Reducing surgical margins in dermatofibrosarcoma protuberans using the pathological analysis technique 'vertical modified technique': a 5-year experience

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.

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.

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).

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.

"Deep" vertical Mohs and closure with a tumor-free flap for dermatofibrosarcoma protuberans: A case report

Dermatofibrosarcoma protuberans is an uncommon low-grade malignant tumor that can invade locally and rarely metastasize. Dermatofibrosarcoma protuberans has a high rate of local recurrence due to incomplete excision, especially in deep tissues. Morbidity is often related to multiple local recurrences and removal of excessive tissue with large, complex repairs. We present a case of incompletely excised dermatofibrosarcoma protuberans after initial wide local excision. We subsequently employed a "deep" vertical Mohs micrographic surgical technique to remove the remaining tumor while creating a flap with the tumor-free superficial portion to preserve tissue and avoid a complicated repair. The patient is tumor-free for 7 years.

Mohs micrographic surgery for dermatofibrosarcoma protuberans (DFSP): a single-centre series of 76 patients treated by frozen-section Mohs micrographic surgery with a review of the literature

Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade sarcoma that typically presents with local invasion but rarely metastasises. Surgical excision remains the first-line treatment for DFSP. There are no randomised controlled or prospective studies comparing wide local excision (WLE) with Mohs micrographic surgery (MMS), but available evidence from the retrospective studies and case series available has consistently shown higher recurrence rates for standard surgery and WLE than for MMS. Combined recurrence rates of data within the last 20 years for WLE have been reported at 7.3% compared with 1.1% for MMS. Our aim was to review the clinical details and recurrence rates of DFSP cases treated with frozen-section MMS in our centre between 1996 and February 2013. The relevant data were collected from the case notes. It involved 76 patients with nine of these patients lost to follow-up. In the remaining 67 (67/76) cases, the recurrence rate was 1.5% during the mean follow-up period of 50 months (2-132). This is comparable to recurrence rates for the MMS in the literature [20,21]. Our series is the largest series for frozen-section MMS reported to date. Based on these findings and the current literature evidence, we advocate MMS as the treatment of choice for DFSP in all locations.