Usefulness of ultrasound in dermatofibrosarcoma protuberans and correlation with histopathological findings: A series of 30 cases

Advances in non-invasive imaging for dermatofibrosarcoma protuberans: A review

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma characterized by an asymmetric, infiltrative growth pattern and a high risk of local recurrence. This study aims to evaluate the effectiveness of various imaging modalities in the assessment and management of DFSP. Nine imaging modalities were reviewed including: Ultrasound (US), High-Frequency Doppler Ultrasound (HFUS), Computed tomography (CT), Positron emission tomography-computed tomography (PET-CT), and Magnetic Resonance Imaging (MRI), High-resolution-MRI (HR-MRI), Magnetic Resonance Spectroscopy (MRS), Optical Coherence Tomography (OCT), and Dermatoscopy. Imaging is mainly used for preoperative assessment and surgical planning, not routine diagnosis. US is effective for initial evaluations, demonstrating superior ability in detecting muscle invasion and defining tumour boundaries (sensitivity - 81.8%, specificity - 100%). MRI is valuable for preoperative evaluation, surgical planning, and monitoring DFSP recurrence. It more accurately assesses tumour depth than palpation, with a sensitivity of 67% and specificity of 100%, but was inferior when compared to US. CT is utilized in cases of suspected bone involvement or pulmonary metastasis. For advanced or recurrent DFSP, PET-CT helps manage treatment responses and imatinib therapy. Emerging technologies like MRS and OCT show potential in improving diagnostic accuracy and defining surgical margins, though more data are needed. US, MRI, and CT are the primary imaging modalities for DFSP. Emerging technologies like HR-MRI, PET-CT, MRS, and OCT hold promise for refining diagnostic and management strategies. Integrating multiple technologies could enhance management, particularly in atypical or aggressive cases. Further studies are required to refine imaging protocols and improve DFSP outcomes.

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.

Integrating vascularity into the pattern classification of pilomatricomas on ultrasound provides a more competent approach for discriminative evaluation

BACKGROUND

Pilomatricoma has various manifestations on color Doppler ultrasound, and a differential diagnosis is challenging. The objective of this study was to investigate which characteristics of skin lesions on color Doppler ultrasound are effective in distinguishing pilomatricoma from epidermoid cyst and dermatofibrosarcoma protuberans.

MATERIALS AND METHODS

Records of patients with pilomatricomas (n = 63), epidermoid cysts (n = 76), and dermatofibrosarcoma protuberans (n = 19) who underwent color Doppler ultrasound evaluation and surgical excision were reviewed. The anatomical distribution and color Doppler ultrasound characteristics of these lesions were analyzed. The 63 pilomatricomas were categorized into five types based on their color Doppler ultrasound characteristics, and the roles of these five types in the differential diagnosis of the aforementioned diseases were studied.

RESULTS

Pilomatricomas, epidermoid cysts, and dermatofibrosarcoma protuberans exhibited some similar characteristics. Dominantly markedly hyperechoic or hyperechoic appearance, posterior acoustic shadowing, and the presence of vascularity were the major characteristics of pilomatricomas. The pilomatricomas could be categorized into five types, with type II having a diagnostic performance of sensitivity of 65.08%, specificity of 98.95%, area under the receiver operating characteristic curve (AUC) of 0.743, positive predictive value of 97.62%, and negative predictive value of 81.03% for the diagnosis of the aforementioned skin diseases.

CONCLUSION

A combination of dominantly markedly hyperechoic or hyperechoic appearance, posterior acoustic shadowing, and the presence of vascularity exhibits higher diagnostic performance for the differential diagnosis of pilomatricomas, epidermoid cysts, and dermatofibrosarcoma protuberans.

Effective resection of dermatofibrosarcoma protuberans using the novel Saturn's rings technique

Dermatofibrosarcoma protuberans (DFSP) is a rare, low-grade sarcoma with locally infiltrative characteristics. A wide excision is made with a 5 cm gross margin. However, recently, Mohs micrographic surgery has emerged as an alternative. In this study, we evaluate a novel method (Saturn's Rings technique) for removing tumors that combines the advantages of wide excision and Mohs micrographic surgery. Between September 2001 and March 2020, 29 patients with DFSP, excluding the head and neck, were treated using Saturn's rings technique. Frozen biopsies were performed at regular intervals under various conditions and depths. If the biopsy was positive, a negative margin was obtained through an additional session. The depth and breadth of excision, reconstruction method, and postoperative recurrence were analyzed. The breadth of excision was evaluated at 1 cm intervals. Only 1 session was required in 12 cases, 2 sessions were needed in 13 cases, and 3 or more sessions were performed in 4 cases. In 24 cases, the depth of excision was limited to above the superficial fascia, with a negative biopsy of the superficial fascia. Local flaps were the most common reconstruction method (n = 21, 72.4%). No cases of recurrence were observed at follow-up (average, 45.7 months). Saturn's rings technique for DFSP maximized the preservation of normal tissue with minimal resection, was advantageous for reconstruction, and yielded good results without recurrence.

Dermatofibrosarcoma protuberans misdiagnosed as sebaceous adenoma and incompletely resected in a child: A case report

BACKGROUND

Dermatofibrosarcoma protuberans is extremely rare in children, making a correct diagnosis by clinicians is usually difficult due to its nonspecific manifestations, the recurrence of dermatofibrosarcoma protuberans after resection has always been a perplexing problem for clinicians. Ultrasound plays an irreplaceable role in the assessment of dermatofibrosarcoma protuberans, although there is a limitation in the diagnosis of the tumor.

CASE REPORT

A 10-year-old boy led by his parents sought for surgical treatment because of the growing mass. Physical examination and preoperative ultrasonography showed that the mass was clear, and the routine resection of mass was performed. Six days postoperatively, histopathological examination indicated that the mass was dermatofibrosarcoma protuberans, and the peripheral and deep resection margins were positive. The patient was informed that a second extended resection was required. The second postoperative pathology showed a negative margin, and the patient was discharged. Postoperative follow-up was assessed by ultrasound examination, and the patient had no abnormalities.

CONCLUSIONS

Dermatofibrosarcoma protuberans should be included in the differential diagnosis when the wide base subcutaneous lesion has suspicious features with high vascularity on ultrasound. If an ultrasound reveals a mass with abundant blood flow, clinicians should routinely perform the extended resection. Wide surgical excision may reduce the risk of reoperation and recurrence, and long-term follow-up is necessary to evaluate postoperative outcomes.

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.