Wide local excision vs. Mohs Tübingen technique in the treatment of dermatofibrosarcoma protuberans: a two-centre retrospective study and literature review

Current patterns of care and outcomes for dermatofibrosarcoma protuberans: An international multi-institutional collaborative

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous sarcoma with an infiltrative growth pattern that makes it challenging to clear margins. High quality data regarding DFSP natural history, management, and outcomes are limited.

METHODS

Data were retrospectively collected for adult DFSP patients who underwent resection at 10 institutions in eight countries. Demographics, tumor characteristics, treatment strategies, and outcomes were analyzed.

RESULTS

Analysis included 347 patients consisting of young (median, 42 years), White (76.2%), males (54.2%) with truncal lesions (57.3%). The majority (76.8%) were symptomatic at presentation. Preoperative imaging was used in 55.9% of cases. Diagnosis was established with excisional biopsy in 50.9% versus incisional biopsy in 25.0% of cases. Despite planned margins of >1.0 cm in 67.4% of cases, only 69.0% of patients achieved R0 resection. Twenty-two percent of patients underwent at least one re-excision. R0 resection was achieved at a second procedure in 80.2% and a third procedure in 86.2%. Ultimately, R0 resection was feasible in 89.5% of all patients. Fibrosarcomatous transformation (FST) was observed in 12.6%. In total, 6.6% (N = 23) recurred (17 local, six distant). Of the six distant recurrences, 50.0% had FST. With a median follow-up of 47.0 months, disease-specific survival rate was 98.8%. In multivariable analysis, R0 margins at index resection were associated with wider circumferential margins and non-FST histology.

CONCLUSIONS

In this international, multicenter collaborative, DFSP practice patterns were heterogeneous but achieved favorable recurrence rates and survival. Multiple excisions to clear margins remain commonplace and can inform future efforts to optimize margin selection.

Review on the Role of Paraffin-embedded Margin-controlled Mohs Micrographic Surgery to Treat Skin Tumors

Paraffin-embedded margin-controlled Mohs micrographic surgery (PMMS) includes various procedures such as slow Mohs or deferred Mohs technique, the Muffin and Tübingen techniques, and staged margin excision, or the spaghetti technique. PMMS is a variation of conventional Mohs micrographic surgery (MMS) that allows histopathological examination with delayed margin control. PMMS requires minimum training and may be adopted by any hospital. The setback is that PMMS can require procedures across multiple days. PMMS lowers the rate of recurrence of basal cell carcinoma vs wide local excision in high-risk basal cell carcinoma, and improves the rates of recurrence and survival in lentigo maligna. PMMS can be very useful in high-risk squamous cell carcinoma treatment. Finally, it is a promising technique to treat infrequent skin neoplasms, such as dermatofibrosarcoma protuberans, or extramammary Paget's disease, among others. In this article, we present a literature narrative review on PMMS, describing techniques and indications, and highlighting long-term outcomes.

Review on the Role of Paraffin-embedded Margin-controlled Mohs Micrographic Surgery to Treat Skin Tumors

Paraffin-embedded margin-controlled Mohs micrographic surgery (PMMS) includes various procedures such as slow Mohs or deferred Mohs technique, the Muffin and Tübingen techniques, and staged margin excision, or the spaghetti technique. PMMS is a variation of conventional Mohs micrographic surgery (MMS) that allows histopathological examination with delayed margin control. PMMS requires minimum training and may be adopted by any hospital. The setback is that PMMS can require procedures across multiple days. PMMS lowers the rate of recurrence of basal cell carcinoma vs wide local excision in high-risk basal cell carcinoma, and improves the rates of recurrence and survival in lentigo maligna. PMMS can be very useful in high-risk squamous cell carcinoma treatment. Finally, it is a promising technique to treat infrequent skin neoplasms, such as dermatofibrosarcoma protuberans, or extramammary Paget's disease, among others. In this article, we present a literature narrative review on PMMS, describing techniques and indications, and highlighting long-term outcomes.

Novel role of fluorescent in situ hybridization technique (FISH) in recommended surgical margins of dermatofibrosarcoma protuberans: A preliminary study

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare skin tumor. There is no standard recommendation for its surgical management. The currently used histological analysis are HES (hematoxylin eosin saffron) staining and immunohistochemistry for CD34 expression in particular cases. Fluorescent in situ hybridization (FISH) technique is only used to qualify the DFSP as translocated or non-translocated and is not used as a diagnostic method. The aim of our study was to determine by FISH (as a diagnostic method) whether cancerous cells that could not be identified through HES staining±immunohistochemistry were present at the two-centimeter margins that were found to be tumor-free.

METHODS

Samples from patients who underwent surgery between 2010 and 2018 were collected. Intralesional and peripheral (at 2cm margins) paraffin slides were included. An average of 7.4 slides per specimen was analyzed. Firstly, the preselected slides were reread by a senior pathologist to confirm the absence of microscopic findings of DFSP at 2cm margins. Secondly a FISH analysis was used as a quantitative diagnostic approach, in order to find the t(17;22) translocation.

RESULTS

Among the seven specimens that included 2cm margins, two samples presented one or more translocations, which were not visible in standard morphology assessments at two centimeters tumor-free margins.

CONCLUSIONS

FISH analysis can have a new role in defining tumor-free margins. This would reduce the incidence of disease recurrence after resection and improve the post-operative complementary care.

Dermatofibrosarcoma Protuberans: A Study of 148 Patients

INTRODUCTION

Dermatofibrosarcoma protuberans (DFSP) is the most common sarcoma of the skin. Although distant metastases are infrequent, DFSP is highly aggressive locally with frequent local recurrences. It has been reported that the presence within the tumour of areas histopathologically mimicking fibrosarcoma may increase the risk of recurrence.

OBJECTIVE

The objective of this study was to review the clinical features of our patients with DFSP and the factors associated with recurrence of the tumour, focussing on the presence of fibrosarcomatous areas.

METHODS

Retrospective study of patients with DFSP diagnosed in 1990-2021 in a tertiary university hospital. The medical records were reviewed to obtain the following data: age, sex, tumour location, diameter, evolution time, presence of fibrosarcomatous areas, development of recurrence, and follow-up. Factors possibly associated with disease-free survival were analysed with Kaplan-Meier method and multivariate Cox regression.

RESULTS

148 patients (74 women/74 men, mean age 46.28 years, SD 14.431) were included in the study. Tumours involved the head and neck in 15 cases, thorax in 31, abdomen in 16, upper back in 43, lower back in 10, upper extremities in 10, and lower extremities in 23. Fibrosarcoma-like areas were observed in 16 tumours (10.81%). In 17 patients (11.49%), recurrences were observed (13 local recurrences, 3 lung metastasis, and 1 local recurrence with lung metastasis). Fibrosarcomatous DFSP recurred more frequently than classic DFSP (50% vs. 6.82%, respectively), and its disease-free survival was significantly lower (p < 0.001). In multivariate Cox regression, the presence of fibrosarcomatous areas was the only factor influencing disease-free survival.

CONCLUSIONS

It is important to identify the fibrosarcomatous variant since it recurs more frequently and has lower recurrence-free survival. Distant metastases, mainly in the lung, are also more frequent in fibrosarcomatous DFSP.

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.

Wide local excision, Mohs micrographic surgery, and reconstructive options for treatment of dermatofibrosarcoma protuberans of the breast: A retrospective case series from Mayo Clinic

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) of the breast is a dermal fibroblastic neoplasm requiring wide excisional margins due to recurrence rates ranging from 26 to 60%. The current literature on reconstructive options and utility of Mohs micrographic surgery for DFSP of the breast is scarce. We describe surgical management of DFSP of the breast at our institution with the largest case series reported to date.

METHODS

A retrospective review was performed of women who underwent surgery for DFSP of the breast at our institution between 1990 and 2019. Continuous data was summarized using mean, median, and range; categorical data was summarized with frequency count and percentage. Preoperative lesion size and postoperative defect size were evaluated using 2-sided Fisher exact test, and p-values < 0.05 were considered statistically significant.

RESULTS

Nine patients underwent wide local excision (WLE) with reconstruction including pedicled latissimus dorsi flaps (n = 2), local flap advancement (n = 2), mastectomy with implant (n = 1), oncoplastic breast reduction (n = 1), and skin grafts (n = 3). Nine underwent Mohs micrographic surgery (MMS) with complex primary closure. Mean postoperative maximum wound defect size for WLE was 10.8 cm versus 7.0 cm for MMS with no statistical significance (p = 0.77). Mean preoperative maximum lesion size for WLE was 6.4 cm versus 3.3 cm for MMS with no statistical significance (p = 0.07). Complications with WLE included wound dehiscence in three patients and seroma in one patient. No complications were reported with MMS and primary closure. Recurrence was reported in one WLE patient, which was successfully detected despite flap coverage and resected without complications. Median follow-up for the patients without recurrence was 5.0 years, with two patients in MMS cohort lost to follow-up. Five-year overall survival was 100%.

CONCLUSIONS

MMS and WLE are both viable surgical options for managing DFSP of the breast. MMS could potentially minimize reconstructive needs due to smaller average defect size and result in fewer complications but may also result in asymmetry. Immediate flap reconstruction, especially in larger defects, can achieve excellent aesthetic outcomes for patients with DFSP of the breast without compromising detection of disease recurrence.

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.

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.

Evidence from Clinical Studies Related to Dermatologic Surgeries for Skin Cancer

Simple Summary

Although significant progress in pharmacotherapy for skin cancer has been made in the past several years, surgical removal of primary skin cancer is still the first choice of treatment unless distant metastases are evident. In the surgical treatment of primary skin tumors, the surgical margin is critical not only for reducing the possibility of tumor recurrence but also for minimizing the cosmetic and functional complications associated with wide local excision. In contrast, dermatologic surgeries including lymph node dissection and skin graft can cause various complications, and these complications are frequently associated with significant morbidity and discomfort. In this review, we summarize the evidence from previous clinical studies regarding the optimal surgical margin for skin cancer and the methods for diminishing the complications associated with dermatologic surgery.

Abstract

Despite the significant progress made in the past several years in pharmacotherapies for skin cancer, such as BRAF/MEK inhibitors, immune checkpoint inhibitors, and Hedgehog pathway inhibitors, surgical removal of primary skin cancer is still the first choice of treatment unless distant metastases are evident. In cases of lymph node metastases with clinically palpable lymphadenopathy, lymph node dissection (LND) is typically performed for most skin cancers. In the surgical treatment of primary skin tumors, the surgical margin is critical not only for reducing the possibility of tumor recurrence but also for minimizing the cosmetic and functional complications associated with wide local excision. In contrast, dermatologic surgery can cause various complications. Although skin graft is frequently used for reconstruction of the surgical defect, extensive graft necrosis may develop if optimal stabilization of the graft is not obtained. LND also sometimes causes complications such as intraoperative or postoperative bleeding and postoperative lymphoceles. Moreover, as in other types of surgery, surgical site infection, intraoperative anxiety, and intraoperative and postoperative pain may also develop. These complications are frequently associated with significant morbidity and discomfort. In this review, we summarize the evidence from previous clinical studies regarding the optimal surgical margin for skin cancer and the methods for diminishing the complications associated with dermatologic surgery.

Dermatofibrosarcoma Protuberans Recurrence After Wide Local Excision Versus Mohs Micrographic Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

Local recurrence (LR) rates of dermatofibrosarcoma protuberans (DFSP) treated with different surgical modalities are unknown.

OBJECTIVE

To evaluate the differences in LR rates of DFSP treated with wide local excision (WLE) versus Mohs micrographic surgery (MMS).

MATERIALS AND METHODS

Pertinent studies of DFSP treated with either WLE or MMS were identified through a search of multiple databases, including Ovid MEDLINE (1946-2018), Embase (1988-2018), Web of Science (1975-2018), and Scopus (1970-2018). Comparative 2-arm and noncomparative single-arm studies were assessed through meta-analyses.

RESULTS

Of the 517 studies identified, 88 met inclusion criteria (12 comparative studies; 76 single-arm studies). In the 12 comparative studies, 352 patients with DFSP underwent MMS and 777 patients with DFSP underwent WLE. The LR rate was 1.7% after MMS and 3.7% after WLE (odds ratio, 1.549; 95% CI, 0.710-3.381; p = .27). In the 76 noncomparative studies, 980 patients underwent MMS (LR rate, 1.5%; 95% CI, 0.9%-2.1%; p < .001), and 2,215 patients underwent WLE (LR rate, 9.4%; 95% CI, 7.5%-11.3%; p < .001).

CONCLUSION

The LR rate of DFSP in patients treated with MMS is lower than in patients treated with WLE. Because of high rates of postoperative DFSP LR, MMS should be strongly considered when available.

Determination of Margins for Tumor Clearance in Dermatofibrosarcoma Protuberans: A Single-Center Study of 222 Cases Treated With Modified Mohs Surgery

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is an invasive skin tumor traditionally associated with very high recurrence rates when treated with conventional surgery (CS).

OBJECTIVE

To calculate the minimum margin that would have been required to achieve complete tumor clearance with hypothetical CS. To analyze DFSP characteristics and Mohs micrographic surgery (MMS) effectiveness in treatment of this tumor.

MATERIALS AND METHODS

Minimum margin was calculated by measuring the largest distance from the visible edge of the tumor to the edge of the surgical defect. Tumor variables (age, sex, size, time since onset, and location) were correlated with surgical variables (number of stages and minimum margin).

RESULTS

We studied 222 cases of DFSP treated with MMS. A mean of 1.47 MMS stages and a mean minimum margin of 1.23 cm were required to achieve tumor clearance. Tumors on the head and neck required significantly more stages and a significantly wider margin. Tumor size was positively correlated with time to diagnosis, age, and number of MMS stages.

CONCLUSION

Tumors located on the head and neck have greater subclinical extension. Tumor size was also a predictor of surgical difficulty, but time to diagnosis was not.

A review of Mohs Micrographic Surgery for skin cancer: Part 1 - melanoma and rare skin cancers

Mohs micrographic surgery is a precise and effective method commonly used to treat high risk basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) on the head and neck. Whilst the majority of evidence for Mohs relates to keratinocyte cancers, there is published evidence for other types of skin cancer. This review aims to discuss the evidence for using MMS to treat six different types of skin cancer, including melanoma, lentigo maligna, dermatofibrosarcoma protuberans, atypical fibroxanthoma, microcystic adnexal carcinoma and pleomorphic dermal sarcoma, particularly in the context of survival rates and cancer recurrence. These cancers were chosen as there was sufficient literature for inclusion and given MMS is most useful when cancers are contiguous, rather than for cancers with marked metastatic potential such as angiosarcoma or merkel cell carcinoma. We searched Medline, Pubmed and Embase using the keywords: 'melanoma', 'mohs micrographic surgery', 'lentigo maligna', 'dermatofibrosarcoma protuberans', 'atypical fibroxanthoma', 'microcystic adnexal carcinoma' and 'pleomorphic dermal sarcoma' along with their appropriate synonyms, to identify the relevant English-language articles from the year 2000 onwards given that literature for Mohs on non-keratinocyte is sparse prior to this date. A MeaSurement Tool to Assess systematic Reviews (AMSTAR) was used to assess the validity of systematic reviews. Further high-quality, multi-centre randomised trials are necessary to establish the indications and efficacy of MMS for rarer cancers, particularly for AFX and PDS, where limited studies were identified.

Molecular targeted therapy for advanced or metastatic soft tissue sarcoma

Soft tissue sarcomas are a form of rare and heterogeneous neoplasms with high recurrence rate and mortality. Over the past decades, less progress has been achieved. Surgical management with or without adjuvant/neoadjuvant radiotherapy is still the first-line treatment for localized soft tissue sarcomas, and chemotherapy is the additional option for those with high-risk. However, not all patients with advanced or metastatic soft tissue sarcomas benefit from conventional chemotherapy, targeted therapy takes the most relevant role in the management of those resistant to or failed to conventional chemotherapy. Heterogeneous soft tissue sarcomas vary from biological behavior, genetic mutations, and clinical presentation with a low incidence, indicating the future direction of histotype-based even molecule-based personalized therapy. Furthermore, increasing preclinical studies were carried out to investigate the pathogenesis and potential therapeutic targets of soft tissue sarcomas and increasing new drugs have been developed in recent years, which had started opening new doors for clinical treatment for patients with advanced/metastatic soft tissue sarcomas. Here we sought to summarize the concise characteristics and advance in the targeted therapy for the most common subtypes of soft tissue sarcomas.

Cutaneous soft tissue sarcomas: survival-related factors

Cutaneous sarcomas are a heterogeneous group of rare mesenchymal neoplasms representing less than 1% of malignant tumors. Histology report remains the cornerstone for the diagnosis of these tumors. The most important clinicopathologic parameters related to prognosis include larger tumor size, high mitotic index, head and neck location, p53 mutations, depth of infiltration and histological grade, vascular and perineural invasion as well as the surgical margins status. Applying advanced biopsy techniques might offer more precise assessment of surgical margins, which constitutes a significant precondition for the management of these tumors. The management of cutaneous soft tissue sarcomas requires a multidisciplinary approach. Surgery remains the standard treatment, nonetheless adjuvant therapy may be required, consisting of radiotherapy, chemotherapy, and molecular targeted therapies to improve treatment outcomes. The role of molecular profiling in the treatment of uncontrolled disease is promising, but it may be offered to a relatively small proportion of patients and its use is still considered experimental in this setting. Due to the rarity of the disease, there is a need for knowledge and experience to be shared, pooled, organized and rationalized so that recent developments in medical science can have a major impact on the disease course. Multicenter clinical trials are needed to improve the care of patients with cutaneous sarcomas.

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.

Raman spectroscopy based diagnosis of dermatofibrosarcoma protuberans: Case report

Dermatofibrosarcoma protuberans is a rare disease and this pathology provokes insufficient oncological alertness among clinicians. A possible way to increase the accuracy of early diagnosis of rare skin neoplasms is "optical biopsy" using Raman spectroscopy tissue response. This case report of a 32-year-old woman with a dermatofibrosarcoma protuberans demonstrates that Raman spectroscopy based "optical biopsy" can help to diagnose rare tumors.

Local Recurrence Rates of Skin Tumors After Resection With Complete Circumferential Peripheral and Deep Margin Assessment-Identification of High-Risk Entities

BACKGROUND

The local recurrence rates of malignant skin tumors after micrographic controlled surgery using complete circumferential peripheral and deep margin assessment (CCPDMA) are reported to be low. However, in daily practice, tumor entities with a significantly higher recurrence rate are found.

OBJECTIVE

The aim of the investigation was to identify these high-risk tumors to develop approaches for risk stratification.

PATIENTS AND METHODS

We included different malignant tumors that were surgically treated and examined with CCPDMA using paraffin sections and H&E staining. Re-excisions were performed until the tumor was completely removed.

RESULTS

Ninety-nine thousand three hundred seventy-two tumors were included in the study; the follow-up period was 4 years (median). Eight tumor entities were identified as high-risk entities, showing a significantly higher local recurrence rate of over 20%: desmoplastic squamous cell carcinoma, desmoplastic melanoma, Merkel cell carcinoma, microcystic adnexal carcinoma, pleomorphic sarcoma, liposarcoma as well as angiosarcoma, and extramammary Paget's disease.

CONCLUSION

Complete circumferential peripheral and deep margin assessment allows complete control of the resection margins and enables skin-sparing resections with low recurrence rates for basal cell carcinomas, nondesmoplastic squamous cell carcinomas, lentiginous melanomas, and dermatofibrosarcoma protuberans. However, other tumors show significantly higher recurrence rates and therefore need to be classified as high-risk tumors.

Dermatofibrosarcoma Protuberans: A Clinicopathologic and Therapeutic Analysis of 254 Cases at a Single Institution

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade tumor that typically does not metastasize but often recurs. Fibrosarcomatous DFSP (FS-DFSP) is associated with a substantially higher rate of metastasis and a poorer prognosis.

OBJECTIVE

This study sought to investigate the epidemiological, histopathological, and clinical characteristics of DFSP, especially with a particular focus on FS-DFSP.

MATERIALS AND METHODS

Clinical data from 254 patients treated between January 1999 and July 2018 were retrospectively reviewed. Endpoints of the study were the incidence of significant disease-related clinical events.

RESULTS

Follow-up data from 211 patients were available for analysis, with a median follow-up time of 38 months (range: 1-196 months). The 5-year recurrence-free survival rate of patients underwent wide-local excision (WLE) was 97.1%. Patients underwent WLE exhibited a significantly decreased recurrence rate relative to patients treated through local excision (2.9% vs 37.7%; p < .001). Fibrosarcomatous DFSP had significantly higher rates of distant metastasis (66.7% [n = 4] vs 2.0% [n = 4]; p < .001) and long-term mortality (50.0% [n = 3] vs 1.5% [n = 3]; p < .001), compared with classical DFSP (C-DFSP).

CONCLUSION

Wide-local excision is an effective means of reducing DFSP recurrence. Rates of metastasis are higher for FS-DFSP than for C-DFSP, with the former having significantly poorer outcomes.

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).

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.

Resection and Reconstructive Options in the Management of Dermatofibrosarcoma Protuberans of the Head and Neck

Objective To discuss resection and various reconstructive options in patients with dermatofibrosarcoma protuberans (DFSP). Methods This study was conducted at Shifa International Hospital, Islamabad, Pakistan, from May 2018 to December 2019. All patients aged 20 years or above of either gender who were diagnosed to have DFSP over this period were included in the study. All the patients underwent wide local excision of the tumor under general anesthesia. A peroperative frozen section was conducted in all the cases to confirm complete excision. Immediate reconstruction was performed following the tumor excision. The choice of reconstruction, i.e. free, regional, or local flap was based on the size of the resultant defect. Results The mean age of the patients was 37.11 ±10.91 years. There were 12 (66.7%) males and six (33.3%) females. The mean duration of the disease was 11.22 ±2.94 months. The affected anatomical site showed that the face was involved in the majority, nine (50%) patients, followed by the scalp in four (22.2%), nape of the neck in three (16.7%), and supraclavicular region in two (11.1%) patients. In most of the cases, the free flap was observed, i.e. (n=9, 50%), followed by a regional flap in seven (38.9%), and the local flap in two (10.1%) patients. Conclusion Wide local excision of the disease, confirmed on frozen section, offers improved survival. Among DFSP of the head and neck, the face was found to be the affected anatomical site in half the cases. Also, reconstruction following tumor excision with a free flap is the most favorable option among patients with DFSP.

Adequate surgical margins for dermatofibrosarcoma protuberans - A multi-centre analysis

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive tumour. Adequate margins have a positive impact on recurrence rates. The aim of this study is to assess how adequate margins are achieved and secondly which additional treatment modalities might be necessary to achieve adequate margins.

MATERIAL & METHODS

Patients with DFSP treated between 1991 and 2016 at three tertiary centres were included. Patient- and tumour characteristics were obtained from a prospectively held database and patient files.

RESULTS

A total of 279 patients with a median age of 39 (Interquartile range [IQ], 31-50) years and a median follow-up of 50 (IQ, 18-96) months were included. When DFSP was preoperatively confirmed by biopsy and resected with an oncological operation in a tertiary centre, in 86% was had clear pathological margins after one excision. Wider resection margins were significantly correlated with more reconstructions (p = 0.002). A substantial discrepancy between the primary surgical macroscopic and the pathological margins was found with a median difference of 22 (range, 10-46) mm (Fig. 1). There was no significant influence of the width of the pathological clear margins (if > 1 mm) and the recurrence rate (p = 0.710).

CONCLUSION

The wider the resection margins, the more likely it is to obtain clear pathological margins, but the more likely patients will need any form of reconstruction after resection. The aim of the primary excision should be wide surgical resection, where the width of the margin should be balanced against the need for reconstructions and surgical morbidity.

Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is an uncommon dermal neoplasm that exhibits a high rate of local recurrence and infiltrative behavior, but has a low risk of metastasis. It arises as a slowly progressive, painless pink or violet plaque. Histologically, DFSP is characterized by a monomorphous spindle cell proliferation in a storiform pattern. The gold standard of treatment is surgical resection with negative margins. In cases where obtaining clear margins is not possible, radiation and systemic therapy with tyrosine kinase inhibitors, such as imatinib mesylate, has been shown to be effective.

Patterns of infiltration and local recurrences of various types of cutaneous sarcomas following three-dimensional histology

BACKGROUND

Cutaneous sarcomas are rare and characterized by pathogenetic heterogeneity. Knowledge about local infiltration patterns and recurrence rates may be useful in improving patient care and outcomes. The objective of the present study was to compare these two characteristics in sarcomas that had been treated using the identical surgical procedure.

PATIENTS AND METHODS

Between 2006-2010, 84 patients with various types of sarcoma underwent surgery followed by three-dimensional histology. Tumor entities included dermatofibrosarcoma protuberans (DFSP, 54 patients), leiomyosarcoma (ten patients), rhabdomyosarcoma (one patient), angiosarcoma (seven patients) as well as atypical fibroxanthoma (AFX, three patients) and cutaneous undifferentiated pleomorphic sarcoma (UPS, nine patients). Median follow-up was four years (range: 2-6 years).

RESULTS

Local recurrence rates among patients with primary DFSP were 2.2 %. All patients undergoing re-excision were subsequently tumor free. Patients with leiomyosarcoma, rhabdomyosarcoma, AFX, and cutaneous UPS experienced no local recurrence; however, one individual developed in-transit metastasis (UPS) (8.3 %). Three patients with angiosarcoma developed local recurrence (43 %), two of whom remained tumor free following re-excision. Two angiosarcoma patients died from distant metastases (29 %). Both DFSP and especially angiosarcoma lesions exhibited extensive subclinical growth.

CONCLUSIONS

Recurrence rates of cutaneous sarcomas following three-dimensional histology are low. Local recurrences are readily manageable by re-excision. Angiosarcoma is characterized by extensive superficial growth, aggressive biological behavior, and predominantly hematogenous spread.

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.

Dermatofibrosarcoma protuberans: surgical management of a challenging mesenchymal tumor

INTRODUCTION

Dermatofibrosarcoma protuberans (DFSP) is a rare, low-grade malignant mesenchymal tumor of the soft tissue, characterized by slow infiltrative growth and common local recurrence, with rare distant metastases.

PATIENTS AND METHODS

We present a retrospective study of nineteen patients who were diagnosed with DFSP and operated at our institution in > 10-year period. We examined the clinicopathological parameters with special emphasis on the margin status regarding the clinical outcome and the follow-up.

RESULTS

A total of eight cases underwent re-excision at our institution following primary excision or incisional biopsy performed at a different institution. Seven cases received excision after incisional biopsy at our institution. Four patients developed recurrent disease following primary excision with histological R0 margins at other institutions and received re-excision at our institution. All excisions at our institution resulted in R0 margins with no recurrence recorded at last follow-up (6 to 175; mean 84 months). The mean margin for those who received resection at our institution was 1.67 cm. Negative margins upon primary excision were achieved using a mean margin width of 2.04 cm. Most common tumor localization was the trunk (10 cases).

CONCLUSION

Awareness of this rare entity is important for a prompt diagnosis and a proper management of the disease. The greatest clinical challenge in the management of DFSP is achieving local control. Complete excision of the tumor with surgical margin widths of at least 2 cm is recommended.

Current Update on the Molecular Biology of Cutaneous Sarcoma: Dermatofibrosarcoma Protuberans

OPINION STATEMENT

Cutaneous sarcoma is a group of malignant mesenchymal tumors primarily involving the dermis, and it is characterized by extreme clinicopathological heterogeneity. Although its occurrence rate is rare, dermatofibrosarcoma protuberans (DFSP) is one of the most common types of dermal sarcoma. DFSP grows slowly and tends to relapse locally after inadequate resection. There are various histological variants of DFSP tumors and it often mimics benign lesions such as dermatofibroma and scar, which make accurate diagnosis difficult and delayed, and some cases progress to the stage where the tumor is unresectable. Recent advancements in cancer genetics and molecular biology methods have elucidated the COL1A1-PDGFB fusion gene, some novel fusion gene variants and pathways related to DFSP pathogenesis that have resulted in the evolution of cutaneous sarcoma diagnosis and treatment. For example, some clinical studies have confirmed the efficacy of imatinib methylate, an αPDGFR-targeted therapy for unresectable or metastatic DFSP. The present review summarizes recent updates in DFSP research, diagnostics, and treatment.

Patient indications for Mohs micrographic surgery: a clinical practice guideline

Objective

The purpose of the present work was to develop evidence-based indications for Mohs micrographic surgery in patients with a diagnosis of skin cancer.

Methods

The guideline was developed by Cancer Care Ontario's Program in Evidence-Based Care, together with the Melanoma Disease Site Group and the Surgical Oncology Program, through a systematic review of relevant literature, patient- and caregiver-specific consultation, and internal and external reviews.

Recommendation 1

Given a lack of high-quality, comparative evidence, surgery (with postoperative or intraoperative margin assessment) or radiation (for those who are ineligible for surgery) should remain the standard of care for patients with skin cancer.

Recommendation 2

Mohs micrographic surgery is recommended for patients with histologically confirmed recurrent basal cell carcinoma of the face and is appropriate for primary basal cell carcinomas of the face that are larger than 1 cm, have aggressive histology, or are located on the H zone of the face.

Recommendation 3

Mohs micrographic surgery should be performed by physicians who have completed a degree in medicine or equivalent, including a Royal College of Physicians and Surgeons of Canada Specialist Certificate or equivalent, and have received advanced training in Mohs micrographic surgery.

A case of aggressive giant dermatofibrosarcoma protuberance occurring in the parotid gland

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The parotid region is a very rare site with few published case reports, shares the common features of trunk DFSP.

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Radiotherapy or chemoradiotherapy can be applied to large and recurrent cases, but with unclear benefit.

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Dermatofibrosarcoma protuberans is a rare tumor, with infiltrative margins, high local recurrence rate, and rare distant metastasis.

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CD34 immunohistochemistry is a reliable marker for difficult diagnostic cases.

Introduction

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous malignancy that arises from the dermis and invades deeper tissue. The cellular origin of DFSP is not clear. Evidence supports the cellular origin being fibroblastic, histiocytic, or neuroectodermal.

Presentation of case

A 38 years old, women presented with slow-growing large right parotid mass. A total parotidectomy performed with auriculectomy and reconstruction using ALT flap. Diagnosis confirmed by pathology and immunohistochemistry. Tumor recurred in 10 months, the second surgery with subsequent chemoradiotherapy performed. Patient initially treated with wide resection, 4 cycles of chemotherapy and postoperative radiotherapy 40 Gy, with the recurrence in 10 months. We performed a second surgery followed by radiotherapy. She is disease-free for more than two years under follow-up.

Discussion

The main treatment of DFSP is surgical resection with wide negative margins or Moh’s surgery. Advanced cases treated with addition of radiotherapy or chemoradiotherapy, but with unclear benefits. In our case, huge tumor located in the parotid region recurred after initial surgery and adjuvant treatment.

Conclusion

Clinically, DFSP usually manifest as well circumscribed, slow-growing, smooth, and painless masses. In cases with advanced tumor in parotid region, recurrence may occur despite aggressive initial treatment with wide resection and chemoradiotherapy.

Dermatofibrosarcoma protuberans – the impact of radiation therapy: a single institution series

Background

Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive intermediate malignancy.

Objective

The purpose of this retrospective analysis is to determine the efficacy of radiation therapy (RT) in local control of DFSP.

Patients and methods

The recurrence-free survival (RFS) for 45 patients treated for DFSP at our institution was estimated and compared between surgery alone and postoperative RT groups.

Results

Age range of the patients were in the third and fourth decades; males:females=2:1; most common site: anterior abdominal wall; tumours >5 cm in size in 75%; low grade in 77·8%; margins positive in 31·8% and <5 mm margins in 45·5%. Two-thirds of patients had at least one recurrence before presentation to our institution. RT dose was >50 Gy in 88% of patients. The patients treated with postoperative RT had poorer prognostic factors compared with surgery alone: they were males (17 versus 13 patients), and presented with high-grade tumours (5 versus 1 patients), multiple recurrences prior to presentation (25 versus 20 patients) and positive or <5 mm margins (22 versus 12 patients). Median follow-up for surgery alone group was 17 (1–152) months and for postoperative RT group, this was 54 (5–121) months. RFS at 5 years was 77·1% for surgery alone and 87·9% for postoperative RT group but was not statistically significant. The median time to recurrence was 4 years.

Conclusion

RT delays the time to recurrence in DFSP. RT improves the outcome of DFSP for recurrent tumours and with positive margins.

Dermatofibrosarcoma protuberans (DFSP) arising from a keloid scar - A case report

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous sarcoma with an indolent early course that may be misdiagnosed for benign skin pathology. In this case-report we highlight an instance of DFSP arising from a keloid scar de novo and present a reconstruction with a local pedicled LD flap. We subsequently appraise the related literature and discuss the diagnostic challenges.

Patient Indications for Mohs Micrographic Surgery: A Systematic Review

The purpose of the present review was to describe evidence-based indications for Mohs micrographic surgery (MMS) in patients with a diagnosis of skin cancer. Relevant studies were identified from a systematic MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews search of studies published from 1970 to 2017. Randomized controlled trials (RCTs), prospective and retrospective comparative studies with greater than 30 patients, and single-arm retrospective studies with multivariate analyses were included. A total of 2 RCTs, 3 prospective studies, and 16 retrospective studies (14 comparative and 2 single-arm) were included. Data on recurrence rate, cure rate, complications, cosmesis, and quality of life were extracted. Surgery (with postoperative or intraoperative marginal assessment) or radiation for those who are ineligible for surgery should remain the standard of care for patients with skin cancer given the lack of high-quality, comparative evidence. MMS is recommended for those with histologically confirmed recurrent basal cell carcinoma (BCC) of the face and is appropriate for primary BCCs of the face that are >1 cm, have aggressive histology, or are located on the H zone of the face. The available evidence is difficult to generalize to all patients with skin cancer because the evidence did not adequately cover non-BCC skin cancers; however, those skin cancers can be considered on a case-by-case basis for MMS. MMS should be performed by physicians who have completed a degree in medicine or equivalent, including a Royal College of Physicians and Surgeons of Canada Specialist Certificate or equivalent, and have received advanced training in MMS.

Guidelines for Diagnosis and Treatment of Cutaneous Sarcomas: Dermatofibrosarcoma Protuberans

Sarcomas comprise a broad group of tumors, many of whose biological behavior and aggressiveness differ from one type to another. The therapeutic approach is generally multidisciplinary and often complex. Developments in surgical and oncological dermatology during the last few decades have positioned dermatologists as specialists in the diagnosis and treatment of skin cancer. The aim of this article is to review the main soft tissue sarcomas that typically affect the skin. Dermatofibrosarcoma protuberans is a low-grade malignant sarcoma. It exhibits slow-growth, is locally invasive, and has low metastatic potential (<3%). Mohs micrographic surgery is the treatment of choice. The COL1A1-PDGFB translocation should be analyzed in cases of unclear diagnosis and when it is necessary to identify candidates for tyrosine kinase inhibitors. Imatinib is indicated for the treatment of locally advanced and metastatic dermatofibrosarcoma protuberans.

Dermatofibrosarcoma Protuberans: Retrospective Single Center Analysis Over 16 Years

Dermatofibrosarcoma protuberans (DFSP) is rare mesenchymal neoplasia with a high risk of local recurrence but a low risk of metastatic spread. Tumor cells express CD34 and show a characteristic translocation t(17;22)(q22;q13). We analysed the documented cases at the Department of Dermatology and Allergology between 08/2001 and 08/2017. The diagnosis had been confirmed by histology and immunohistology in all cases. We identified four adults and a pediatric patient with DFSP. All patients were treated by wide surgical excision and controlled by three-dimensional histologic margin control. We observed no recurrence and no metastatic spread. We discuss prognostic factors and emerging treatments.