Dermatofibrosarcoma protuberans in children: an update on the diagnosis and treatment

Comprehensive analysis of transcriptome characteristics and identification of TLK2 as a potential biomarker in dermatofibrosarcoma protuberans

Background: Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous sarcoma characterized by local invasion and recurrence. RNA sequencing (RNA-seq) allows the qualification of cellular RNA populations and provides information on the transcriptional state. However, few studies have comprehensively analyzed DFSP transcriptional data.

Methods: Fourteen DFSP samples with paired non-neoplastic soft tissue from Chinese patients undergoing Mohs micrographic surgery were used for RNA-seq analysis. Differential expression analysis and enrichment analysis for RNA-seq data were performed to identify fusion genes, biomarkers, and microenvironment characteristics of DFSP.

Results: This study systemically describes the transcriptomic characteristics of DFSP. First, we performed gene fusion analysis and identified a novel FBN1-CSAD fusion event in a DFSP patient with fibrosarcomatous transformation. Then, we identified TLK2 as a biomarker for DFSP based on functional enrichment analysis, and validated its accuracy for diagnosing DFSP by immunohistochemical staining and joint analysis with public data. Finally, microenvironment analysis described the infiltration characteristics of immune and stromal cells in DFSP.

Conclusion: This study demonstrates that RNA-seq can serve as a promising strategy for exploring molecular mechanisms in DFSP. Our results provide new insights into accurate diagnosis and therapeutic targets of DFSP.

Dermatofibrosarcoma: Case Report Series

Dermatofibrosarcoma protuberans (DFSP) is an uncommon, painless, slow-growth, superficial soft tissue malignant sarcoma corresponding to less than 0.1% of all malignancies. The primary treatment for DFSP is surgical excision, which is wide local excision (WLE) with tumor-free margins, Mohs micrographic surgery (MMS), and partial or total amputation. The goal of surgical excision is to achieve negative resection margins, thus reducing the local recurrence rate. These three cases reported large dermatofibrosarcoma, which began as a small nodule and progressed within approximately a year and were treated subsequently with wide excisions surgery. The unique and challenging part for most surgeons is removing the mass with a concentric excision due to its specific growth pattern. To achieve negative resection margins, the width of the tumor-free margins and infiltrating depth are two essential factors to be considered for complete excision for both WLE and MMS surgical techniques. Adjuvant therapy, including radiotherapy and targeted therapy, is reserved for unresectable, advanced stage, or recurrent tumors.

Diagnostic and Management Considerations in Pediatric Dermatofibrosarcoma Protuberans

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare fibrohistiocytic tumor of dermal origin. Six percent of all cases present in children, with a childhood incidence of 1 per million.

METHODS

This is a retrospective review of all cases of pediatric DFSP managed at a single institution over a 23-year period.

RESULTS

Seventeen patients (10 male; mean age, 9.9 years) were managed during the study period. The median follow-up was 29 months. All patients had surgical excision. Three patients required further excision to achieve uninvolved final margins. There were no recurrences observed.

CONCLUSIONS

Pediatric DFSP should be managed by a soft tissue tumor multidisciplinary team, with experienced pathologists and reconstructive surgeons. Where R0 resections are obtained, patients can experience recurrence-free survival.

Multicentric dermatofibrosarcoma protuberans in a child with severe combined immunodeficiency due to adenosine deaminase deficiency

We report the case of a 4-year-old boy, post-human stem cell transplantation for severe combined immunodeficiency (SCID) due to adenosine deaminase deficiency (ADA), who developed multiple dermatofibrosarcoma protuberans (DFSP). We hypothesize a role for chimerism leading to accumulation of toxic metabolites which can cause DNA strand breaks and inhibit lymphocyte activation. Patients with ADA-SCID should remain under lifelong dermatologic surveillance as DFSP lesions can be quite inconspicuous.

Dermatofibrosarcoma protuberans: the diagnosis of high-grade fibrosarcomatous transformation

OBJECTIVES

Dermatofibrosarcoma protuberans (DFSP) is an intermediate-grade tumour which may undergo fibrosarcomatous transformation to a high-grade sarcoma (DFSP-FST). DFSP-FST requires wide local resection, and therefore, pre-operative identification is important. The aims of this study are to see if DFSP and DFSP-FST can be differentiated based on MRI appearances, and to determine the ability of ultrasound-guided core needle biopsy (US-CNB) to identify DFSP-FST.

MATERIALS AND METHODS

Retrospective review of patients with a histological diagnosis of DFSP with/without transformation to DFSP-FST. Patient age, gender, lesion location and maximal size were recorded, as were several MRI features. MRI studies were reviewed independently by 2 musculoskeletal radiologists and the assessed features were then compared with final surgical resection histology. Histological results of US-CNB were also compared with final surgical pathology.

RESULTS

A total of 42 patients were included, 26 males and 16 females with a mean age of 41.3 years (range 3-78 years). The upper limb was involved in 12 cases, the lower limb in 17 and the trunk in 13. Final surgical histological diagnosis was DFSP in 21 (50%) cases and DFSP-FST in 21 (50%) cases. Mean tumour dimension for DFSP was 32 mm and DFSP-FST 68 mm (p < 0.001). MRI features indicative of DFSP-FST included multi-lobular morphology (p = 0.03), T2W hypointensity compared with fat (p = 0.03), internal flow voids (p = 0.03) and peri-tumoral oedema (p < 0.001). Only 3 cases of DFSP-FST were correctly diagnosed on US-CNB.

CONCLUSIONS

Various MRI findings can suggest a diagnosis of DFSP-FST, but US-CNB is unreliable at identifying high-grade fibrosarcomatous transformation.

Dermatofibrosarcoma Protuberans: Update on the Diagnosis and Treatment

Dermatofibrosarcoma protuberans (DFSP) is a slow growing, low- to intermediate-grade dermal soft-tissue tumor. It has a high local recurrence rate but low metastatic potential. It is characterized by a uniform spindle cell arrangement, classically with a storiform pattern and CD34 immunoreactivity. The histomorphology and immunophenotype overlap with a broad range of other neoplasms. The standard treatment is complete surgical excision. The surgical procedures include wide local excision (WLE) with tumor free margins, Mohs micrographic surgery (MMS) and amputation. Unresectable DFSPs are treated with radiation therapy and/or targeted therapy. DFSP has characteristic t(17; 22) (q22; q13), resulting in a COL1A1- PDGFB fusion transcripts in more than 90% of DFSPs. Molecular detection of the gene rearrangement or fusion transcripts is helpful for the diagnosis of patients with atypical morphology and for screening candidates for targeted therapy with tyrosine kinase inhibitors. The aims of the present review are to update the clinical presentation, tumorigenesis and histopathology of DFSP and its variants for diagnosis and differential diagnosis from other benign and malignant tumors, to compare the advantages and drawbacks of WLE and MMS, to propose the baseline for selecting surgical procedure based on tumor’s location, size, stage and relationship with surrounding soft tissue and bone structures, and to provide a biologic rationale for the systemic therapy. We further propose a modified clinical staging system of DFSP and a surveillance program for the patients after surgical excision.

Dermatofibrosarcoma protuberans in children and adolescents: Primary and Relapsed disease-Experience of the Cooperative Weichteilsarkomstudiengruppe (CWS)

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare low-grade tumor. Little is known about best treatment of primary and relapsed disease (RD).

METHODS

Treatment and outcome of 40 patients with DFSP prospectively registered within the CWS-96 and -2002P trials and the registry SoTiSaR (1996-2016) were analysed.

RESULTS

Median age was 8 years (range, 0.64-17.77). Fluorescence in situ hybridization analysis to detect COL1A1-PDGFB fusion genes was positive in 86% (12/14) of evaluated patients. Primary resection was performed in all patients. Patients had IRS group I (n = 28), II (n = 9), and III (n = 2); not available (n = 1). To achieve complete remission (CR), a secondary resection was performed in 18 patients resulting in microscopically complete (R0, n = 34/40) and microscopically incomplete (R1, n = 5/40) resection. All patients achieved CR. The 5-year event-free survival (EFS) and overall survival was 86% (±12; CI, 95%) and 100% (±0; CI, 95%), respectively. R0 resection/IRS I was significantly favorable for the 5-year EFS. Local relapse occurred after a median time of 1.1 years (range, 0.04-5.1) in 15% (6/40) after CR. All patients with RD underwent resection and achieved CR. Three patients had fibrosarcomatous DFSP, two were alive after R0 resection.

CONCLUSION

Complete surgical resection is mandatory to prevent relapse of DFSP.

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.

Adenosine Deaminase (ADA)-Deficient Severe Combined Immune Deficiency (SCID): Molecular Pathogenesis and Clinical Manifestations

Deficiency of adenosine deaminase (ADA, EC3.5.4.4), a housekeeping enzyme of purine metabolism encoded by the Ada gene, is a cause of human severe combined immune deficiency (SCID). Numerous deleterious mutations occurring in the ADA gene have been found in patients with profound lymphopenia (T^- B^- NK^-), thus underscoring the importance of functional purine metabolism for the development of the immune defense. While untreated ADA SCID is a fatal disorder, there are multiple life-saving therapeutic modalities to restore ADA activity and reconstitute protective immunity, including enzyme replacement therapy (ERT), allogeneic hematopoietic stem cell transplantation (HSCT) and gene therapy (GT) with autologous gene-corrected hematopoietic stem cells (HSC). We review the pathogenic mechanisms and clinical manifestations of ADA SCID.

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.

Agminated Fibroblastic Conective Tissue Nevus: A New Clinical Presentation

Connective tissue nevi are benign hamartomatous lesions in which one or several of the components of the dermis (collagen, elastin, glicosaminoglycans) show predominance or depletion. Recently, de Feraudy et al broadened the spectrum of connective tissue nevus, describing fibroblastic connective tissue nevus (FCTN), which is characterized by proliferation of CD34(+) cells of fibroblastic and myofibroblastic lineage. Only solitary papules and nodules have been described. We present the first case of FCTN with multiple agminated lesions on the leg of an infant and the difficulties encountered in the differential diagnosis with dermatofibrosarcoma protuberans.

Dermatofibrosarcoma protuberans in pediatric patients: a report of 17 cases

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is an uncommon soft tissue tumor. In children, there are acquired and congenital presentations. Due to clinical similarities with other conditions, diagnosis may be delayed.

OBJECTIVE

To review the clinical characteristics and treatment of DFSP in pediatric patients.

METHODS

A retrospective chart review was performed from January 2002 to September 2012. Inclusion criteria were patients under 18 years of age with a histopathologic diagnosis of DFSP. Data on demographics, clinical characteristics, treatments, and outcomes were collected.

RESULTS

Information was gathered from 17 patients; 9 (53%) were female. Congenital lesions were reported in 7 patients. The mean delay of diagnosis was 5.7 years; the most common anatomic location was the trunk in 8 of 17 (47%) cases. Treatment options included wide local surgery, Mohs surgery, and imatinib mesylate.

CONCLUSION

A detailed medical history and identification of the natural course of common conditions seen in pediatric patients are important to identify less common lesions and to suspect DFSP.

Pediatric dermatofibrosarcoma protuberans in Madrid, Spain: multi-institutional outcomes

Little is known about the incidence and management of dermatofibrosarcoma protuberans (DFSP) in children. We conducted a retrospective review of all patients younger than 18 years of age treated for DFSP over a period of 11 years (2000-2011) in Madrid, Spain. The sample consisted of 13 children. The average annual incidence of DFSP in the pediatric population corresponded to 1.02 cases per million person-years (95% confidence interval 0.55, 1.73). Sites of involvement were diverse, with 15.3% of tumors found in acral locations. The median tumor size was 3.5 cm × 3 cm and the median time from apparent onset to diagnosis was 36 months. Histopathologic examination revealed conventional (77.0%), pigmented (15.4%), and myxoid (7.6%) variants. The mitotic index was consistently <5 per 10 high-power fields. All lesions were removed using surgical excision. One patient developed a local recurrence because of initial affected margins; none developed metastases. The median duration of clinical follow-up was 70.5 months. This study estimated the average annual incidence rate of DFSP in a population of patients younger than 18 years and reviewed the experience of several hospitals in the management of this tumor.

[What's new in oncology?]

In cutaneous oncology, the year 2012 was marked by the consolidation of earlier results as well as the emergence of new therapeutic perspectives. The consolidated results most notably concern the use of MAP-kinase inhibitors (anti-MEK, anti-BRAF) in the treatment of patients with metastatic melanoma. Vismodegib (an SMO inhibitor), used in the treatment of multiple basocellular carcinomas that are inoperable or that have developed in patients suffering from Gorlin syndrome, has been the subject of publication of large-scale studies. Of the new therapeutic advances, let us mention the use of inhibitors or monoclonal antibodies directed against the PD1 receptor and its ligand PD-L1, the combination of MEK and BRAF inhibitors in the treatment of metastatic melanoma, and treatment in adjuvant situations with these same inhibitors. Beyond these significant advances that must be credited to cutaneous oncology, new questions are emerging relative to the side effects observed with these targeted therapies. The onset of multiple epidermoid carcinomas or primary melanomas treated with BRAF inhibitors is a striking illustration of the paradoxes arising from the clinical transfer of scientific progress. The intellectual perspectives are therefore numerous. It is hoped that this work will succeed in making these innovative drugs available to the patients who will have contributed to their development through their participation in clinical trials.