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

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.

High-frequency ultrasound-assisted Mohs micrographic surgery for the treatment of dermatofibrosarcoma protuberans

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a superficial sarcoma characterized by infiltrative growth with tentacle-like borders. Mohs micrographic surgery (MMS) is the preferred treatment option for DFSP. However, the imprecise boundary localization in MMS leads to an increased number of Mohs layers required and a longer surgery time. High-frequency ultrasound has excellent tissue recognition capability for DFSP, allowing for precise boundary marking.

MATERIALS AND METHODS

In this study, we retrospectively analyzed 14 cases of DFSP treated with MMS using preoperative ultrasound localization and three-dimensional reconstruction at Xiangya Hospital over the past 5 years. We also reviewed previous studies on MMS for DFSP treatment.

RESULTS

It was found that the average number of Mohs layers for patients after preoperative ultrasound localization was 1.57, ranging from 1 to 3, which was less than the previously reported 1.86 layers, ranging from 1 to 12. This effectively reduced the number of Mohs layers required.

CONCLUSIONS

By utilizing preoperative high-frequency ultrasound to determine the boundaries and depth of DFSP, the number of Mohs layers can be effectively reduced, leading to less workload for pathological examination, shorter operation time, and reduced surgical risks for patients. Ultrasound imaging data can be used for three-dimensional reconstruction, enabling less experienced Mohs surgeons to have a visual understanding of the morphology and extent of infiltration of the lesions. This aids in developing optimal surgical plans, smoothing the learning curve, and promoting the wider adoption of MMS.

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.

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.

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.

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.

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.

Mohs micrographic surgery for cutaneous malignancies: A focus review of its indications in pediatric age groups

Mohs micrographic surgery (MMS) is a highly specialized technique that has been successful in the treatment of a variety of skin tumors. The technique can be performed as an outpatient procedure and encompasses surgical excision and intraoperative assessment of tumor margins in one setting by the same physician. The process ensures precise margin control with maximal preservation of healthy tissues. Mohs micrographic surgery has been practiced worldwide, including in the United States, Europe (United Kingdom, Germany, Spain, Netherlands, Switzerland), and Australia. Although it is commonly performed in adults with greater success, it has been discussed less frequently in children. In this article, we describe several cutaneous tumors in children and the role of Mohs micrographic surgery in their management. A PubMed search was conducted to review the most common cutaneous tumors in children treated using Mohs micrographic surgery. In this review, we discuss indications for Mohs micrographic surgery and pertinent studies examining success rates in children. Mohs micrographic surgery has been used to treat several tumors in children and offers the advantage of high cure rates and tissue conservation. This report emphasizes the benefits of Mohs micrographic surgery in children and highlights several cutaneous tumors for which it has been used to treat successfully.

Diagnosis and Management of Dermatofibrosarcoma Protuberans in a 3-Year-Old Patient

In this case report, we present a 3-year-old boy with a diagnosis of dermatofibrosarcoma protuberans (DFSP) on the dorsum of his right hand. Although rarely metastatic, DFSP is highly locally invasive and can cause considerable local morbidity. In the hand, DFSP is uncommon in the young pediatric patient. In our patient, the tumor extended down to the second and third metacarpal heads and was treated with a multistaged excision of his tumor to achieve negative margins under slow Mohs micrographic surgery.

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

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare, low-grade mesenchymal skin tumour, characterized by slow infiltrative growth and common local recurrence, with infrequent distant metastases.

OBJECTIVE

The aim of this study is to better clarify clinicopathological characteristics of this tumour and to evaluate the cure rates of Mohs Tübingen technique (MTT) and wide local excision (WLE). Eventually, we perform a literature review to compare our experience with published data.

METHODS

A retrospective review was conducted on 135 patients diagnosed, treated and followed up between 1997 and 2014 at two different institutions. Sixty-two patients underwent to WLE and 73 to MTT. The primary end-points were the following: percentage of recurrences, time to progression and recurrence annual risk rate. Then, the PubMed database was searched for DFSP case series treated with standard surgical resection (SSR), WLE, Mohs' micrographic surgery (MMS) and MTT. The annual risk rate of recurrence calculated and reported for the four separate procedures was pooled to compare them.

RESULTS

Five of the 62 patients with WLE (8.1%) experienced recurrences after a mean follow-up of 4.7 years; the percentage of recurred patients 9 years after MTT was 5.5%, and the annual recurrence risk rate of 0.6%. Pooling these data with those from literature, the recurrence rate varies from 26% to 60% for SSR, from 0% and 41% for WLE, from 0% and 8.3% for MMS and from 0% to 5.5% for MTT. The lowest annual recurrence risk rate was found for MTT.

CONCLUSION

Significantly lower recurrence rates were recorded in patients treated with classic or Tübingen Mohs' technique. To the best of our knowledge, our case series is the widest treated with MTT ever described in the literature; these data may be useful to guide clinicians in the choice of the gold standard treatment for Dermatofibrosarcoma protuberans.

Incidence and Clinical Features of Rare Cutaneous Malignancies in Olmsted County, Minnesota, 2000 to 2010

BACKGROUND

The incidence of rare cutaneous malignancies is unknown. Current estimates of rare cutaneous malignancy incidences are based on broad epidemiologic data or single institution experiences, not population-based data.

OBJECTIVE

To determine the incidence of several rare nonmelanoma skin cancers.

MATERIALS AND METHODS

The authors conducted a retrospective chart review of a population-based cohort between the years 2000 and 2010. Residents of Olmsted County, Minnesota, who were diagnosed with a biopsy-proven nonmelanoma skin cancer-excluding basal cell carcinoma and squamous cell carcinoma-were included in this study. The primary outcome was tumor incidence. Additionally, the authors extracted patient demographics, tumor characteristics, treatment modalities, and outcomes.

RESULTS

The age-adjusted and sex-adjusted incidences per 100,000 persons of multiple rare cutaneous malignancies were: atypical fibroxanthoma (1.8), sebaceous carcinoma (0.8), dermatofibrosarcoma protuberans (0.4), microcystic adnexal carcinoma (0.7), eccrine carcinoma (0.4), eccrine porocarcinoma (0.2), and leiomyosarcoma (0.2).

CONCLUSION

The authors report population-based incidences and clinical characteristics for these rare cutaneous malignancies. The immune status and smoking status of patients and the treatment and outcomes of these tumors are reported. Additional studies in a broader population are needed to further define the epidemiology and outcomes of these malignancies.

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.

A single-institutional review of 68 patients with dermatofibrosarcoma protuberans: wide re-excision after inadequate previous surgery results in a high rate of local control

Background

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous soft tissue sarcoma characterized by an indolent but aggressive local growth. Unplanned excisions with positive margins are common, and the prognostic impact of radical re-excisions is still unclear. The aim of the present study was to identify prognostic indicators of recurrence-free survival (RFS) in patients with DFSP through a long-term follow-up. We tried particularly to determine the prognostic impact of surgical margins and re-excisions in patients after earlier inadequate surgery.

Methods

Seventy-five patients with DFSP were treated surgically at our institution between 1999 and 2015. Analyses were restricted to 68 participants with available information on surgical margins. The median follow-up was 5.4 years.

Results

Fifty-four patients (79.4%) had low-grade DFSP and 14 patients (20.6%) intermediate-grade FS-DFSP. The 5-year RFS rates were estimated to be 93.5% (95% CI 81.2–97.9) for low-grade DFSP and 39.7% (95% CI 13.0–65.8) for FS-DFSP (P < 0.0001). Re-excisions were performed in 55 patients (80.9%) following R1 or marginal R0 resections. Negative margins could be attained in a total of 65 patients (95.6%). Negative margin widths >1 cm led to the best local outcome within the R0 subgroup. Significant adverse prognostic features in the multivariate analysis included histologic grade and close margins.

Conclusions

The data from this study underscore the long-term benefit of negative margins. In our analysis, re-excisions were an effective method to achieve a high rate of local control in patients who presented after R1 or marginal R0 resection. To ensure the best outcome, re-excisions should aim at negative margin widths of more than 1 cm in the histologic specimen.

Nodular Fasciitis Complicating a Staged Surgical Excision of Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans (DFSP) is an unusual spindle cell tumor with a high rate of local recurrence with traditional excision. Fortunately, Mohs micrographic surgery yields excellent cure rates for this neoplasm due to contiguous tumor spread and meticulous tumor mapping and margin analysis. We present the unique case of a patient treated with a modified Mohs technique with an analysis of the final margin with permanent sections, who developed a spindle cell neoplasm in the margins of her second stage excision consistent with nodular fasciitis. Distinguishing residual DFSP from a benign reactive process was an essential and challenging component of this patient's management.

Reconstructive strategies for dermatofibrosarcomas of the face: role of regenerative dermal templates

BACKGROUND

Dermatofibrosarcomas protuberans is a challenging cutaneous tumor from an oncologic and reconstructive surgical point of view. Involvement of functionally and aesthetically sensitive areas, such as facial units, in young patients accounts for more demanding cases. An updated evaluation of most beneficial excisional/reconstructive strategies in these cases is still lacking.

METHODS

We investigated the potential of regenerative dermal templates in staged postoncologic reconstructive management of a young woman affected by a dermatofibrosarcomas protuberans of the forehead involving the frontal bone.

RESULTS

Final result was optimal in terms of cosmetic and functional recovery, obtaining a pliability, softness, and color similar to surrounding healthy skin.

CONCLUSION

In facial dermatofibrosarcomas protuberans, staged reconstruction with regenerative dermal templates provides a conservative yet safe and effective management, achieving optimal aesthetic outcomes. We suggest its adoption as first-line treatment in facial dermatofibrosarcomas protuberans that cannot be repaired by direct suture and in equivalent benign yet challenging cases.

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 in childhood treated with slow Mohs micrographic surgery

Dermatofibrosarcoma protuberans (DFSP) in childhood is a rare tumor with high recurrence rates. Wide local excision can result in disfiguring mutilation, whereas Mohs micrographic surgery (MMS) reduces surgical margins. MMS in children is not performed routinely, as the required infrastructures such as a histopathology lab in close proximity to the operating room is often lacking. We retrospectively reviewed children diagnosed with DFSP treated at our hospital over 2 years. We recorded surgical treatment details, including margins, duration of inpatient stay, outcome, follow-up, and molecular genetic tumor tissue analysis. Four children with a median age of 6.8 years (range 6.0-8.8 years) were identified who had a diagnostic delay of a median of 2.5 years (range 0.5-4.0 years); all underwent complete tumor excision using the slow MMS technique using vacuum-assisted closure systems between repeated excisions and before wound closure. The median maximal safety margins were 1.5 cm (range 1.0-3.0 cm). By using vacuum-assisted closure systems, no dressing changes were needed, pain was limited, and full mobility was maintained in all children. The median total time in the hospital was 11 days (range 10-14 days). No relapses occurred during a median follow-up of 25.8 months (range 11.3-32.6 months). Collagen 1A1/platelet-derived growth factor B (COL1A1/PDGFB) translocation on chromosomes 17 and 22 was detected in all three analyzable specimens. Lesions suspected of being DFSP warrant prompt histologic evaluation; interdisciplinary management is mandatory in particular for children. Micrographic surgery allows smaller surgical margins than wide excision and should be considered as the treatment of choice in children with DFSP. The interim usage of vacuum-assisted closure systems increases patient comfort. Translocations in the COL1A1/PDGFB gene imply susceptibility to targeted treatment modalities for therapy-resistant cases.

Atrophic dermatofibrosarcoma protuberans: report of a case demonstrated by detecting COL1A1-PDGFB rearrangement

Dermatofibrosarcoma protuberans is a locally aggressive mesenchymal neoplasm. It usually presents as an indurated plaque that protrudes above the surface of the skin. Some patients have clinically persistent plaques that might be atrophic. The atrophic variant of dermatofibrosarcoma protuberans may be confused with some common skin diseases with atrophic appearance. We reported a 40-year-old woman who had a 10-year history of an atrophic dermatofibrosarcoma protuberans. Molecular analysis showed a fusion between COL1A1 exon 31 to exon 2 of PDGFB. The lesion was totally excised, with negative margins of the resection demonstrated by CD34 immunostaining. To our knowledge, this is the second case of atrophic dermatofibrosarcoma protuberans confirmed by detection of COL1A1-PDGFB fusion gene. This appears to be the first report of a fusion between COL1A1 exon 31 to exon 2 of PDGFB in atrophic dermatofibrosarcoma protuberans.

Epidemiology of dermatofibrosarcoma protuberans in Alberta, Canada, from 1988 to 2007

BACKGROUND

There have only been a few population-based, epidemiologic studies assessing dermatofibrosarcoma protuberans (DFSP).

OBJECTIVE

To assess the epidemiology of DFSP in Alberta, Canada, over a 20-year period.

METHODS

A population-based, retrospective analysis of all cases of DFSP in Alberta was conducted using data from the Alberta Cancer Registry. Sex-, age-, and anatomical location-specific incidence rates and trends were determined.

RESULTS

The overall age-standardized incidence rate of DFSP remained stable at 0.93 per 100,000. DFSP prevalence was highest in individuals aged 20 to 39 (46.8%), followed by those aged 40 to 59 (34.0%), 60 and older (14.7%), and lastly younger than 20 (4.5%). The mean age at diagnosis was 41.1 (women) and 43.1 (men). The incidence of DFSP in men and women has shown a dramatic shift such that incidence in women has increased 3.2% per year, whereas in men it has decreased 2.7% per year. In women, DFSP incidence increased on the trunk and decreased on the upper extremities.

CONCLUSION

The age-standardized incidence of DFSP observed is nearly twice as high as previously reported and has remained stable. The incidence is increasing in women and decreasing in men. DFSP primarily affects young to middle-aged adults and most commonly presents on the trunk.