Clinical variants of the preprotuberant stage of dermatofibrosarcoma protuberans

Non-protuberant Lesions and Diagnostic Delays in Dermatofibrosarcoma Protuberans: A Single Institutional Retrospective Analysis

Abstract is missing (Short communication)

Dermatofibrosarcoma Protuberans: An Updated Review of the Literature

Dermatofibrosarcoma protuberans (DFSP) is a rare proliferative condition representing skin sarcomas which is known to locally recur yet very rarely metastasizes. Its genetic background is a reciprocal translocation t(17;22)(q22;q13) that produces COL1A1-PDGFB gene fusion. Complete resection is the primary treatment. The aim of this review is to outline the pathogenesis, diagnosis, and management of DFSP. A clear-cut distinction between low-to-moderate-grade DFSP with excellent prognosis and high-grade fibrosarcomatous DFSP with a much worse prognosis is underlined. Malignant transformation within DFSP (or high histologic grade), older age, being female, large primary tumor size (≥10 cm), narrow surgical margins of excision (<3 cm), surgical margin positivity for tumor cells, short time to recurrence, numerous recurrences, tumor that was recently rapidly enlarging, and presence of pain in the tumor have all been proposed as clinicopathological risk factors for recurrence and metastasis. A tendency for local growth and local relapses of well- and moderately differentiated DFSPs is an argument for their surgical excision, possibly combined with reconstructive surgery, even in patients of advanced age. Another main point of this review is that cases of DFSP with fibrosarcomatous transformation are a challenge and require careful medical attention. Both anatomopathological evaluation of the presence of lymphovascular space invasion and sentinel lymph node biopsy at DFSP surgery merit further study.

Dermatofibrosarcoma protuberans in a pre-adolescent child

INTRODUCTION

Dermatofibrosarcoma protuberans (DFSP) is a rare skin sarcoma with a slow growth rate and less chance of metastasizing but it is associated with higher morbidity due to its aggressive nature of local infiltration and its recurrence nature.

IMPORTANCE

When dealing with DFSP in children we could achieve low morbidity with appropriate surgical planning and approach even though aggressive wide local excision was performed.

CASE REPORT

12-year boy presented with a lump in his left arm which was initially clinically and ultrasonically diagnosed as lipoma. However, histological examination, coupled with CD34 immunohistochemistry, confirmed the diagnosis as DFSP.

CLINICAL DISCUSSION

Modern microsurgical methods, such as Mohs micrographic surgery, are advocated as effective treatment options, their availability and feasibility may be limited in certain settings. Therefore, the classic approach of wide local excision remains the treatment of choice in the majority of cases, with radiotherapy recommended for recurrent disease. Proper patient education and regular surveillance will help identify recurrence in time which aids us to provide timely intervention and optimize outcomes for patients with dermatofibrosarcoma protuberans.

CONCLUSION

Accurate diagnosis using histology coupled with immunohistochemistry, proper surgical technique and regular follow up are the three pillars of managing DFSP.

Dermatofibrosarcoma protuberans in the breast: Case report

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The occurrence of dermatofibrosarcoma protuberans in the breasts is rare.

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Histological examination is helpful for identifying dermatofibrosarcoma protuberans.

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Treatment of dermatofibrosarcoma protuberans; surgical resection.

Introduction and importance

Dermatofibrosarcoma protuberans (DFSP) represents about 1% of soft tissue sarcomas with an estimated incidence of 0.8–5.0 cases per million per year. The involvement of DFSP in breast is very rare and very few cases have been reported in the literature. DFSP was recurred in situ, not spread to distant site. The complete surgical excision with wide, pathologically negative margins of 3 cms is the optimal treatment for primary or recurrent tumor.

Presentation of case

A 46-year-old woman presented with palpable lump in the in the right breast. On ultrasonography, a lesion appeared as hypoechoic, circumscribed mass of approximately 37 mm × 30 mm in diameter in the upper central part of the right breast. The mass of right breast was demonstrated DFPS by pathologic examination. Chest computerized tomography (CT) scan and 2-[18F]-fluoro-2-deoxy-d-glucose (18F-FDG) positron-emission tomography (PET) showed only primary lesion in subcutaneous layer and no enlarged lymph node. The patient underwent excision of the tumor widely. There was no evidence of DFSP local recurrence after five years of follow-up of the patient.

Discussion

DFSP is a rare tumor arising from dermis and subcutaneous mesenchymal tissue. Whereas, characteristic imaging feature of DFSP in the breast are not well-defined. The primary treatment for DFSP is considered to be surgical excision.

Conclusion

DFSP in breast is extremely uncommon and can mimic a primary breast tumor. Surgical excision with adequate resection margins is recommended to ensure local control of the disease.

Atrophic dermatofibrosarcoma protuberans: a clinicopathological study of 16 cases

We present a case series of atrophic dermatofibrosarcoma protuberans (DFSP) to further characterise its clinical and pathological features. Sixteen cases were enrolled in the study. There were five males and 11 females with a median age of 28 years. The vast majority occurred in the trunk (12/16, 75%), whereas a minority involved the upper limb or limb gird (2/16, 12.5%), and head and neck region (2/16, 12.5%). The most common presentation was a depressed plaque-like lesion with a greyish-red to purplish-blue colour. Histologically, the lesion was dermal-based consisting of monomorphous spindle cells arranged in parallel fascicles with focal areas displaying storiform architecture. In addition, one case showed remarkable hyalinisation of the matrix, two cases contained scattered pigmented dendritic cells and one case had admixed giant cell fibroblastoma-like component, respectively. The diagnosis was confirmed by immunohistochemical study, and by further fluorescence in situ hybridisation analysis in six cases. Follow-up thus far has revealed a relatively low rate of local recurrence (1/10, 10%). Familiarity with the distinctive clinical and pathological features of atrophic DFSP helps avoid misdiagnosis. Like a classical DFSP, morphological variants can also occur in an atrophic DFSP, including pigmented, sclerosing and hybrid subtypes, albeit rare.

Perspectives of Patients With Dermatofibrosarcoma Protuberans on Diagnostic Delays, Surgical Outcomes, and Nonprotuberance

IMPORTANCE

Dermatofibrosarcoma protuberans (DFSP) may have a deceptively benign clinical appearance, including a nonprotuberant presentation. Patients with DFSP often perceive misdiagnoses and delays in receiving a diagnosis. Use of existing, patient-designed Facebook patient support groups (FBSGs) to recruit large numbers of patients with rare diseases may be an effective novel research method.

OBJECTIVES

To collaborate with patients with rare disease through social media and answer questions important to both patients and the medical field, including sources of diagnostic delay, risk of recurrence, and flat presentation of DFSP.

DESIGN, SETTING, AND PARTICIPANTS

A multiple-choice survey created by a team of medical practitioners and patients with DFSP was administered to 214 patients with DFSP or family members from international DFSP FBSGs and a nonprofit foundation patient database via Lime Survey from October 30 to November 20, 2015. The survey asked questions designed to determine risk of recurrence and metastasis, surgical outcomes, sources of diagnostic delay, symptoms of recurrence, number of recurrences, scar size, and number of clinicians seen before biopsy. Statistical analysis was performed from January 1, 2016, to April 1, 2019.

MAIN OUTCOMES AND MEASURES

The study goal was to collect at least 200 survey responses.

RESULTS

Of 214 survey respondents (169 females and 45 males; mean [SD] age, 40.7 [12.1] years; range, <1 to 72 years), 199 were patients with DFSP and 15 were family members. Delays occurred between the patient noticing the DFSP lesion and receiving a diagnosis of DFSP (median, 4 years; range, <1 to 42 years). Most patients (112 [52.3%]) believed that they received a misdiagnosis at some point: by dermatologists (35 of 107 [32.7%]), primary care clinicians (80 of 107 [74.8%]), or another type of physician (27 of 107 [25.2%]). The most frequent prebiopsy clinical suspicion included cyst (101 [47.2%]), lipoma (30 [14.0%]), and scar (17 [7.9%]). Many patients first noticed their DFSP as a flat plaque (87 of 194 [44.8%]). Of these lesions, 73.6% (64 of 87) became protuberant eventually. Surgical treatments included Mohs micrographic surgery (56 of 194 [28.9%]), wide local excision (122 of 194 [62.9%]), and conservative excision (16 of 194 [8.2%]). The reported rate of recurrence was 5.4% (3 of 56) for Mohs micrographic surgery, 7.4% (9 of 122) for wide local excision, and 37.5% (6 of 16) for conservative excision. The higher rate of recurrence for conservative excision was significant (P = .001); there was no significant difference in the rate of recurrence between Mohs micrographic surgery and wide local excision (P = .76).

CONCLUSIONS AND RELEVANCE

This study reports what appears to be disease-relevant statistics from the largest survey of patients with DFSP to date. Because of the dissonance between the name of the neoplasm and its clinical presentation, the alternative term dermatofibrosarcoma, often protuberant is proposed. This study suggests that FBSGs are useful tools in medical research, providing rapid access to large numbers of patients with rare diseases and enabling synergistic collaborations between patients and medical researchers.

Dermatofibrosarcoma protuberans: clinicopathologic presentation in Nigerians

Introduction

Dermatofibrosarcoma protuberance (DFSP) is in general a rare low grade malignant sarcoma and possesses a tendency for local recurrence. It has a site predilection for the trunk. Occurrence in the facial area is extremely rare. Ample knowledge of its clinical, histological and biologic characteristics is vital for accurate and prompt recognition.

Methods

Over 13 years, clinicohistologic information of cases was retrieved. Histological and immunohistochemical re-evaluation were performed to re-confirm diagnosis. Data collected and analyzed with SPSS Statistics version 20 were presented as frequency tables, charts and proportions as appropriate.

Results

Of 191 soft tissue sarcomas, a total of 28 cases were diagnosed as DFSP (14.7%). Facial types occurred in 3 cases (1.6%). Tumour had age and site predilections for the 4^th decade and trunk respectively. There was an equal gender distribution among cases. Most common clinical presentation was in form of painless protruding nodular mass. General histologic presentation revealed cellular lesions composed of spindle to oval neoplastic cells arranged in a storiform pattern. Mitotic figures were rare. All cases showed positive expressions to CD34.

Conclusion

Facial DFSP is rare among Nigerians. Its clinical appearance may mimic other common benign lesions of the head and neck region often resulting in misdiagnoses. A comprehensive knowledge of its clinical and histologic presentations and biologic behavior, combined with its identification with the aid of advanced histologic and radiographic techniques results in prompt confirmatory diagnosis. Appropriate treatment should include adequate surgical excision techniques combined with adjuvant radiotherapy or chemotherapy.

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.

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.

Histologic Features Associated with Deep Invasion in Dermatofibrosarcoma Protuberans

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing cutaneous tumor that can invade the subcutaneous tissue, muscle tissue, and even bone.

OBJECTIVE

To identify histologic features associated with greater depth of invasion, i.e., local aggressiveness, in DFSP.

MATERIAL AND METHODS

We analyzed associations between histologic features of DFSP (e.g., type of subcutaneous invasion, histologic pattern, cell type, areas of fibrosarcoma) and the presence and absence of muscle fascia involvement.

RESULTS

We studied 155 cases of DFSP. The following histologic characteristics were significantly associated with involvement of the muscle fascia: the presence of a sheetlike pattern, a high degree of cellular pleomorphism, and more than 1 mitotic figure. The tumor did not extend beyond the subcutaneous tissue in the majority of cases (62.6%), but there was involvement of the fascia or galea aponeurotica in 17 cases (11%) and of the muscle tissue in 36 cases (23.2%).

CONCLUSIONS

Histologic patterns, degree of pleomorphism, and number of mitotic figures are important predictors of deep invasion (fascia or muscle) in DFSP; these layers can be involved in up to 30% of cases.

Dermatofibrosarcoma protuberans with pit-like lesions: A case report and literature review

The present study describes a case of pit-like dermatofibrosarcoma protuberans (DFSP) with the clinical manifestations, histopathological features and criteria for diagnosis. The study also reviews the relevant literature in order to raise awareness among dermatologists with regard to the specific behavior of DFSP. A 27-year-old female presented with subcutaneous nodules on the left side of the neck that had been apparent for 5 years and which had gradually begun caving in during the last year. Histopathological examination revealed that the tumor was composed of a large number of spindle cells arranged in a whirlpool-like pattern. Immunohistochemical studies revealed positive staining for cluster of differentiation 34, vimentin and lysozyme, which could be used as diagnostic markers of DFSP. The patient was finally diagnosed with DFSP by pathological and immunohistochemical analyses. The DFSP was treated with an extended resection followed by adjacent skin repair. The patient responded well and no relapse occurred during the 8-month clinical follow-up. Thus, the current study describes a unique pit-like clinical manifestation of DFSP with typical immunohistochemical and pathological features. In addition, histopathological examination revealed a downward depression in the epidermis. Therefore, histopathological examination should be considered as an essential diagnostic tool for DFSP.

Dermatofibrosarcoma protuberans: from translocation to targeted therapy

Dermatofibrosarcoma protuberans (DFSP), the most common dermal sarcoma, is a low-grade, slow growing fibroblastic malignant neoplasm that most frequently affects middle aged adults and is characterized by a high local recurrence rate and a low propensity for metastasis. Wide surgical resection or Mohs micrographic surgery (MMS) are the preferred approaches for localized disease, while radiation therapy is warranted for inoperable disease or for cases with positive margins where re-excision is not possible. DFSP is generally regarded as refractory to conventional chemotherapy. Treatment options for systemic disease were limited until the discovery of a unique translocation, t(17;22)(q22;q13) (COL1A1;PDGFB) found in a majority of cases. In recent years, imatinib, a PDGFβR, ABL and KIT inhibitor, has revolutionized systemic therapy in DFSP. In this review, we summarize the epidemiological, clinical, histological and genetic characteristics of DFSP and update the readers on its current management.

[Dermatofibrosarcoma protuberans: report of 38 cases]

Le dermatofibrosarcome protubérans de Darier et Ferrand est une tumeur cutanée rare. Le but de cette étude est de décrire les aspects épidémiologiques, cliniques, histologiques, thérapeutiques et évolutifs avec comparaison aux données de la littérature. Il s'agissait d'une étude rétrospective sur 10 ans à propos de 38 cas de dermatofibrosarcome de Darier et Ferrand pris en charge à l'Institut National d'Oncologie. Les données épidémiologiques, diagnostiques, thérapeutiques et évolutives ont été recueillies à partir des dossiers cliniques des patients et rapportées sur une fiche préétablie. L’âge médian des patients était de 41,5 ans. Tous les patients avaient une preuve histologique de dermatofibrosarcome. Seulement 30 patients ont été traités à l'Institut National d'Oncologie. L'exérèse chirurgicale de la tumeur était large, avec des marges de sécurité de 6-10 cm chez 6 patients (20%), 5 cm chez 16 patients (53%), 2-3 cm chez 4 patients (13%). En profondeur, l'exérèse emportait une barrière anatomique saine. 5 malades ont bénéficié d'une radiothérapie externe avec une dose médiane de 59,5 Gy. Le recul médian était de 64,4 mois (28- 138 mois). Le dermatofibrosarcome protubérans de Darier et Ferrand est une tumeur se distinguant par son évolution lente, son agressivité locale, son haut pouvoir de récidive et la rareté des métastases. Le traitement consiste en une exérèse large et profonde. Le pronostic dépend essentiellement de la qualité de l'exérèse initiale chirurgicale. La série étudiée présente des similitudes épidémiologiques, cliniques, et thérapeutiques avec les données de la littérature.

Surgical Treatment of Dermatofibrosarcoma Protuberans Using a Reversed Adipofascial Sural Flap - Case Report

Dermatofibrosarcoma protuberans is a rare superficial tumor characterized by high rates of local recurrence and low risk of metastasis. Dermatofibrosarcoma protuberans occurs most commonly on the trunk and proximal extremities, it affects all races, and often develops between the second and the fifth decade of life. The tumor grows slowly, typically over years. We present a rare case of a young male patient, 21 years old, with an asymptomatic calf tumor which was suspected to be an angioma, but after the initial excision histology and imunohistochemistry proved to be a Dermatofibrosarcoma protuberans without safety limits. After 2 weeks, we excised the remaining scar with 4 cm tissue limit and the defect was covered using an adipofascial reversed sural flap from the posterior part of the left calf and after another 2 weeks we applied a skin graft from the thigh. The patient had a good evolution, with full recovery, without local recurrences or metastasis, and the histology was within good safety limits.

Photoletter to the editor: Atrophic dermatofibrosarcoma protuberans with minimal clinical manifestation

Dermatofibrosarcoma protuberans is an uncommon soft tissue neoplasm. In the vast majority of cases it presents as a nodule or a firm tumor that can reach massive dimensions producing the protuberant nodules for which it is named. We report a case of a 34-year-old woman presented at our department with an 8-year history of a small and discretely erythematous supraclavicular atrophic plaque. Skin biopsy lead to the diagnosis of dermatofibrosarcoma protuberans and a wide local excision of the tumor was performed in collaboration with the Plastic Surgery department. In this clinical case we describe an uncommon variant of the disease with minimal clinical manifestation that can cause serious diagnostic difficulties. The small and discrete atrophic plaque of our patient could have been easily ignored with serious clinical and prognostic implications for the patient.

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

BACKGROUND

For the treatment of dermatofibrosarcoma protuberans (DFSP), wide surgical excision has been recommended, with 3-5-cm margins, including the first underlying clear fascia. Since 2006, a technical improvement in pathological analysis called the vertical modified technique (VMT) has allowed us to reduce the surgical margin without increased oncological risk.

METHODS

Between 2006 and 2011, 66 cases of DFSP were analysed in our hospital, using VMT. We reviewed patient records, considering the initial margin, total margin, number of surgeries and outcomes. Functional and aesthetic consequences were assessed by the surgeon and by the patients.

RESULTS

Mean initial margin for the first resection was 18 mm (10-30 mm). First resection allowed complete resection of the tumour in 52 cases (78.8%). Mean total surgical margin was 21.3 mm (10-60 mm). There were no cases of local tumour recurrence at a median follow-up of 30 months. Reconstruction was performed using direct sutures in 53 cases (80.3%), split-thickness skin grafts in six cases (9.1%), full-thickness skin grafts in five cases (7.6%) and flaps in two patients (3%). For 90.9% of the patients, the aesthetic result was acceptable, whereas 84.8% patients were satisfied with the functional result.

CONCLUSION

VMT reduces surgical margins and allows for extensive analysis of margins. This technique represents a safe and reliable strategy in DFSP, without increasing the risk of recurrence. The outcomes of our study have confirmed the data from the literature regarding oncological safety.

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.

Dermatofibrosarcoma protuberans: Our experience of 59 cases

Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue tumor with intermediate malignancy. It is initially located on the skin from where it is able to infiltrate the deep structures and has a tendency to recur locally following inadequate excision. A t(17;22)(q22;q13) chromosome trans-location is the main cytogenetic alteration responsible for the onset of DFSP. Treatment options include complete surgical excision by performing conventional surgery with wide margins (>3 cm) or Mohs micrographic surgery. A retrospective study was conducted in our Department of Plastic and Reconstructive Surgery and all data were collected from medical records of 59 DFSP patients within this department from 1999 to 2011. A total of 13 of 59 (22%) cases were treated with conventional excision; 3 (5%) cases resulted in tumor-free margins, 8 (14%) cases required surgical revision and 2 (3%) cases lead to recurrence. A total of 46 of 59 (78%) cases were treated with wide excision; 43 (73%) cases resulted in tumor-free margins, 3 (5%) cases required surgical revision and 0 (0%) cases lead to recurrence. In conclusion, the data collected reveal the controversy surrounding the adoption of general guidelines regarding safe margins. Further studies are required to investigate the possibility of obtaining genotypically altered margins from margins that may appear phenotypically healthy.

Dermatofibrosarcoma protuberans of the breast skin

A case of a 26-year-old woman with dermatofibrosarcoma protuberans of the breast skin is described. She had noticed a palpable mass with redness 15 years previously, but it had begun to grow rapidly with swelling and redness two months before presenting. Ultrasonography and biopsy demonstrated a possibility of sarcoma of the breast. Wide excision was performed to confirm the diagnosis. Histologically, the tumor was composed of a uniform population of fibroblasts in a distinct storiform pattern. CD34 immunostaining showed diffuse reactivity. Platelet-derived growth factor β break-apart fluorescence in situ hybridization analysis showed a split-signal pattern which supported the diagnosis of dermatofibrosarcoma protuberans in the skin of the breast. It is important to diagnose a soft tissue lesion accurately when it occurs in the breast.

Plaque-like CD34-positive dermal fibroma ("medallion-like dermal dendrocyte hamartoma"): clinicopathologic, immunohistochemical, and molecular analysis of 5 cases emphasizing its distinction from superficial, plaque-like dermatofibrosarcoma protuberans

Medallion-like dermal dendrocyte hamartoma (DH) and superficial (plaque-like) dermatofibrosarcoma protuberans (DFSP) are CD34-positive dermal neoplasms with overlapping clinicopathologic features. We analyzed the clinical, histomorphologic, and molecular criteria of 5 DH and 7 DFSP to delineate diagnostically relevant differences between incipient dermal DFSP and its benign look-alike, DH. We expand the clinical and histologic spectrum of DH. As medallion-like dermal DH is neither of dermal dendrocyte lineage nor a genuine hamartoma, we propose instead the descriptive term of plaque-like CD34-positive dermal fibroma (PDF). Both PDF/DH and DFSP presented as slightly pigmented and indurated plaques on neck, trunk, and extremities. Histologically, DFSP was characterized either by horizontally oriented spindle cell fascicles or by diffusely arranged fibroblasts within a slightly myxoid stroma in the upper two-thirds of the dermis, whereas PDF/DH presented with a cellular band-like fibroblastic proliferation mostly in the papillary and adjacent upper reticular dermis. Only one congenital PDF/DH in a 9-year-old boy extended into the septa of the subcutaneous fat. Formalin-fixed paraffin-embedded archival tissue was used for detection of the COL1A1-PDGFB gene rearrangement by multiplex reverse transcription-polymerase chain reaction (RT-PCR) and by dual color fusion fluorescence in-situ hybridization (FISH). Archival blocs older than 4 years did not yield amplifiable RNA because of RNA degradation, whereas FISH analysis was feasible in all investigated cases. FISH analysis revealed COL1A1-PDGFB gene rearrangement in all DFSP cases (n=7), whereas RT-PCR could detect the COL1A1-PDGFB fusion transcript only in 1 DFSP. Two cases were negative. In 4 archival cases with storage between 4.5 and 12 years, RNA had been degraded making these cases unsuitable for RT-PCR. In PDF/DH, both RT-PCR and FISH analysis did not reveal any evidence of COL1A1-PDGFB gene rearrangement. We show that PDF/DH and superficial (plaque-like) DFSP, subtle clinicopathologic differences notwithstanding, are morphologic look-alikes that can be kept apart by molecular studies of the COL1A1-PDGFB gene fusion. For the detection of the COL1A1-PDGFB gene rearrangement in diagnostically difficult cases, RT-PCR and FISH analysis are reliable and helpful diagnostic tools. In archival formalin-fixed paraffin-embedded tissue, however, FISH analysis is more robust and exhibits a higher clinical sensitivity than RT-PCR.

Dermatofibrosarcoma protuberans of the breast: mammographic, ultrasound, MRI and MRS features

Dermatofibrosarcoma protuberans (DFSP) of the breast is a rare malignant tumor, and its preoperative diagnosis is extremely difficult. Local recurrence of DFSP is frequent after incomplete resection because of either false diagnosis or inadequate standard surgical excision. We present a case of DFSP that showed disconcordant results using different imaging modalities, suggesting that the MRI finding of subcutaneously located highly vascular tumor with suspicious kinetics but together with negative Cho peak on (1H) MRS, might be suggestive of the diagnosis of DFSP.

Dermatofibrosarcoma protuberans: recent clinical progress

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous tumor of low malignant grade characterized by a pattern of slow, infiltrative growth and a marked tendency to recur locally after surgical excision. Wide surgical resection is generally accepted as optimal treatment for DFSP. However, despite optimal surgical management, distant metastases may develop in up to 5% of patients. More than 90% of DFSP are characterized by a reciprocal chromosomal translocation, t(17;22). This rearrangement leads to constitutive activation of the platelet-derived growth factor receptor (PDGFR) as a result of deregulated ligand expression, thus providing a rationale for targeted inhibition of PDGFR as a treatment strategy for patients with unresectable locally advanced or metastatic DFSP.

METHODS

This article reviews the current understanding of DFSP, with emphasis on molecular-level pathogenetic events and their implications for management, and evidence for the role of tyrosine kinase inhibition in improving the outcomes of patients with unresectable locally advanced or metastatic DFSP.

RESULTS

Surgery with wide margins remains the cornerstone in the management of DFSP. Recently, imatinib, a potent, selective inhibitor of the PDGFR alpha and PDGFR beta protein-tyrosine kinases, has been reported to induce complete or partial remissions in most patients treated for advanced DFSP.

CONCLUSIONS

Imatinib is approved for treatment of adult patients with unresectable, recurrent, and/or metastatic DFSP who are not eligible for surgery. Future investigations will determine whether imatinib can also be used in the neoadjuvant setting to reduce tumor volume, thereby allowing resection of very large DFSP that would otherwise not be resectable.

Dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is a soft tissue neoplasm of intermediate malignancy that is initially localized to the skin from where it can invade deep structures (fat, fascia, muscle and bone). It is the most frequent fibrohistiocytic tumor, comprising approximately 1.8 % of all soft tissue sarcomas and 0.1 % of all cancers. It has an estimated incidence of 0.8-5 cases per one million persons per year. Treatment of localized disease consists in complete surgical excision of the lesion by conventional surgery with wide margins (>3 cm) or by micrographic Mohs surgery. Although the cases of metastatic DFSP do not reach 5 % of the total, almost all of them appear after previous local relapses. The prognosis for metastatic cases is very poor with a survival of less than 2 years following detection of metastatic disease. Patients with locally advanced DFSP are not candidates for an initial radical surgical therapy therefore neoadyuvant treatment is required prior to surgery in order to reduce tumor burden. In this regard, chemotherapy and radiotherapy have not been highly efficacious so it is necessary to consider new alternatives. The demonstration of the oncogenic power of the translocation COL1A1-PDGFB in DFSP has allowed the successful introduction of drug therapy with antagonists of the PDGFB receptor for metastatic or locally advanced cases.

Dermatofibrosarcoma protuberans: a population-based cancer registry descriptive study of 66 consecutive cases diagnosed between 1982 and 2002

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year.

OBJECTIVE

To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002.

METHODS

Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied.

RESULTS

The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable.

CONCLUSION

Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating.