Dermatofibrosarcoma Protuberans. Surg Clin North Am. 2016;96:1031-1046. [PMID: 27542641 DOI: 10.1016/j.suc.2016.05.006]

Racial and Ethnic Differences in Patient Presentation and Treatments in Head and Neck Dermatofibrosarcoma Protuberans

Head and neck dermatofibrosarcoma protuberans (HNDFSP) is a rare neoplasm with a high rate of local infiltration and local recurrence but a low rate of distant metastasis. Given the limited literature on HNDFSP and existing studies pointing to possible racial and ethnic differences, further research is needed to understand important clinical correlates that may impact treatment and prognosis. The National Cancer Database (NCDB) was queried for all cases of HNDFSP diagnosed from 2004 to 2016. Demographic characteristics of the included patients were compared using chi-squared and t-tests. Kaplan-Meier and Cox multivariable regression analyses were performed to assess survival differences. Of the 778 included patients, 526 (67.6%) patients were white, 113 (14.5%) were black, 33 (4.2%) were Asian, 87 (11.2%) were Hispanic, and 19 (2.4%) were classified as Other. White patients presented at a significantly older age (43.8 years) than did black (38.9 years) and Hispanic patients (37.9 years) (p = 0.02). White patients with HNDFSP had significantly higher income status (p = 0.0001), were more likely to be insured (p = 0.0001), and were more likely to have a high school diploma (p = 0.0001). There were no significant racial differences in 5-year (96.1%) or 10-year (92.0%) overall survival. None of the variables yielded a statistically significant value in Cox analysis. Differences exist in HNDFSP presentation between racial groups. Specifically, differences in income, insurance status, education level, and age of presentation exist between these groups. Future studies focused on morbidity are needed to better understand the consequences of these difference on HNDFSP patients.

Rare case of massive inguinal dermatofibrosarcoma protuberans: A case report

DFSP is a cutaneous soft tissue sarcoma. A 35 year old male patient presented with DFSP in the inguinal region which is a rare soft tissue sarcoma which usually presents in the torso, occurring very rarely in the inguinal region. Hence in case of any swelling in the inguinal region, DFSP should be in differential diagnosis.

From oncogenes to tumor suppressors: The dual role of ncRNAs in fibrosarcoma

Fibrosarcoma is a challenging cancer originating from fibrous tissues, marked by aggressive growth and limited treatment options. The discovery of non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and small interfering RNAs (siRNAs), has opened new pathways for understanding and treating this malignancy. These ncRNAs play crucial roles in gene regulation, cellular processes, and the tumor microenvironment. This review aims to explore the impact of ncRNAs on fibrosarcoma's pathogenesis, progression, and resistance to treatment, focusing on their mechanistic roles and therapeutic potential. A comprehensive review of literature from databases like PubMed and Google Scholar was conducted, focusing on the dysregulation of ncRNAs in fibrosarcoma, their contribution to tumor growth, metastasis, drug resistance, and their cellular pathway interactions. NcRNAs significantly influence fibrosarcoma, affecting cell proliferation, apoptosis, invasion, and angiogenesis. Their function as oncogenes or tumor suppressors makes them promising biomarkers and therapeutic targets. Understanding their interaction with the tumor microenvironment is essential for developing more effective treatments for fibrosarcoma. Targeting ncRNAs emerges as a promising strategy for fibrosarcoma therapy, offering hope to overcome the shortcomings of existing treatments. Further investigation is needed to clarify specific ncRNAs' roles in fibrosarcoma and to develop ncRNA-based therapies, highlighting the significance of ncRNAs in improving patient outcomes in this challenging cancer.

Dermatofibrosarcoma Protuberans Arising From a Chronic Wound in the Left Shoulder: A Case Report

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing soft tissue sarcoma, typically presenting as a cutaneous lesion. However, its occurrence in chronic wounds is infrequently documented, posing diagnostic and therapeutic challenges. This report details the case of a 59-year-old female with no significant medical history, presenting with a chronic, non-healing wound on the left shoulder, persisting for three years. Initially a small nodule, it progressed into an ulcerating lesion. Physical examination revealed a contracted scar with restricted shoulder mobility. After obtaining informed consent, a surgical excision of the lesion was performed by an electrocautery. Histopathology confirmed DFSP, characterized by spindle fibrous cells, with skin ulceration and deep dermal infiltration. A split-thickness skin graft achieved successful closure. This case underscores the importance of considering DFSP in chronic, non-healing wounds. Timely intervention and appropriate surgical management are crucial for favorable outcomes.

Dermatofibrosarcoma Protuberans Presenting as a Primary Breast Mass

Dermatofibrosarcoma protuberans (DFSP) is an atypical soft tissue malignancy that affects the dermis and subcutaneous tissue. The cause of DFSP is not clearly understood. This report highlights a rare case of DFSP of the left breast. We report a case of an 18-year-old female with past medical history of type 1 diabetes mellitus, who presented to the breast imaging clinic with a six-month history of left breast lump and associated skin discoloration. The patient had a dedicated left breast ultrasound which showed an indistinct, oval, hyperechoic mass in the superficial breast, measuring 1.4 x 1.0 x 2.5 cm with mild internal vascularity. An ultrasound-guided biopsy of this left breast mass was recommended and performed approximately three weeks later, demonstrating DFSP. The patient was then advised for consultation with Oncology, Surgical Oncology, and Radiation Oncology, to which surgical excision was the final recommendation. The patient had a wide local surgical excision procedure for her left breast mass with surgical pathology confirming negative margins shortly thereafter. This case highlights a great index of suspicion that should be taken when evaluating palpable breast masses with associated skin discoloration in young patients.

Machine learning-based radiomics analysis for predicting local recurrence of primary dermatofibrosarcoma protuberans after surgical treatment

BACKGROUND AND PURPOSE

Dermatofibrosarcoma protuberans (DFSP) is characterized by locally invasive growth patterns and high local recurrence rates. Accurately identifying patients with high local recurrence risk may benefit patients during follow-up and has potential value for making treatment decisions. This study aimed to investigate whether machine learning-based radiomics models could accurately predict the local recurrence of primary DFSP after surgical treatment.

MATERIALS AND METHODS

This retrospective study included a total of 146 patients with DFSP who underwent MRI scans between 2010 and 2016 from two different institutions: institution 1 (n = 104) for the training set and institution 2 (n = 42) for the external test set. Three radiomics random survival forest (RSF) models were developed using MRI images. Additionally, the performance of the Ki67 index was compared with the three RSF models in the external validation set.

RESULTS

The average concordance index (C-index) scores of the RSF models based on fat-saturation T2W (FS-T2W) images, fat-saturation T1W with gadolinium contrast (FS-T1W + C) images, and both FS-T2W and FS-T1W + C images from 10-fold cross-validation in the training set were 0.855 (95% CI: 0.629, 1.00), 0.873 (95% CI: 0.711, 1.00), and 0.875 (95% CI: 0.688, 1.00), respectively. In the external validation set, the C-indexes of the three trained RSF models were higher than that of the Ki67 index (0.838, 0.754, and 0.866 vs. 0.601, respectively).

CONCLUSION

Random survival forest models developed using radiomics features derived from MRI images were proven helpful for accurate prediction of local recurrence of primary DFSP after surgical treatment and showed better predicting performance than the Ki67 index.

Fibrosarcomatous dermatofibrosarcoma protuberans: a rapidly growing 30 cm mass on the posterior scalp

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing sarcoma of the skin and subcutaneous tissue, accounting for around 5 cases per million per year. Fibrosarcomatous transformation of DFSP occurs in 10%-15% of DFSP cases, with a higher risk of local recurrence, metastasis, and death. We present a case of a male in his 30s with a complaint of rapidly progressive mass in the occipital region of the head. Within 1 year, the mass enlarged by >30 cm. Physical examination revealed a skin-colored 40×30 cm mass with an overlying skin necrosis at the posterior scalp. Brain, neck, and chest computed tomography (CT) scans were performed. The mass was surgically excised by wide excision with a 2 cm margin. Pathological report confirmed fibrosarcomatous DFSP Grade 3 with decreased CD34 expression. Delayed reconstruction of free flap and split-thickness skin graft were subsequently performed. No recurrence was detected 3 months postoperatively.

Dermatofibrosarcoma protuberans of the scalp: Surgical management in a multicentric series of 11 cases and systematic review of the literature

BACKGROUND

Dermatofibrosarcoma protuberans is a rare, slow-growing soft-tissue malignancy originating in the dermis that is characterized by an infiltrating growth pattern with a marked tendency of local recurrence. Complete surgical resection with pathological margin clearance must be achieved to reduce the risk of tumor recurrence. Resulting defects often require extensive reconstructive procedures. Dermatofibrosarcoma protuberans of the scalp poses particular challenges owing to the proximity to the face and brain. This study aims to evaluate treatment options and proposes an algorithm for management of scalp dermatofibrosarcoma protuberans based on a multicentric case series and systematic review of the literature.

METHODS

A retrospective multicentric chart analysis of 11 patients with scalp dermatofibrosarcoma protuberans who presented within the last 20 years was performed regarding demographic data, pathological tumor characteristics, and surgical management (resection and reconstruction). Additionally, a further 42 patients (44 cases) were identified through a systematic Preferred Reporting Systems for Systematic Reviews and Meta-Analysis-based review of the literature searching the Medline and Embase databases.

RESULTS

In total, 30 cases were classified as primary and 20 cases as recurring scalp dermatofibrosarcoma protuberans (data from 5 cases were missing). The median tumor size was 24 cm2 (interquartile range 7.8-64), and the median defect size was 55.8 cm2 (interquartile range 48-112). Recurring scalp dermatofibrosarcoma protuberans was more often associated with invasion of deeper layers and required more extensive tumor resection to achieve negative margins. Within the subgroup that was managed with peripheral and deep en face margin assessment, no recurrence was observed. Most patients required local (41. 8%) or free flap (27.8%) reconstruction after dermatofibrosarcoma protuberans resection.

CONCLUSION

Whenever possible, peripheral and deep en face margin assessment-based techniques should be preferred for resection of scalp dermatofibrosarcoma protuberans because they provide superior oncological safety while preserving uninvolved tissue. Patients with locally advanced and recurring scalp dermatofibrosarcoma protuberans often require multidisciplinary treatment including neurosurgery, radiotherapy, and microvascular reconstructive surgery and should be referred to a specialized center.

Oncological efficiency of wide local excision in dermatofibrosarcoma protuberans

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a slow-growing, low- to intermediate-grade malignant sarcoma. Its optimal treatment is resection with wide margins; the likelihood of local control associated with this procedure exceeds 90%. The probability of regional or distant metastases is <5%.

OBJECTIVE

We examined the clinical, epidemiological, and pathological features, the treatment types, and outcomes of patients to investigate the width of safe surgical margins (SM) and how the width of SMs affected recurrence in DFSP.

METHODS

We retrospectively examined the records of 60 patients who were initially operated on with wide local excision for DFSP in the period 2008-2019. Optimal cutoff points for SMs were calculated with the receiver operating characteristic curve analysis and found as 1.925 cm histopathologically and 2.26 cm macroscopically.

RESULTS

During the mean 89.6-month follow-up, local recurrence was seen in 36.7% and distant metastasis in 20% of the patients. Recurrences were significantly related to peripheral resection margins. Analysis by histopathologic cutoff points showed that the local recurrence rate was 84% when SM was ≤1.925 cm, but only 2.85% when >1.925 cm (p = 0.002). Recurrence-free survival was 40.92 months when SM was ≤1.925 cm and 225.75 months when s >1.925 cm (p<0.001). Analysis by macroscopic cutoff points showed that the local recurrence rate was 95.5% when SM was ≤2.26 cm, but only 4% when >2.26 cm (p = 0.001). Recurrence-free survival was 43 months when SM was ≤2.26 cm and 222 months when >2.26 cm (p<0.001). In metastatic patients, progression-free survival was 9 months with cytotoxic chemotherapy, whereas 38.4 months with tyrosine kinase inhibitor (imatinib) (p = 0.002).

CONCLUSION

This study showed SMs >2.5 cm to be sufficiently safe for WLE and optimized the balance among safe margin width, reconstruction need, and surgical morbidity. In metastatic DFSP patients, tyrosine kinase inhibitor imatinib is more effective than cytotoxic chemotherapy for progression-free survival.

Outcome After Surgical Treatment of Dermatofibrosarcoma Protuberans (DFSP): Does it Require Extensive Follow-up and What is an Adequate Resection Margin?

INTRODUCTION

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous tumour of indeterminate malignant potential. The mainstay treatment for DFSP is surgical resection. Given the reported high local recurrence rate, the ideal resection margin for DFSP is unclear. The purpose of this study was to ascertain the local recurrence and metastatic rate of DFSP and DFSP with fibrosarcomatous degeneration (FS-DFSP), with specific attention to margin status in an attempt to address the issue of margin adequacy.

METHODS

Patients treated for DFSP at a single sarcoma centre were identified from a prospective database. DFSP and FS-DFSP patients with and without prior surgery were included. Patients were followed after surgery to monitor complications, local recurrence and metastasis.

RESULTS

The study included 200 patients: 166 patients with DFSP and 34 patients with FS-DFSP. In the DFSP group, nine patients (5.4%) had positive margins, one case (0.6%) developed local recurrence (LR) and no patients developed distant metastases. In the FS-DFSP group, seven patients (20.6%) had positive margins, six patients (17.6%) developed local recurrence (LR) and eight patients (23.5%) developed distant metastases, of which three (37.5%) were in the lungs, one (12.5%) in bone and four (50%) in other soft tissue sites.

DISCUSSION AND CONCLUSION

Local recurrence and metastases are extremely rare in patients with DFSP. Achieving a negative as opposed to a wide surgical margin may be sufficient to avoid local recurrence of most DFSP. We suggest that no ongoing surveillance for local or systemic relapse is required for DFSP patients after negative margin resection. For FS-DFSP, we recommend the same surveillance schedule, based on tumour grade, as other soft tissue sarcoma.

Dermatofibrosarcoma protuberans of the hallux: A case report with review of the literature

INTRODUCTION AND IMPORTANCE

Darier-Ferrand dermatofibrosarcoma (DFS) is a rare mesenchymal tumor with an aggressive local behavior, high local recurrence frequency and low metastatic potential. It commonly presents as a raised slowly growing mass. It usually occurs on trunk and proximal extremities but rarely touches distal extremities such as hands, fingers, or foot below knees.

CASE PRESENTATION

A 15-year-old girl presents with a protuberant painful mass of the right hallux of 2 years. After surgical excision, histological examination revealed a spindle shaped cells with a strong CD34 expression and the diagnosis of Darier-Ferrand dermatofibrosarcoma of the toe was confirmed. We proceeded to a review of the literature of Dermatofibrosarcoma on the toes with the aim to reveal, its clinical presentations, histopathology, and treatment options.

CLINICAL DISCUSSION

DFS represents 0.1 % of all cancers. It is a low-grade sarcoma with a locally aggressive behavior and a low metastatic potential. Only 11 cases of DFS of the toes have been reported in the literature. It usually occurs in the trunk, and proximal extremities. Histological and immunohistochemical examination are mandatory to confirm the diagnosis with diffuse expression of CD34 by the tumoral cells. Surgery is the standard treatment for localized and resectable lesions.

CONCLUSION

Darier-Ferrand Dermatofibrosarcoma is an uncommon and recurrent dreadful tumor, that rarely occurs on toes, but should be considered in front of persistent slowly growing foot lesions.

Diagnosis and differential diagnosis of dermatofibrosarcoma protuberans: Utility of high-resolution dynamic contrast-enhanced (DCE) MRI

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a kind of low-grade malignant spindle cell neoplasm, the diagnosis, and treatment, which have markedly attracted clinicians' attention for its repeated recurrence. High-resolution magnetic resonance imaging (HR-MRI) has shown unique capabilities in diagnosis of various cutaneous tumors.

MATERIALS AND METHODS

Data of 29 patients with clinically suspected DFSPs and undergoing dynamic contrast-enhanced (DCE) HR-MRI preoperatively were prospectively collected. The HR-MRI qualitative features were evaluated and compared. The DCE-associated quantitative parameters and the time-signal intensity curve (TIC) types were provided using DCE sequences.

RESULTS

A total of 7 DFSPs, nine dermatofibromas (DF, including four cases of cellular variant [CDF]), 12 keloids, and one nodular fasciitis were enrolled. DFSP showed the largest major diameter and the deepest depth. Five DFSPs (71.4%) showed ill-defined margins as well as infiltration of peripheral adipose. All DFSPs showed irregular shape. Most DFSPs presented hyperintensity on T₂ WI (71.4%) and iso-intensity on T₁ WI (85.7%). Six cases (85.7%) had significant enhancement, and six cases (85.7%) had homogeneous enhancement. There were significant differences of K^trans , K_ep , V_e and iAUC values among DFSPs, DFs, and keloids, and DFSP had the highest values for these parameters. Six DFSPs (85.7%) and four CDFs (100%) showed type-III TICs, while the other lesions showed type-Ⅰor type-Ⅱ TICs.

CONCLUSIONS

DCE-HR-MRI could show the growth characteristics of DFSPs, which was of great value for the diagnosis and differential diagnosis of DFSPs and was helpful for the determination of treatment options, thereby to improve the prognosis of patients.

Preoperative 3D Reconstruction Model in Slow Mohs Surgery for Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is a type of skin cancer that is extremely rare. Its standard treatment is either surgical wide-local excision (WLE) or Mohs micrographic surgery (MMS). Which method has the lowest recurrence rate is unknown. Dermatofibrosarcoma protuberans is an uncommon soft tissue sarcoma with a high propensity for recurrence. It has always remained a clinical challenge. More technology is needed to treat the disease. We reviewed our cases and published experience and evaluated whether 3D modeling could precisely define tumor morphological characteristics and assist excision in slow Mohs surgery. There were 18 dermatofibrosarcoma protuberan cases enrolled. They were treated in Shanghai Ninth People's Hospital from 2014 to 2019. All the 18 included patients presented with primary disease and no metastasis. All subjects had undergone thorough imaging examinations including CT and MRI. The 3D tumor reconstruction models were created for their tumors. We precisely estimated tumor boundaries and sizes according to those 3D models. Afterward, patients underwent slow Mohs surgery and surgical repair of tissue defects following tumor resection. The 3D tumor reconstruction models were successfully established. The predicted tumor volumes were measured in all 18 cases. The average volume was 38.5 cm3 (range: 8.4 cm3-183.6 cm3), which allowed for accurately locating the tumor. Tumors were completely removed in one stage of slow MMS surgery. In the second-stage surgery, the defects were repaired by different surgical methods including direct soft tissue closure, skin grafting, local flaps, or free flaps. Most patients experienced no significant complications. This practice indicated that the combination of a 3D reconstruction model and slow Mohs surgery achieves more precise and complete DFSP resection to decrease the recurrence rate.

Dermatofibrosarcoma Protuberans in Active Duty Military Personnel: A Case Report

Dermatofibrosarcoma protuberans (DFSP) is an uncommon, soft tissue sarcoma with a high rate of local recurrence, low rate of distant metastasis, and infiltrative growth. We report two cases of DFSP in young active duty military personnel. Both cases underwent primary excision at the Armed Forces Capital Hospital with positive surgical margins and underwent re-excision at Samsung Medical Center. Dermatofibrosarcoma protuberans is a rare finding, and wide local excision with or without skin flap remains the procedure of choice. Awareness of DFSP in young patients is important for proper diagnosis and treatment and to achieve local control. Complete excision of the tumor with a clear surgical margin and thorough surveillance after surgery are recommended for service members to maintain their active duty status and to prevent ineffective combat conditions.

Risk factors related to postoperative recurrence of dermatofibrosarcoma protuberans: A retrospective study and literature review

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade malignant soft tissue tumor characterized by rosette-like infiltrative growth. Postoperative recurrence of this tumor is very common.

AIM

To evaluate the risk factors related to recurrence after wide local excision (WLE) of DFSP and to guide clinical diagnosis and treatment.

METHODS

The medical records of 44 DFSP patients confirmed by pathology at our hospital from 2012 to 2019 were retrospectively reviewed. The relationship between clinical features, tumor characteristics, treatment, and recurrence risk were analyzed, and the possible risk factors for postoperative tumor recurrence were evaluated.

RESULTS

There were 44 patients in total, including 21 males and 23 females. The median progression free survival was 36 mo (range, 1-240 mo). Twenty patients were treated for the first time, while 24 had previous treatment experience. Forty-two cases were followed for 25.76 ± 22.0 mo, among whom four (9.52%) experienced recurrence after WLE (rate was 9.52%). The recurrence rate in the recurrent group was higher than that in the patients with primary tumor (19.05% vs 0%, P = 0.028). Eighteen cases had a history of misdiagnosis (rate was 40.91%). The recurrence rate among patients with previous experience of misdiagnosis was significantly higher than in patients without (68% vs 36.84%, P = 0.04). The tumor diameter in patients with a history of treatment was larger than in patients treated for the first time (4.75 ± 0.70 cm vs 2.25 ± 0.36 cm, P = 0.004).

CONCLUSION

To sum up, the clinical manifestations of DFSP are not specific and are easily misdiagnosed, thus commonly causing the recurrence of DFSP. After incomplete resection, the tumor may rapidly grow. Previous recurrence history may be a risk factor for postoperative recurrence, and tumor location may have an indirect effect on postoperative recurrence; however, we found no significant correlation between sex, age, course of the disease, or tumor size and postoperative recurrence.

Association between surgical excision margins and outcomes in patients with dermatofibrosarcoma protuberans: A meta-analysis

Dermatofibrosarcoma protuberans (DFSP) is a tumor with low-grade malignancy and high recurrence rates. Wide local excision (WLE) is essential for DFSP, but its surgical excision margin is controversial. This study aimed to examine whether resection margin is associated with the prognosis of patients with DFSP by systematically reviewing related literature. Studies that evaluated the relationship between excision margins and outcomes after WLE were retrieved from the Cochrane Library, PubMed, Embase, and Web of Science databases. Relative risk (RR) estimates and 95% confidence intervals (CIs) were measured via a random-effect model to evaluate the subsequent outcomes: recurrence rate, mortality, and positive surgical margin rate. Sensitivity and subgroup analyses were simultaneously carried out. The meta-analysis of eight observational literatures demonstrated a significant positive correlation of ≥3 cm margin with the recurrence rate (RR = 0.17, 95% CI 0.09-0.31) and the positive surgical margin rate (RR = 0.09, 95% CI 0.02-0.46). The same result was observed in the recurrence rate in all subgroups. The stability of the above outcomes was authenticated via sensitivity analyses. Our meta-analysis illustrated that excision with <3 cm surgical margin exhibited an increased risk of poor DFSP prognosis (high recurrence rate and increasing positive margin rate).

Cutaneous Sarcomas

Cutaneous sarcomas represent a rare group of tumors presenting in the head and neck. In this article, we discuss specific sarcoma tumor types and their presentation, pathogenesis, histologic findings, and management recommendations. Tumors to be reviewed include dermatofibrosarcoma protuberans, atypical fibroxanthoma, pleomorphic dermal sarcoma, cutaneous leiomyosarcoma, and angiosarcoma.

Clinicopathological features of fibrosarcomatous dermatofibrosarcoma protuberans and the construction of a back-propagation neural network recognition model

BACKGROUND

Fibrosarcomatous dermatofibrosarcoma protuberans (FS-DFSP) is a form of tumor progression of dermatofibrosarcoma protuberans (DFSP) with an increased risk of metastasis and recurrence. Few studies have compared the clinicopathological features of FS-DFSP and conventional DFSP (C-DFSP).

OBJECTIVES

To better understand the epidemiological and clinicopathological characteristics of FS-DFSP.

METHODS

We conducted a cohort study of 221 patients diagnosed with DFSP and built a recognition model with a back-propagation (BP) neural network for FS-DFSP.

RESULTS

Twenty-six patients with FS-DFSP and 195 patients with C-DFSP were included. There were no differences between FS-DFSP and C-DFSP regarding age at presentation, age at diagnosis, sex, size at diagnosis, size at presentation, and tumor growth. The negative ratio of CD34 in FS-DFSP (11.5%) was significantly lower than that in C-DFSP (5.1%) (P = 0.005). The average Ki-67 index of FS-DFSP (18.1%) cases was significantly higher than that of C-DFSP (8.1%) cases (P < 0.001). The classification accuracy of the BP neural network model training samples was 100%. The correct rates of classification and misdiagnosis were 84.1% and 15.9%.

CONCLUSIONS

The clinical manifestations of FS-DFSP and C-DFSP are similar but have large differences in immunohistochemistry. The classification accuracy and feasibility of the BP neural network model are high in FS-DFSP.

Multidisciplinary surgical treatment approach for dermatofibrosarcoma protuberans: an update

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous sarcoma that has remained a challenge for oncologic and reconstructive surgeons due to a high rate of local recurrence. The objective of this study is to investigate the oncologic and reconstructive benefits of employing a multidisciplinary two-step approach to the treatment of DFSP. A retrospective review was conducted using a prospectively collected database of all patients who underwent resection and reconstruction of large DFSPs by a multidisciplinary team, including a Mohs micrographic surgeon, surgical oncologist, dermatopathologist, and plastic and reconstructive surgeon, at one academic institution from 1998-2018. Each patient underwent Mohs micrographic surgery for peripheral margin clearance (Step 1) followed by wide local excision (WLE) of the deep margin by surgical oncology and immediate reconstruction by plastic surgery (Step 2). 57 patients met inclusion criteria. Average defect size after WLE (Step 2): 87.3 cm² (range 8.5-1073.5 cm²). Mean follow-up time was 37 months (range 0-138 months). There were no cases of recurrence. A two-step multidisciplinary surgical treatment approach for DFSP minimizes risk of recurrence, decreases patient discomfort, and allows immediate reconstruction after deep margin clearance.

The efficacy of Mohs micrographic surgery over the traditional wide local excision surgery in the cure of dermatofibrosarcoma protuberans

Usually most patients with dermatofibrosarcoma protuberans (DFSP) may present rather late when the tumor is in protuberant phase due to its rarity and indolent onset. It has a high propensity for local recurrence and destructive nature. Management of DFSP requires a biopsychosocial and Multidisplinary approach regardless of the clinical or immunohistochemical variant. Surgery is the Gold standard management of localized disease. DFSP rarely exhibits any lymphatic or hematogenous dissemination. It is because of its high recurrence rate associated with Wide Local Excision (WLE), the introduction of Mohs micrographic surgery (MMS) has really helped in reducing the rates of recurrence of DFSP. Thus, the aim of this meta-analysis and systemic review is to advocate for MMS over WLE for DFSP and other cutaneous malignancies using DFSP as a prototype. The objective of this study were to conduct a meta-analysis on comparative surgical methods used in the cure of DFSP with regards to WLE verses MMS, to evaluate the cure rates with relation to recurrence rates, offer a recommendation on the various treatment modalities based on the location of lesion, and use of adjuvant therapy in different clinical-medical setups. A comprehensive retrospective analysis search in EMBASE, Google Scholar and Medline (PubMed) for studies published from 2008 to 2018 containing the surgical management of DFSP with WLE verses MMS were reviewed. Five studies of moderate-quality evidence (level B) with a pooled patient load of 684 was analyzed and found for recurrence of DFSP after WLE and MMS to be 9.10% and 2.72% respectively after an average follow-up time for both groups of 5.32 years with a female predominance of 1.58. The trunk is the commonest site for the DFSP lesion which was at 52.80% then the upper and lower extremities zones and the head and neck zones at 31.75% and 15.45% respectively. The pooled adjusted odds ratio (OR) analysis indicated that there was a direct relationship with regards the reduced recurrence rate of DFSP in the MMS group compared to the WLE group (OR:0.31;95%; CI :0.17-0.56). Furthermore, there was significant association between the reduced recurrence rate with the MMS in DFSP patients with a statistical P-value of 0.0001 at 95% CI. The expected increased recurrence rate by zones was in WLE head and neck zone at 38.19% then trunk and extremities zone at 13.34%. In the MMS group it was at of 23.4% as compared to 16.0% in the head and neck zone. Mohs Micrographic Surgery (MMS) is more efficacious in the cure rate and recurrence reduction of DFSP and should be advocated for as first line therapy especially in high recurrence prone zones.

Fibrosarcomatous dermatofibrosarcoma protuberans from scar following trauma

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft tissue neoplasm of low metastatic potential notable for its progressive growth and high rate of local recurrence after surgical excision. Fibrosarcomatous transformation of DFSP (FS-DFSP) is a rare variant characterized by higher rates of local recurrence and metastasis. Trauma has been hypothesized as a potential risk factor for the development of DFSP, although clear evidence has been lacking. In this study, we report a case of FS-DFSP that was found arising from a previously stable scar following a traumatic injury. A 49-year-old male was diagnosed with keloid scars following a motor vehicle accident where he sustained trauma. 12 years later, a large tumor developed immediately after a second traumatic event to the primary scar. Pathology of the excisional biopsy specimen demonstrated FS-DFSP with focal areas consistent with keloid and hypertrophic scar. This observation demonstrates the development of DFSP from underlying scar following a clear history of trauma. Furthermore, it suggests trauma as a possible trigger for the fibrosarcomatous transformation of DFSP.

Bednar Tumour Occurring after Malignant Melanoma Excision

We report the case of a seventy-four-year-old man with a slow-growing 2 cm mass on the back that arose near the surgical scar of previously excised melanoma, invasive to a Breslow depth of 3 mm. Preoperative clinical diagnosis was "in-transit" melanoma metastasis. After surgical excision, histopathologic examination revealed a dermal nodular proliferation of spindle cells arranged in storiform pattern, with mild pleomorphism, infiltrating around appendages and into the subcutaneous tissue. Immunohistochemical investigation documented diffuse positivity for CD34 and vimentin of spindle cells. Scattered dendritic cells, containing dark pigment in varying proportion and positive for S100, Melan-A and HMB-45, were also observed. A final diagnosis of Bednar tumour was formulated. Subsequently, the patient developed numerous metastases from the primary melanoma and died after 18 months. Bednar tumour is a rare pigmented variant of dermatofibrosarcoma protuberans of intermediate malignant potential. The presence of pigmented cells in Bednar tumour requires careful differential diagnosis with malignant or benign pigmented skin tumours. The clinical history of a Bednar tumour developing close to the scar of a previous melanoma gives the opportunity of a critical and intriguing discussion about the potential origin of pigmented cells in this rare variant of dermatofibrosarcoma protuberans.

Image-Guided Thermal Ablative Therapies in the Treatment of Sarcoma

OPINION STATEMENT

Percutaneous thermal ablation, including microwave ablation (MWA), radiofrequency ablation (RFA), and cryoablation, is a well-established focal treatment option for primary and metastatic malignancies. While published literature specific to ablation of sarcomas is relatively lacking compared with non-sarcomatous malignancies, what is available is promising. In situations where a focal treatment option is desired, strong consideration should be given to percutaneous thermal ablation, in addition to surgery and radiation therapy. A significant advantage of percutaneous thermal ablation over surgery and radiation includes the repeatability of ablation, as there is no absolute limit on the number of times an ablation can be performed. Compared with surgery, ablation offers the potential of decreased recovery time, a less invasive procedure, and is often performed in patients deemed not medically fit for surgery.

Dermatofibrosarcoma Protuberans

OPINION STATEMENT

Dermatofibrosarcoma protuberans (DFSP) is a slow growing tumor with a very low metastatic potential but with significant subclinical extension and great capacity for local destruction. Thus, the first surgeon approached with such challenging tumor must attempt to cure the patient with a method that spares healthy tissue and ensures an optimal oncological, functional, and esthetic result. The treatment of DFSP often requires a multidisciplinary approach. Depending on location, dermatologic surgeons, surgical oncologists, head and neck surgeons, neurosurgeons, plastic surgeons, and occasionally medical oncologists may be involved with the management. Mohs micrographic surgery (MMS) is the preferred method when available. In our institution, most of the DFSP cases are often advanced cases; thus, dermatologic surgeons obtain clear margins peripherally and other surgical specialties assist with resection of the fascia and any critical deeper structures. When MMS is not available, wide local excision (at least 2- to 3-cm margins of resection) with exhaustive pathologic assessment of margin status is recommended, and it is best to confirm tumor extirpation prior to any reconstruction. Subclinical extension of the tumor could be related to the size; how long it has been growing or histological markers that are unknown right now. No clinical trials comparing MMS vs WLE are available, and further research should be focused on these subjects as well as the use of imatinib and other targeted therapies for recurrent and metastatic tumors and for neoadjuvant treatment.