care (UC) facility. Since UC usage has increased over the past several years, it appears likely that any sonographer working in such outpatient settings will benefit from as much exposure to soft tissue examinations as possible.

Artificial Intelligence for Classification of Soft-Tissue Masses at US

Purpose

To train convolutional neural network (CNN) models to classify benign and malignant soft-tissue masses at US and to differentiate three commonly observed benign masses.

Materials and Methods

In this retrospective study, US images obtained between May 2010 and June 2019 from 419 patients (mean age, 52 years ± 18 [standard deviation]; 250 women) with histologic diagnosis confirmed at biopsy or surgical excision (n = 227) or masses that demonstrated imaging characteristics of lipoma, benign peripheral nerve sheath tumor, and vascular malformation (n = 192) were included. Images in patients with a histologic diagnosis (n = 227) were used to train and evaluate a CNN model to distinguish malignant and benign lesions. Twenty percent of cases were withheld as a test dataset, and the remaining cases were used to train the model with a 75%-25% training-validation split and fourfold cross-validation. Performance of the model was compared with retrospective interpretation of the same dataset by two experienced musculoskeletal radiologists, blinded to clinical history. A second group of US images from 275 of the 419 patients containing the three common benign masses was used to train and evaluate a separate model to differentiate between the masses. The models were trained on the Keras machine learning platform (version 2.3.1), with a modified pretrained VGG16 network. Performance metrics of the model and of the radiologists were compared by using the McNemar test, and 95% CIs for performance metrics were estimated by using the Clopper-Pearson method (accuracy, recall, specificity, and precision) and the DeLong method (area under the receiver operating characteristic curve).

Results

The model trained to classify malignant and benign masses demonstrated an accuracy of 79% (95% CI: 68, 88) on the test data, with an area under the receiver operating characteristic curve of 0.91 (95% CI: 0.84, 0.98), matching the performance of two expert readers. Performance of the model distinguishing three benign masses was lower, with an accuracy of 71% (95% CI: 61, 80) on the test data.

Conclusion

The trained CNN was capable of differentiating between benign and malignant soft-tissue masses depicted on US images, with performance matching that of two experienced musculoskeletal radiologists.© RSNA, 2020.

Small Subcutaneous Soft Tissue Tumors (<5 cm) Can Be Sarcomas and Contrast-Enhanced Ultrasound (CEUS) Is Useful to Identify Potentially Malignant Masses

Subcutaneous masses smaller than 5 cm can be malignant, in contrast with the international guidelines. Ultrasound (US) and magnetic resonance imaging (MRI) are useful to distinguish a potentially malignant mass from the numerous benign soft tissue (ST) lesions. Contrast-enhanced ultrasound (CEUS) was applied in ST tumors, without distinguishing the subcutaneous from the deep lesions. We evaluated CEUS and MRI accuracy in comparison to histology in differentiating malignant from nonmalignant superficial ST masses, 50% smaller than 5 cm. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) with their 95% confidence intervals (CI) were calculated. Of malignant cases, 44.4% measured ≤5 cm. At univariate analysis, no statistically significant differences emerged between benign and malignant tumors in relation with clinical characteristics, except for relationship with the deep fascia (p = 0.048). MRI accuracy: sensitivity 52.8% (CI 37.0, 68.0), specificity 74.1% (CI 55.3, 86.8), PPV 73.1% (CI 53.9, 86.3), and NPV 54.1% (CI 38.4, 69.0). CEUS accuracy: sensitivity 75% (CI 58.9, 86.3), specificity 37% (CI 21.5, 55.8), PPV 61.4% (CI 46.6, 74.3), and NPV 52.6% (CI 31.7, 72.7). CEUS showed a sensitivity higher than MRI, whereas PPV and NPV were comparable. Also, masses measuring less than 5 cm can be malignant and referral criteria for centralization could be revised.

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.

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.

Ultrasound of Soft Tissue Masses and Fluid Collections

Soft tissue masses and fluid collections are frequently encountered in sonographic practice, either as principal indication for diagnostic examination or as an incidental finding during an examination performed for other indications. Sonography is a good first-line imaging modality for evaluation of superficial masses and fluid collections, but requires meticulous attention to technique to avoid diagnostic pitfalls. Although many superficial masses are diagnosed with ultrasound, there are several potential diagnostic challenges, including differentiating hematomas from sarcomas. This article provides an image-rich review of the sonographic features of common soft tissue masses, with emphasis on practical tips to accurately recognize important pathology.

An intra-oral approach to facial skin lumps-a move towards scarless surgery

INTRODUCTION

The aim of surgical management of benign facial skin lumps is to remove the lesion in its entirety, with minimal damage to adjacent tissue structures, while maintaining facial aesthetics. A method to achieve these goals is to remove peri-oral lesions in the labial and buccal zones via an intra-oral approach. We report an extended cases series of facial skin lumps that were excised using an intra-oral approach.

METHODS

A retrospective analysis was performed on all patients who underwent excisions of benign cutaneous lesions on the face via an intra-oral approach. Patient demographics, indication for surgery and complications were noted.

RESULTS

Forty-seven lesions were excised over a 15-year period. Indications for surgery included benign lesion with minimal skin involvement, risks of keloid/scar hypertrophy and cosmetic factors. Lesions were predominantly epidermoid cysts and lipomas. Mean follow-up was 2.9 years with a 6.4% recurrence rate and 2.1% rate of haematoma and transient facial nerve weakness.

DISCUSSION

There are established techniques to remove facial skin lumps. We believe that in selected cases, an intra-oral approach to such lesions, particularly in cases with high risk of scar pathology or where there is strong patient preference, may be an important tool in the oral and maxillofacial surgeon's armamentarium.

Removal of Benign Superficial Masses Using the TriVex System: Preliminary Clinical Results

BACKGROUND AND OBJECTIVE

Transilluminated powered phlebectomy using the TriVex system is a new procedure for minimally invasive varicose vein surgery. We used the TriVex system for the removal of benign superficial subcutaneous soft tissue masses, and we also achieved satisfactory clinical effects. The objective of this study was to explore the feasibility, benefits, and technique-related complications of using the TriVex system for the removal of benign superficial masses as a novel and minimally invasive surgical technique.

METHOD

Between January 2010 and August 2016, 452 patients with benign superficial soft tissue masses underwent surgical removal of masses using the TriVex II system in our department. The surgical complications, postoperative cosmetic outcome, and personal satisfaction were reviewed at a mean follow-up of 24 months.

RESULTS

The TriVex procedure was successfully completed in all patients using only local tumescent anesthesia without any technical problem and serious complications. The mean operation duration was 8.5 minutes, and the average blood loss was 5 mL. Surgical complications were observed in 69 cases (15.3%) of subcutaneous ecchymosis, 34 cases (7.5%) of skin perforation, 14 cases (3.1%) of subcutaneous hematoma, 13 cases (2.9%) of wound infection, and 7 cases (1.5%) of induration of operation area. Eleven patients (2.4%) showed recurrence during the follow-up and were cured by reoperation by the TriVex system. Overall, the majority of patients (N = 436, 96.5%) were very satisfied or satisfied with the outcome.

CONCLUSION

The TriVex procedure for the removal of benign superficial masses is simple, safe, and effective with advantages of short operation time, small incisions, and good cosmetic outcome, which is predicted as a new minimally invasive surgery of superficial masses.

The Predictive Value of Ultrasound Scanning in Certain Hand and Wrist Conditions

Background: Fast and accurate diagnosis of conditions of the hand and wrist is essential in guiding management. We aimed to analyse the predictive value of ultrasound in identifying different pathologies in the hand and wrist by correlating pre-operative ultrasound findings with per-operative surgical findings.

Methods: We retrospectively reviewed the case notes of all patients under the care of the senior author on whom a hand/wrist ultrasound had been performed between January 2007–May 2013. Of these only patients who proceeded to surgery were included as this was the correlating endpoint. Positive and negative predictive values (PPV/NPV) and sensitivity and specificity were calculated for ultrasound in identifying (i) post-repair complete tendon ruptures (versus intact repairs with scar adherence), (ii) ganglionic cysts, (iii) soft tissue masses and (iv) nerve injuries.

Results: Of 70 patients who underwent ultrasound, 36 proceeded to surgery. Fifteen patients were post traumatic and the remaining 21 were elective presentations. The median age was 38 (range 14–87) with a 1.25:1 male to female ratio. All results had a 95% confidence interval. Ultrasound had a 100% PPV for identifying post-repair complete tendon ruptures and for ganglionic cysts (sensitivities 75% and 87% respectively). Of our 6 soft tissue masses ultrasound also showed a 100% PPV. For the two nerve injury patients, PPV was 100%.

Conclusions: Our study shows that ultrasound is diagnostic for post-repair tendon ruptures and ganglionic cysts, and shows promising results for benign soft tissue masses and nerve injuries. We propose the use of ultrasound as an extension to physical examination in a dynamic clinic setting.

The diagnostic accuracy of ultrasonography for soft tissue lipomas: a systematic review

Background

Ultrasound has been used in the diagnosis of soft-tissue lesions for well over a decade. Lipomas are the most common, benign, soft-tissue tumor and comprise adipose tissue. The sensitivity and specificity of diagnosing lipomas on ultrasound vary greatly in the literature.

Purpose

To perform a systematic review on ultrasonography in soft-tissue lipomas to better ascertain the true diagnostic value of this test.

Material and Methods

A systematic review of the diagnostic value of ultrasound in lipomas was performed where possible in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search of the literature was conducted using several well-known databases Scopus®, PubMed®, Ovid® Medline, and Web of Science®.

Results

A total of 455 articles were identified in the initial literature search. Six papers were included in the final systematic review, which revealed an overall sensitivity and specificity of 86.87% (95% confidence interval [CI] = 82.14–90.73) and 95.95% (95% CI = 93.75–97.54), respectively.

Conclusion

Ultrasound is a useful tool in the diagnosis of superficial lipomas with good sensitivity and even better specificity and should continue to be the first line investigation in such cases.

Cranium-Penetrating Mass Detected by Ultrasound Expedited Management of Langerhans Cell Histiocytosis

A 6-year-old boy presented to the pediatric emergency department with a unilateral 5 × 3-cm superficial mass on the postauricular region growing for 1 month. Point-of-care ultrasound was used to evaluate the mass, which revealed a complex cystic mass penetrating the temporal bone. After confirmatory magnetic resonance imaging, the patient was transferred for neurosurgical evaluation, and the tumor was excised. Pathology revealed Langerhans cell histiocytosis.

2-D and 3-D Ultrasound for Tumor Volume Analysis: A Prospective Study

Ultrasound (US) allows real-time tumor assessment. We evaluated the volumetric limits of 2-D and 3-D US, compared with magnetic resonance imaging (MRI), with a prospective institutional review board-approved clinical evaluation of US-to-MRI volumetric correlation. US images of pre- and post-neoadjuvant breast cancers were obtained. Volume discrepancy was evaluated with the non-parametric Wilcoxon signed-rank test. Expected inter-observer variability <14% was evaluated as relative paired difference (RPD); clinical relevance was gauged with the volumetric standard error of the mean (SEM). For 42 patients, 133 of 170 US examinations were evaluable. For tumors ≤20 cm³, both highly correlated to MRI with RPD within inter-observer variability and Pearson's correlation up to 0.86 (0.80 before and 0.86 after neoadjuvant chemotherapy, respectively). Lesions 20-40 cm³ had US-to-MRI discrepancy within inter-observer variability for 2-D (RPD: 13%), but not 3-D (RPD: 27%) US (SEM: 1.47 cm³ for 2-D, SEM: 2.28 cm³ for 3-D), suggesting clinical utility. Tumors >40 cm³ correlated poorly. Tumor volumes ≤20 cm³ exhibited a good correlation to MRI. Studies of clinical applications are warranted.

Fat-containing soft-tissue masses in children

The diagnosis of soft-tissue masses in children can be difficult because of the frequently nonspecific clinical and imaging characteristics of these lesions. However key findings on imaging can aid in diagnosis. The identification of macroscopic fat within a soft-tissue mass narrows the differential diagnosis considerably and suggests a high likelihood of a benign etiology in children. Fat can be difficult to detect with sonography because of the variable appearance of fat using this modality. Fat is easier to recognize using MRI, particularly with the aid of fat-suppression techniques. Although a large portion of fat-containing masses in children are adipocytic tumors, a variety of other tumors and mass-like conditions that contain fat should be considered by the radiologist confronted with a fat-containing mass in a child. In this article we review the sonographic and MRI findings in the most relevant fat-containing soft-tissue masses in the pediatric age group, including adipocytic tumors (lipoma, angiolipoma, lipomatosis, lipoblastoma, lipomatosis of nerve, and liposarcoma); fibroblastic/myofibroblastic tumors (fibrous hamartoma of infancy and lipofibromatosis); vascular anomalies (involuting hemangioma, intramuscular capillary hemangioma, phosphate and tensin homologue (PTEN) hamartoma of soft tissue, fibro-adipose vascular anomaly), and other miscellaneous entities, such as fat necrosis and epigastric hernia.

Sonographic Differentiation Between Angiolipomas and Superficial Lipomas

OBJECTIVES

The purpose of this study was to compare the sonographic findings of angio lipomas with those of superficial lipomas.

METHODS

Preoperative sonograms of 26 angiolipomas from 18 patients and 47 superficial lipomas from 43 patients that were confirmed by biopsy were reviewed retrospectively. The echo texture, echogenicity, internal echogenic stranding, vascularity, visualization of lateral and superficial-deep tumor capsules, shape, and tumor length, width, and length-to-width ratio were evaluated and compared between angiolipomas and superficial lipomas.

RESULTS

Angiolipomas frequently appeared as heterogeneous (19 of 26 [73.1%]), hyperechoic (23 of 26 [88.5%]), and ovoid (17 of 26 [65.4%]) masses with lesser visualized lateral tumor capsules (6 of 26 [23.1%]), whereas superficial lipomas appeared as homogeneous (36 of 47 [76.6%]), isoechoic (35 of 47 [74.5%]), and spindle-shaped (23 of 47 [48.9%]) masses with well-visualized lateral capsules (33 of 47 [70.2%]), and the differences were statistically significant (P < .001). Vascularity was seen in 4 angiolipomas (16.7%) and in no superficial lipomas (0%). The mean length and width ± SD of angiolipomas (2.2 ± 1.02 and 0.6 ± 0.27 cm, respectively) were smaller than those of superficial lipomas (4.2 ± 1.52 and 1.1 ± 0.51 cm), with statistical significance (P< .001). The other sonographic findings did not reveal statistically significant differences between the tumor types.

CONCLUSIONS

Sonography might help differentiate angiolipomas from superficial lipomas.

Twinkle artefact in the ultrasound diagnosis of superficial epidermoid cysts

AIM

The aim of the study was to evaluate whether the twinkle artefact is a valuable feature in the sonographic diagnosis of superficial epidermoid cysts.

MATERIALS AND METHODS

A retrospective search was undertaken of our institution's Radiology Information System and pathology database to identify cases of superficial masses showing the twinkle artefact that proceeded to surgical excision.

RESULTS

Eighteen superficial masses demonstrating the twinkle artefact were identified that were submitted for pathological analysis. Of these, 17 were confirmed to represent epidermoid cysts and only 1 case had an alternative diagnosis (proliferating trichilemmal cyst).

CONCLUSION

The presence of the twinkle artefact appears to be a specific and valuable ancillary sonographic feature for the diagnosis of superficial epidermoid cysts.

Sonography of Abdominal Wall Masses and Masslike Lesions: Correlation With Computed Tomography and Magnetic Resonance Imaging

Sonography is usually regarded as a first-line imaging modality for masses and masslike lesions in the abdominal wall. A dynamic study focusing on a painful area or palpable mass and the possibility of ultrasound-guided aspiration or biopsy are the major advantages of sonography. On the other hand, cross-sectional imaging clearly shows anatomy of the abdominal wall; thereby, it is valuable for diagnosing and evaluating the extent of diseases. Cross-sectional imaging can help differentiate neoplastic lesions from non-neoplastic lesions. This pictorial essay focuses on sonographic findings of abdominal wall lesions compared with computed tomographic and magnetic resonance imaging findings.

The diagnostic value of ultrasonography with 5-15-MHz probes in benign subcutaneous lesions

BACKGROUND

Ultrasonography (US) has recently proved to be useful in diagnostic dermatology. It is convenient to use, completely safe, and provides valuable information.

OBJECTIVE

This study was performed to compare the diagnostic accuracy of US with that of clinical diagnosis in patients with benign subcutaneous lesions.

METHODS

We retrospectively examined data for 100 patients with benign subcutaneous lesions who were diagnosed with US and either biopsy or surgery at Seoul National University Boramae Hospital between January 2010 and May 2013.

RESULTS

Ultrasonography significantly increased the diagnostic yield of benign subcuta-neous lesions (after physical examination [PE], 52.0%; after US, 82.0%; P < 0.005). Rates of sensitivity and specificity for the diagnosis of lipoma were 61.5 and 92.0%, respectively, after PE, and 100 and 100%, respectively, after US. Rates of sensitivity and specificity for the diagnosis of epidermal cysts were 69.4 and 78.4%, respectively, after PE, and 91.8 and 92.2%, respectively, after US. Additionally, rates of sensitivity and specificity for pilomatrixoma were 12.5 and 98.9%, respectively, after PE, and 75.0 and 100%, respectively, after US. Although the accuracy of diagnosis of vascular anomalies and nerve sheath tumors was increased after US, the difference was not significant (vascular anomalies: 40.0% after PE and 80.0% after US; nerve sheath tumors: 28.6% after PE and 42.9% after US).

CONCLUSIONS

This study suggests that US is a simple and reliable tool that can aid the diagnosis of benign subcutaneous lesions.