A comparison of frozen and paraffin sections in dermatofibrosarcoma protuberans

Comparing Mohs micrographic surgery and wide local excision in the management of head and neck dermatofibrosarcoma protuberans: a scoping review

Dermatofibrosarcoma protuberans (DFSP) is a rare, locally aggressive cutaneous sarcoma with a propensity for recurrence. Its management, particularly in the head and neck (H&N) region, presents unique challenges. This study aimed to evaluate the effectiveness of Mohs micrographic surgery (MMS) compared to wide local excision (WLE) in treating H&N DFSP and its impact on recurrence rates and tissue preservation. A comprehensive search was conducted in PubMed/MEDLINE, yielding 29 relevant studies. We included studies comparing MMS and WLE in adult patients with H&N DFSP and reporting local recurrence outcomes. Data were analyzed using random effects analysis, with a meta-analysis performed for comparative studies. Analysis of studies demonstrated a lower recurrence for MMS. Comparative analysis of five studies involving 117 patients showed a significantly lower recurrence rate in the MMS group (2%) compared to the WLE group (19%). Margin status varied between studies, with some achieving negative margins at shorter distances. In the management of H&N DFSP, MMS has emerged as a superior surgical technique, consistently associated with reduced recurrence rates and the potential for tissue preservation. The adoption of MMS should be considered for its capacity to achieve negative margins with fewer processing steps, particularly in anatomically complex regions like the H&N.

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.

Mohs micrographic surgery in dermatofibrosarcoma protuberans: Rate and risk factors for recurrence in a prospective cohort study from the Spanish Registry of Mohs Surgery (REGESMOHS) and review of the literature

Characterization of patients, surgery procedures and the risk factors for dermatofibrosarcoma protuberans (DFSP) recurrences is poorly defined. In this study, we aimed to describe the demographics, tumor characteristics and interventions of DFSP treated with Mohs micrographic surgery (MSS) to determine the rate and risk factors for recurrence. Data were collected from REGESMOHS, a nationwide prospective cohort study of patients treated with MMS in Spain. From July 2013 to February 2020, 163 patients with DFSP who underwent MMS were included. DFSP was mostly located on trunk and extremities. Recurrent tumors had deeper tumor invasion and required higher number of MMS stages. Paraffin MMS was the most frequently used technique. Overall recurrence rate was 0.97 cases/100 person-years (95% IC = 0.36-2.57). No differences were found in epidemiological, tumor, surgery characteristics or surgical technique (frozen or paraffin MMS [p = 0.6641]) in terms of recurrence. Median follow-up time was 28.6 months with 414 patient-years of follow-up. In conclusion, we found an overall low recurrence rate of DFSP treated with MMS. None of the studied risk factors, including MMS techniques, was associated with higher risk for recurrence.

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.

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.

A Comparison of Mohs Micrographic Surgery and Wide Local Excision for Treatment of Dermatofibrosarcoma Protuberans With Long-Term Follow-up: The Mayo Clinic Experience

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a soft tissue tumor with slow infiltrative growth and local recurrence if inadequately excised.

OBJECTIVE

To compare long-term outcomes after Mohs micrographic surgery (MMS) and wide local excision (WLE).

MATERIALS AND METHODS

Records of patients with DFSP surgically treated with WLE or MMS from January 1955 through March 2012 were retrospectively reviewed.

RESULTS

Mean follow-up for patients treated with MMS (n = 67) and WLE (n = 91) was 4.8 and 5.7 years, respectively. Twenty-eight patients (30.8%) with WLE had recurrence (mean, 4.4 years), whereas only 2 (3.0%) with MMS had recurrence (1.0 and 2.6 years). Recurrence-free survival rates at 1, 5, 10, and 15 years were significantly higher with MMS (p < .001). Mean preoperative lesion sizes were similar (5-6 cm) between the 2 groups, whereas mean (standard deviation) postoperative defect sizes were 10.7 (4.3) cm and 8.8 (5.5) cm for WLE and MMS, respectively (p = .004). Primary closure was used for 73% of MMS cases, whereas WLE more commonly used flaps, grafts, or other closures (52%). Two Mohs layers typically were required for margin control.

CONCLUSION

Surgical excision with meticulous histologic evaluation of all surgical margins is needed for DFSP treatment to achieve long-term high cure rates and low morbidity.

Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is a rare superficial soft tissue sarcoma. Its rarity precludes large prospective studies. Clinical diagnosis requires an high index of suspicion. Effective management requires an appreciation of tumor biology and the nature of the characteristic infiltrative growth pattern. DFSP tends to recur locally, with a low risk of dissemination. Aggressive surgical resection with widely negative margins is essential to management. Radiotherapy may be indicated in special circumstances. Understanding the molecular pathogenesis has resulted in use of tyrosine kinase inhibitor therapy for patients with locally advanced disease or in metastatic disease. DFSP patients require long-term follow-up.

The efficacy of adjuvant radiotherapy in dermatofibrosarcoma protuberans: a systemic review and meta-analysis

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare and locally aggressive tumour, with a high recurrence rate, even after complete surgical excision. Adjuvant radiotherapy (RT) has been suggested to reduce the risk of local recurrence after inadequate surgical resection in patients with narrow or positive surgical margins. However, the overall efficacy of adjuvant RT has not been well studied because of the rarity of DFSP and lack of an appropriate comparison group.

OBJECTIVE

We sought to evaluate the efficacy of adjuvant RT for DFSP by conducting a systemic review and meta-analysis to provide a more evidence-based measure of its effectiveness.

METHODS

We conducted a systemic review of articles published before 31 June 2015. Due to the rarity of the disease, we included all studies that reported DFSP patients who received adjuvant RT (postoperatively). The pooled recurrence rates were analysed from these extracted data.

RESULTS

Twelve studies met the inclusion criteria. The pooled estimate of the recurrence rate for all adjuvant radiotherapy was 11.74% (95% CI 7.4-17.38; n = 167). Patients with positive/close had a pooled recurrence rate of 14.23% (95% CI 8.13-22.49; n = 92), whereas there was no recurrence in patients with negative margins. The pooled estimate of the recurrence rate between surgery alone and surgery combined with adjuvant radiotherapy showed no significant difference (odds ratio 0.31, P = 0.07), although there was a trend that adjuvant RT had a lower recurrence rate than surgery alone.

CONCLUSION

Adjuvant RT might be considered for all patients undergoing surgical excision, even if a negative surgical margin has been achieved. Furthermore, for patients with large or recurrent tumours, especially when wide excision with negative margin would result in a significant functional or cosmetic deficit, postoperative radiotherapy is highly recommended in order to achieve a lower recurrence rate.

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.

Dermatofibrosarcoma protuberans (DFSP): predictors of recurrence and the use of systemic therapy

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft tissue malignancy that typically presents with local invasion but rarely metastasizes. We examine clinicopathologic factors associated with disease-free survival (DFS) in patients with primary and recurrent DFSP and evaluate responses to multimodality therapy.

MATERIALS AND METHODS

Patients treated for DFSP were identified in a prospectively maintained database. Clinicopathologic factors associated with DFS were analyzed using univariate and multivariate analysis.

RESULTS

A total of 244 patients with DFSP were identified. Median follow-up was 50 months. A total of 14 patients had local recurrence (LR), and 2 patients had distant recurrence (DR), with a median time to recurrence of 35 months. At time of last follow-up, 70% and 47% of patients showed no evidence of disease (NED) in the primary (n = 197) and recurrent groups (n = 47), respectively. On univariate analysis, tumor location and depth were associated with DFS in the primary group, while margin status (R1 vs. R0) was associated with DFS in the LR group. On multivariate analysis, only depth (primary group) and margin status (LR group), remained significant. Also, 22 patients had therapy other than surgical resection: 14 radiotherapy, 4 tyrosine kinase inhibitor (TKI) only, 2 conventional chemotherapy only, and 2 chemotherapy plus TKI. Responses to other therapies were variable.

CONCLUSIONS

DFS after treatment for DFSP is strongly predicted by tumor depth in the primary setting and margin status in recurrent tumors. The treatment for DFSP in the primary or recurrent setting is excision with negative margins, resulting in low recurrence rates and infrequent metastatic spread. Multimodality treatment, especially TKI use, can be effective, but is not curative.

Dermatofibrosarcoma protuberans: 35 patients treated with Mohs micrographic surgery using paraffin sections

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) has conventionally been treated with wide local excision. More recently Mohs micrographic surgery (MMS) has been advocated.

OBJECTIVES

To assess our departmental experience with DFSP in the context of a literature review relating to DFSP treated with MMS.

METHODS

This was a case review of 35 patients with DFSP treated between 1998 and 2009 with MMS using paraffin-embedded sections.

RESULTS

Seventeen patients required one horizontal layer to clear their tumour, 10 patients needed two and eight patients needed three layers or more. The median preoperative clinical size was 6 cm(2) (range 0·75-54·8) and the median postoperative wound size was 46·8 cm(2) (range 4-145·2). Tumour persistence has not been observed in any of our patients after a median follow-up duration of 29·5 months (range 6-146).

CONCLUSIONS

We present 35 DFSP patients, none of whom showed persistent tumour after treatment with 'slow' MMS using paraffin sections. We advocate MMS as the treatment of choice for DFSP, especially for tumours over the head and neck region where tissue conservation is particularly important.

A Primer of Mohs Micrographic Surgery: Uncommon Indications

Mohs micrographic surgery has been used for the treatment of tumors other than basal and squamous cell carcinomas. Parameters to be considered when deciding on a treatment include location, size, growth pattern, and recurrence rates. It is important to consider that sometimes the high-risk nature of the tumor is more significant than the need for tissue sparing. Modifications to the Mohs micrographic surgery technique may be used to ensure diagnostic accuracy and confirm complete removal of the lesion (e.g., immunohistochemical staining and paraffin-embedded sections).

Sarcomas cutâneos primários

Os sarcomas com apresentação cutânea primária são tumores raros e de grande heterogeneidade histológica. Com a evolução da oncologia cutânea e da cirurgia dermatológica, os dermatologistas têm sido cada vez mais requisitados para o diagnóstico e orientação terapêutica de tumores menos freqüentes. Este artigo de revisão analisa os sarcomas cutâneos primários observando suas características clínicas, etiopatogênicas e histológicas, bem como aspectos do tratamento e evolução. Enfatiza os sarcomas de maior relevância para o dermatologista, como angiossarcoma, dermatofibrossarcoma protuberans, fibroxantoma atípico, leiomiossarcoma, lipossarcoma, tumor maligno de bainha de nervo periférico e sarcoma epitelióide. O sarcoma de Kaposi não é abordado devido a suas características individuais específicas.

Frozen section of skin specimens

CONTEXT

Skin cancers are the most common malignancies in this country. Treatment of these tumors often involves assessment of margins, which may be performed by frozen section.

OBJECTIVE

This article discusses indications for frozen section, various approaches to gross examination of specimens, Mohs micrographic surgery, diagnostic pitfalls, methods to improve diagnostic accuracy, and special techniques.

DATA SOURCES

The authors' extensive experience and review of the published literature.

CONCLUSIONS

Frozen sections play a vital role in the evaluation of margins of basal cell carcinomas and squamous cell carcinomas. The role of frozen sections in evaluation of soft tissue tumors is controversial. With rare exception, they have no role in the evaluation of melanocytic tumors.

Dermatofibrosarcome de Darier Ferrand : traitement par chirurgie micrographique de Mohs avec inclusion en paraffine

INTRODUCTION

Dermatofibrosarcoma protuberans is a tumor of intermediate malignancy characterized by its aggressive local growth due to pseudopodium-like outgrowths and marked propensity to recur after surgical excision. To achieve complete cure with conventional surgery, surgical margins up to 5 cm are required, leading to wide scars. Mohs' micrographic surgery is used for the removal of certain malignant tumors, both ensuring complete excision by examination of all margins as well as minimizing normal tissue loss. However, differentiating minimal residual tumor from normal skin can be difficult on the frozen sections used in Mohs' micrographic surgery. Our aim was to develop a procedure of Mohs' micrographic surgery in conjunction with rush formalin-fixed, paraffin-embedded tangential sections.

PATIENTS AND METHODS

Ten consecutive cases have been prospectively treated since 1998. Under local anesthesia, the tumor was first excised including lateral margin of 1 cm and a deep margin including the underlying muscle aponevrosis. A 2 to 3 mm thick horizontal section of the surgical bed was then removed, rush formalin-fixed, paraffin-embedded, tangentially sectioned, hematin-eosin stained, and eventually stained with an anti-CD34 monoclonal antibody. While waiting for pathology results, the surgical bed was not definitively closed. If excision was incomplete, an oriented complementary excision was performed.

RESULTS

Excision was complete after the first stage in 7 patients and incomplete only deeply in 3. Lateral surgical margins were reduced to 1.3 cm in all patients, facilitating wound closure: direct suture (5 patients), controlled wound healing (3 patients) or flap coverage (2 patients). No recurrence has been observed after a mean follow-up of 26 months.

DISCUSSION

The use of Mohs' micrographic surgery in conjunction with rush formalin-fixed, paraffin-embedded tangential sections reduce surgical margins in dermatofibrosarcoma protuberans. This procedure would be interesting in difficult sites, such as the genitalia, the breast, or the periarticular regions. Other cases, and longer follow-up are however necessary to validate this promising technique.

Historique, principes, analyse critique de l’efficacité et indications de la chirurgie micrographique de Mohs

OBJECTIVES

To systematically review the literature for studies reporting on the role of Mohs' micrographic (MMS) surgery in the treatment of skin tumors. To show how it is performed in France.

DESIGN

We reviewed with a quality grid all studies indexed in MEDLINE before 2003/01/01 and published in English or French. Data were extracted by two independent reviewers.

MAIN OUTCOME MEASURES

Quality of clinical studies, recurrence rates, number of patients lost to follow-up.

RESULTS

No randomized study was found among the 493 references found. Studies of lower quality, on procedures similar to MMS, or previous systematic reviews were therefore selected. In tumors such as basal (BCC) or spinous (SCC) cell carcinoma, microcystic adnexal carcinoma, dermatofibrosarcoma protuberans, and Merkel cell carcinoma, MMS commonly induced lower recurrence rates than figures reported for conventional treatments and/or reduced surgical margins. Studies on melanoma were of low quality.

CONCLUSIONS

Although no evidence-based guidelines could be developed, MMS should be used mainly for larger, morphea, micronodular or infiltrative-type, or recurrent BCCs located in danger zones, but also (sometimes with a slightly modified procedure) in microcystic adnexal carcinomas, dermatofibrosarcoma protuberans, Merkel cell carcinoma, and in aggressive forms of SCC. Randomized, controlled studies should be performed.