Role of ultrasound in the diagnosis of primary and recurrent dermatofibrosarcoma protuberans

The Usefulness of Ultrasonography for Supporting the Differentiation, Diagnosis, and Treatment of Atypical Fibroxanthoma and Pleomorphic Dermal Sarcoma

Atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) are rare histomorphological variants of a disease spectrum. After ruling out other tumor entities by immunohistochemistry, PDS can be differentiated from AFX by infiltration into the subcutis, while AFX remains confined to the dermis. The therapeutic approach is more aggressive in PDS as it can potentially metastasize. We assessed the usefulness of preoperative sonography in differentiating between the two tumor entities by identifying a potential subcutaneous infiltration. In our patients (n = 13), preoperative sonography identified and differentiated AFX and PDS with 100% accuracy and even changed the initial histological suspicion of AFX to PDS in 3 cases (23%), which was confirmed after tumor resection. Preoperative sonography of these tumors could strengthen the clinical diagnosis, avoid a delay in therapy initiation and improve patient counseling. While for AFX, micrographic-controlled surgery suffices, for PDS, resection with 2 cm safety margins and lymph node sonography to rule out lymphonodal involvement is necessary. Hence, ultrasonography can improve clinical practice by providing helpful information for dermatosurgeons, which cannot be obtained during clinical examination.

High-frequency ultrasound-assisted Mohs micrographic surgery for the treatment of dermatofibrosarcoma protuberans

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a superficial sarcoma characterized by infiltrative growth with tentacle-like borders. Mohs micrographic surgery (MMS) is the preferred treatment option for DFSP. However, the imprecise boundary localization in MMS leads to an increased number of Mohs layers required and a longer surgery time. High-frequency ultrasound has excellent tissue recognition capability for DFSP, allowing for precise boundary marking.

MATERIALS AND METHODS

In this study, we retrospectively analyzed 14 cases of DFSP treated with MMS using preoperative ultrasound localization and three-dimensional reconstruction at Xiangya Hospital over the past 5 years. We also reviewed previous studies on MMS for DFSP treatment.

RESULTS

It was found that the average number of Mohs layers for patients after preoperative ultrasound localization was 1.57, ranging from 1 to 3, which was less than the previously reported 1.86 layers, ranging from 1 to 12. This effectively reduced the number of Mohs layers required.

CONCLUSIONS

By utilizing preoperative high-frequency ultrasound to determine the boundaries and depth of DFSP, the number of Mohs layers can be effectively reduced, leading to less workload for pathological examination, shorter operation time, and reduced surgical risks for patients. Ultrasound imaging data can be used for three-dimensional reconstruction, enabling less experienced Mohs surgeons to have a visual understanding of the morphology and extent of infiltration of the lesions. This aids in developing optimal surgical plans, smoothing the learning curve, and promoting the wider adoption of MMS.

Diagnostic accuracy of high-frequency ultrasound for cutaneous neoplasms: a narrative review of the literature

High-frequency ultrasound has been used to visualize depth and vascularization of cutaneous neoplasms, but little has been synthesized as a review for a robust level of evidence about the diagnostic accuracy of high-frequency ultrasound in dermatology. A narrative review of the PubMed database was performed to establish the correlation between ultrasound findings and histopathologic/dermoscopic findings for cutaneous neoplasms. Articles were divided into the following four categories: melanocytic, keratinocytic/epidermal, appendageal, and soft tissue/neural neoplasms. Review of the literature revealed that ultrasound findings and histopathology findings were strongly correlated regarding the depth of a cutaneous neoplasm. Morphological characteristics were correlated primarily in soft tissue/neural neoplasms. Overall, there is a paucity of literature on the correlation between high-frequency ultrasound and histopathology of cutaneous neoplasms. Further studies are needed to investigate this correlation in various dermatologic conditions.

Conventional and contrast-enhanced ultrasound in the differential diagnosis of recurrent dermatofibrosarcoma protuberans and postoperative scar

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) has a high recurrence rate after resection. Because of the lack of specific manifestations, recurrent DFSP is easily misdiagnosed as post-resection scar. A few series have reported ultrasound findings of recurrent DFSP; moreover, the usefulness of contrast-enhanced ultrasound in differentiating recurrent DFSP has not been studied.

OBJECTIVE

We investigated conventional and contrast-enhanced ultrasound in the differential diagnosis of recurrent DFSP and post-resection scar.

METHODS

We retrospectively evaluated the findings of conventional and contrast-enhanced ultrasound in 34 cases of recurrent DFSP and 38 postoperative scars examined between January 2018 and December 2022.

RESULTS

The depth and vascular density of recurrent DFSP were greater than those of postoperative scars (P < 0.05). On gray-scale ultrasound, recurrent DFSP lesions were more commonly irregular, heterogeneous, and hypoechoic, with finger-like projections and ill-defined borders. Postoperative scar was more likely to appear as hypoechoic and homogeneous with well-defined borders (P < 0.05). On color Doppler ultrasound, recurrent DFSP was more likely to feature rich arterial and venous blood flow, and postoperative scar was more likely to display poor blood flow (P < 0.05). On contrast-enhanced ultrasound, recurrent DFSP was more likely to feature heterogeneous hyper-enhancement, and postoperative scar was more likely to display homogeneous iso-enhancement (P < 0.05). Recurrent DFSP presented a higher peak and sharpness than postoperative scar (P < 0.05).

CONCLUSION

Conventional and contrast-enhanced ultrasound produced distinct features of recurrent DFSP and post-resection scar, which could improve the accuracy of differential diagnosis.

Ultrasound Assessment of Skin Tumors Local Recurrence

Skin cancer may recur at or around the surgical site despite wide excisions. Prompt clinical and sonographic detection of local recurrence is important since subjects with relapsing melanomas or nonmelanoma malignancies can be managed efficaciously, with a relevant impact on morbidity and survival. Ultrasound is being employed with increasing frequency in the assessment of skin tumors, but most of the published articles relate to initial pretherapeutic diagnosis and staging. This review aims to offer an illustrated guide to the sonographic evaluation of locally recurring skin cancer. We introduce the topic, then we provide some sonographic tips for patient follow-up, then we describe the ultrasound findings in case of local recurrence, illustrating the main mimickers, and finally, we mention the role of ultrasound in guiding diagnostic and therapeutic percutaneous procedures.

Dermatofibrosarcoma protuberans challenges: a case series and review of the literature

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare variant of skin sarcoma which is characterized by proliferation of spindle cells in a storiform pattern. Although it is mostly benign in its primary stages, it can cause a high burden of morbidity unless it is thoroughly excised.

CASE PRESENTATION

Here, we review six cases of DFSP which were characterized by skin lesions in various parts of the body. Patients were from 26 to 51 years old; four were Asian men and two were Asian women. Wide surgical excision was performed for all these patients and no extra treatment was considered. Samples were studied by hematoxylin and eosin (H&E) staining and immunohistochemical (IHC) tests. Only one of our patients experienced recurrence after the initial surgery.

CONCLUSION

Determining the best surgical method is still a dilemma in the treatment of DFSP lesions. There are numerous studies to prove the efficacy of various surgical interventions. Although DFSP is not commonly known as a malignant skin lesion, delay in treatment will have a catastrophic impact on patients' lives. Thus, applying an in-time surgical method (wide local excision in our cases) in treating DFSP is crucial in preventing recurrence as well as decreasing the morbidity burden of DFSP.

Multimodal ultrasound for preoperative evaluation of dermatofibrosarcoma protuberans: a series of 40 cases

Background

Dermatofibrosarcoma protuberans (DFSP) is a rare, low to intermediate-grade sarcoma, which needs imaging examination. Small series of ultrasound findings in DFSP have been published; however, the usefulness of elastography and contrast-enhanced ultrasound (CEUS) in DFSP has not been studied. We aim to study multimodal ultrasound findings and report the correlation between imagings and tiny extension in DFSP for preoperative evaluation.

Methods

Two-D ultrasound, 3-D color ultrasound, elastography, and CEUS findings were retrospectively evaluated. Forty histopathologically confirmed DFSPs were studied.

Results

On 2-D ultrasound, 26(65%) appeared as mostly hypoechoic lesions with occasional hyperechoic dots within the tumor matrix and lobulated lateral borders. Eight (20%) lesions were multilayered. Ninety-five percent of lesions showed increased vascularity. On 3-D ultrasound, DFSPs showed branch-shaped, striped, and wrapped color patterns. Power Doppler showed mainly artery of a moderate arterial peak systolic blood flow and low resistance index. DFSP is hard on elastography. On CEUS, DFSPs showed a long peak time, low peak and a small amount of perfusion around the tumor, 73.7% (14/19) of lesions showed a heterogeneous contrast enhancement and 89.5% (17/19) of lesions showed hyper-enhancement. CEUS showed better concordance than US with histology on the maximum diameter and depth (P < 0.05).

Conclusions

Multimodal ultrasound showed significant characteristics in DFSP, which would improve diagnostic accuracy. CEUS could be an effective tool to determine tiny tumor extension.

Hybridtumor eines Riesenzellfibroblastoms und eines Dermatofibrosarcoma protuberans

Wir berichten über ein zum Zeitpunkt der Erstmanifestation 10 Monate altes Kind mit einem Hybridtumor aus Riesenzellfibroblastom (RZFB) und Dermatofibrosarkoma protuberans (DFSP). Das RZFB ist ein seltener Tumor, der mit dem DFSP die Translokation (t17;22) (q22;13) und immunphänotypische Eigenschaften teilt und daher von seinen Erstbeschreibern als kindliche Form des DFSP eingeordnet wurde. Das RZFB hat mit einer Kombination aus Spindelzellproliferaten, häufig hypozellulären Arealen mit kollagenfaserreichem oder myxoidem Stroma, sinusoid-artigen pseudovaskulären Aufweitungen zwischen den Kollagenfasern, die von multinukleären Riesenzellen umsäumt werden, jedoch ein ihm eigenes histologisches Bild. Das RZFB, das sich klinisch als langsam wachsende, i.d.R. schmerzlose Schwellung manifestiert, tritt präferentiell im Kindesalter auf. Das mittlere Erkrankungsalter liegt bei 6 Jahren. Die Therapie der Wahl ist die Exzision mit einem ausreichenden Sicherheitsabstand. Unsere junge Patientin zeigt ein Jahr nach Exzision mit 2 cm Sicherheitsabstand einen rezidivfreien Verlauf.

Breast Imaging Findings in Dermatofibrosarcoma Protuberans: A Case Report and Review of Literature

Dermatofibrosarcoma protuberans (DFSP) is a rare, indolent, cutaneous sarcoma originating in the dermis, and although nearly half of cases occur on the trunk, DFSP of the breast is exceedingly rare, and imaging findings may resemble primary breast neoplasms. In this case report, a previously healthy, middle-aged female patient presented to the clinic with the complaint of abnormal growth in her left breast, which had been gradually increasing in size over the course of four years. Imaging of the left breast demonstrated a large, exophytic, partially intradermal mass with internal vascularity, raising concern for a primary breast neoplasm. Ultrasound-guided core needle biopsy revealed a diagnosis of DFSP. She underwent successful left skin- and nipple-sparing mastectomy with complete resection of the mass with negative margins confirmed on surgical pathology. Recognizing key features of DFSP on conventional breast imaging modalities, such as mammography and ultrasound, can be helpful in differentiating DFSP from primary breast neoplasms, but imaging findings alone may be nonspecific and biopsy is necessary for a definitive diagnosis. On mammography, DFSP typically presents as an exophytic, gently lobulated, non-calcified, and circumscribed mass. On sonographic examination, DFSP appears as a circumscribed, parallel-oriented mass that is hypoechoic relative to the surrounding fat, with intervening echogenic bands, posterior acoustic enhancement, and intralesional hypervascularity visualized on color Doppler. Although DFSP is slow-growing with a low incidence of metastatic disease, it has a high local recurrence rate and aggressive local resection is necessary to minimize the chance of recurrence.

Sun Sign in the Ultrasound Diagnosis and Activity Assessment of Morphea

Morphea, a localized form of scleroderma, is a chronic inflammatory autoimmune disease of the skin. Color Doppler Ultrasound has been reported as a reliable tool to assess the activity of the disease. With histologically confirmed cases, this case series describes a new ultrasound sign consisting of a hyperechoic halo surrounding superficial subcutaneous veins of the extremities in transverse view, named the sun sign. This sign can help diagnose morphea in the inflammatory phase and correlate in pathology with perivascular infiltrates surrounding superficial subcutaneous veins.

Malignant Superficial Mesenchymal Tumors in Children

Malignant superficial mesenchymal tumors are a very diverse group of neoplasms with few clinical and radiological discriminatory factors. Hence, some of these cancers are rarely suspected based on clinical and radiological grounds, others may be easily misdiagnosed, and the histological analysis of a biopsy or resection is central in the diagnostic process. In children, the age at presentation is a major element of the differential diagnosis. Some tumors have a very distinct epidemiology, while others may be seen at any age. More recently, the advances in molecular biology have greatly improved the diagnosis of mesenchymal tumors and new entities are still being described. In the present review, we provide an overview of the diversity of malignant superficial mesenchymal tumors in children, including new and/or rare entities. We discuss the important diagnostic features, be they clinical, histological, or molecular. Special attention was given to the genetic features of these tumors, particularly when they were helpful for the diagnosis or treatment.