Molecular pathways and therapeutic strategies in dermatofibrosarcoma protuberans (DFSP): unravelling the tumor's genetic landscape.

Dermatofibrosarcoma Protuberans (DFSP) is a rare soft tissue sarcoma distinguished by its infiltrative growth pattern and recurrence potential. Understanding the molecular characteristics of DFSP is essential for enhancing its diagnosis, prognosis, and treatment strategies. The paper provides an overview of DFSP, highlighting the significance of its molecular understanding. The gene expression profiling has uncovered unique molecular signatures in DFSP, highlighting its heterogeneity and potential therapeutic targets. The Platelet-Derived Growth Factor Receptors (PDGFRs) and Fibroblast Growth Factor Receptors (FGFRs) signaling pathways play essential roles in the progression and development of DFSP. The abnormal activation of these pathways presents opportunities for therapeutic interventions. Several emerging therapies, i.e., immunotherapies, immunomodulatory strategies, and immune checkpoint inhibitors, offer promising alternatives to surgical resection. In DFSP management, combination strategies, including rational combination therapies, aim to exploit the synergistic effects and overcome resistance. The article consisting future perspectives and challenges includes the discovery of prognostic and predictive biomarkers to improve risk stratification and treatment selection. Preclinical models, such as Patient-derived xenografts (PDX) and genetically engineered mouse models, help study the biology of DFSP and evaluate therapeutic interventions. The manuscript also covers small-molecule inhibitors, clinical trials, immune checkpoint inhibitors for DFSP treatment, combination therapies, rational therapies, and resistance mechanisms, which are unique and not broadly covered in recent pieces of literature. See also the graphical abstract(Fig. 1).

Current patterns of care and outcomes for dermatofibrosarcoma protuberans: An international multi-institutional collaborative.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a cutaneous sarcoma with an infiltrative growth pattern that makes it challenging to clear margins. High quality data regarding DFSP natural history, management, and outcomes are limited. METHODS: Data were retrospectively collected for adult DFSP patients who underwent resection at 10 institutions in eight countries. Demographics, tumor characteristics, treatment strategies, and outcomes were analyzed. RESULTS: Analysis included 347 patients consisting of young (median, 42 years), White (76.2%), males (54.2%) with truncal lesions (57.3%). The majority (76.8%) were symptomatic at presentation. Preoperative imaging was used in 55.9% of cases. Diagnosis was established with excisional biopsy in 50.9% versus incisional biopsy in 25.0% of cases. Despite planned margins of >1.0 cm in 67.4% of cases, only 69.0% of patients achieved R0 resection. Twenty-two percent of patients underwent at least one re-excision. R0 resection was achieved at a second procedure in 80.2% and a third procedure in 86.2%. Ultimately, R0 resection was feasible in 89.5% of all patients. Fibrosarcomatous transformation (FST) was observed in 12.6%. In total, 6.6% (N = 23) recurred (17 local, six distant). Of the six distant recurrences, 50.0% had FST. With a median follow-up of 47.0 months, disease-specific survival rate was 98.8%. In multivariable analysis, R0 margins at index resection were associated with wider circumferential margins and non-FST histology. CONCLUSIONS: In this international, multicenter collaborative, DFSP practice patterns were heterogeneous but achieved favorable recurrence rates and survival. Multiple excisions to clear margins remain commonplace and can inform future efforts to optimize margin selection.

Asymptomatic CD34+ plaque on the scalp of a child.

Fibroblastic connective tissue nevus (FCTN) is a rare, benign dermal mesenchymal lesion of fibroblastic and myofibroblastic lineage. We report a case of a 2-year-old male who presented with an 18-month history of an erythematous, asymptomatic, unchanging dermal plaque on the right medial frontal scalp. A punch biopsy showed a disorderly, bland, dermal fibroblastic spindle cell proliferation extending to the superficial subcutis. It stained positive for CD34, and concern for dermatofibrosarcoma protuberans was raised. However, FISH was negative for PDGFB rearrangement, and the constellation of findings was most consistent with FCTN. This case underscores the importance of distinguishing CD34+ mesenchymal tumors for both dermatologists and dermatopathologists. As these represent a rather diverse group of lesions with different biological behaviors, a knowledge of the differential diagnosis of these entities is critical for proper patient management.

Fibrosarcomatous Dermatofibrosarcoma Protuberans of the Head.

This article highlights the case of a 37-year-old male who presented with a recurrent, exponentially enlarging head mass, emphasizing the diagnostic and therapeutic challenges associated with a very rare type of tumor, fibrosarcomatous dermatofibrosarcoma protuberans (DFSP) of the head. Our patient presented with a rapidly growing head mass, initially diagnosed as a spindle cell tumor, and was managed with surgical excision and skin flap grafting. Follow-up revealed relapse and interval development of hemiparesis and hemisensory loss. MRI revealed tumor recurrence, with compression of the right parietal lobe and superior sagittal sinus. Histopathology revealed stroma with fascicles of spindle cells homogenous to fibrillar cytoplasm, with oval vesicular nuclei. Immunohistochemical staining showed positivity for CD34 and SMA. Oral chemotherapy with imatinib 800 mg/day was started. Follow-up imaging showed a marked reduction in the size of the tumor and resolution of the compression of the underlying brain parenchyma with cystic degeneration and decreased contrast enhancement. Future plans include possible surgical tumor debulking and/or radiation therapy. Although extremely rare, awareness of this tumor, with a multi-disciplinary approach to the management of the case, is vital to maximize treatment outcomes.

Metastatic Fibrosarcomatous Transformation of Dermatofibrosarcoma Protuberans With Lung Metastasis: A Case Report.

Dermatofibrosarcoma protuberans (DFSP) is a low- to intermediate-grade dermal soft tissue malignant tumor (sarcoma) with a high local recurrence rate but low metastatic potential. DFSP is characterized by uniform spindle cell fascicles arranged classically in a storiform pattern and by CD34 immunoreactivity. On gross examination, DFSP usually manifests as a white or yellow soft tissue mass with a smooth outer surface and poor circumscription. In this study, we report a case of DFSP with fibrosarcomatous transformation, a rare but well-known phenomenon encountered in DFSP that is correlated with an increased risk of adverse outcomes in patients with DFSP. A 45-year-old male presented with a progressively enlarging lump on his left shoulder, initially suspected of being a lipoma but diagnosed as a fibrosarcomatous transformation of DFSP. Surgical resection was performed, with the subsequent identification of metastatic sarcoma in pulmonary nodules. Robotic-assisted thoracoscopy excised the nodules, confirming metastatic sarcoma with aggressive behavior. Despite negative adjuvant treatment plans, the patient remains under surveillance with imaging, showing no recurrence in recent scans. Continued follow-up with medical and surgical oncology is planned. DFSP is a rare soft tissue sarcoma characterized by indolent growth and low metastatic potential, except in fibrosarcomatous transformation cases. Molecularly, DFSP is defined by a COL1A1-PDGFB fusion transcript that is targetable with imatinib therapy. Treatment involves wide surgical resection, with adjuvant radiation therapy in select cases. Radiation therapy may be employed in cases with close or positive margins, while conventional chemotherapy has limited utility. Multidisciplinary collaboration is crucial for optimal management. Overall, this case underscores the challenges in diagnosing and managing aggressive sarcomas like fibrosarcomatous DFSP, emphasizing the importance of vigilant surveillance and multidisciplinary collaboration in optimizing patient outcomes. Further research is needed to understand the mechanisms underlying fibrosarcomatous transformation and to explore novel therapeutic avenues for this challenging malignancy.

Darier-Ferrand dermatofibrosarcoma protuberans of the face: Case report and literature review.

INTRODUCTION: Darier Ferrand Dermatofibrosarcoma (DFSP) is a rare skin tumor, characterized by its local aggressivity and high potential of recurrence. It affects mainly young and middle-aged adults. Its location in the head and neck region represents nearly 12.5 % of all DFSP. CASE DESCRIPTION: We report a rare case of a 68-year-old patient who was treated for a DFSP of the cheek's lower part with reconstruction using a pectoralis major musculocutaneous flap. The postoperative course was uneventful and the aesthetic result was good. DISCUSSION: DFSP is a tumor of intermediate malignancy. Its optimal management is based on complete surgical excision requiring various reconstruction procedures for large defects. The treatment of unresectable lesions remains difficult despite the targeted therapies proposed and the improvement of radiotherapy techniques. CONCLUSION: The ideal management of a DFSP is based on surgical excision passing largely in healthy tissues. This situation requires early diagnosis and is the guarantee of disease-free survival without major sequelae in head and neck locations.

A challenging diagnosis of dermatofibrosarcoma protuberans of the middle finger in an infant: A case report.

INTRODUCTION: Dermatofibrosarcoma protuberans (DFSP) is a rare sarcoma, accounting for less than 0.1 % of tumors. While it predominantly occurs in adults, pediatric cases are unusual. This case report aims to highlight the diagnostic and therapeutic challenges posed by DFSP in infants due to its rarity and slow-growing nature, emphasizing the importance of early diagnosis and prompt intervention. CASE PRESENTATION: We report the case of an 8-month-old infant presenting with a progressive finger mass, initially mistakenly diagnosed as a dermatofibroma. Local excision was done, but the tumor recurred after one year. Subsequent re-excision and skin grafting were performed, and histopathology confirmed DFSP. Despite middle finger amputation three weeks later, a new mass emerged on the adjacent ring finger after one year. This tested negative for DFSP. The fibrous mass has persisted for five years without significant changes. CLINICAL DISCUSSION: DFSP is a rare sarcoma with a higher prevalence in adults. It typically presents as a painless, slow-growing mass and is usually diagnosed by biopsy and immunohistochemistry. Surgical excision with negative margins is the preferred treatment. The rarity and slow-growing nature of DFSP pose challenges in diagnosis and treatment. CONCLUSION: Early diagnosis and prompt surgical intervention are crucial in managing DFSP, especially given its high recurrence potential. Maintaining a high index of suspicion is essential even in very young children. Aggressive resection with negative margins and diligent post-operative surveillance are key strategies to mitigate metastasis risk and improve prognosis in such challenging cases.

The Epidemiology of Dermatofibrosarcoma Protuberans Incidence, Metastasis, and Death Among Various Population Groups: A SEER Database Analysis.

BACKGROUND: Limited information exists regarding the epidemiology, metastasis, and survival of dermatofibrosarcoma protuberans (DFSP). OBJECTIVE: To measure DFSP incidence and assess metastasis and survival outcomes. METHODS: Incidence rate, overall and DFSP-specific survival outcomes for primary DFSP tumors contained in the Surveillance, Epidemiology, and End Results registry (SEER) were analyzed via quasi-poisson regression, Cox and competing risk analyses. RESULTS: DFSP incidence rate was 6.25 (95%CI, 5.93-6.57) cases per million person-years with significantly higher incidence observed among Black individuals than White individuals (8.74 vs 4.53). DSFP with larger tumor size (≥3 cm, Odds ratio,OR,2.24,95%CI,1.62-3.12,p <0.001) and tumors located on the head and neck (OR: 4.88, 95%CI, 3.31-7.18, p<0.001), and genitalia OR:3.16,95%CI:1.17-8.52, p value=0.023) were associated with significantly increased risk of metastasis whereas higher socioeconomic status (SES) was associated with significantly decreased risk of metastasis. Larger tumor size (≥3 cm), regardless of location, and age (≥60) were associated with significantly worse overall and cancer-specific survival. LIMITATIONS: Retrospective design of SEER CONCLUSION: DFSP incidence is 2-fold higher among Black than White individuals. The risk of DFSP metastasis is significantly increased with tumor size ≥3 cm and tumors located on head and neck, and genitalia. Larger tumor size (≥ 3cm), regardless of location, and age (≥60) are the most important prognostic indicators for survival.

ALK-rearranged, CD34-positive spindle cell neoplasms resembling dermatofibrosarcoma protuberans: a study of seven cases.

AIMS: The majority of dermatofibrosarcoma protuberans (DFSP) harbour PDGFB or PDGFD rearrangements. We encountered ALK expression/rearrangement in a PDGFB/D-negative CD34-positive spindle cell neoplasm with features similar to DFSP, prompting evaluation of ALK-rearrangements in DFSP and plaque-like CD34-positive dermal fibroma (P-LDF). METHODS AND RESULTS: We searched the archives of academic institutions for cases previously coded as DFSP and P-LDF. NGS-naïve or PDGFB-negative DFSP were screened for ALK (clone D5F3) expression by immunohistochemistry. NGS or ALK FISH was performed on ALK-positive cases. Methylome profiling studies were performed and compared with conventional DFSP. One case of "DFSP" and two "P-LDF" with ALK expression were identified from the archives, while four cases were detected prospectively. These seven cases (6F:1M; 8 months to 76 years) arose in the dermis of the arm (two), scalp, eyelid, thigh, abdomen, and shoulder and ranged from 0.4 to 4.2 cm. Tumours were composed of spindled cells and displayed a storiform growth pattern. Cytologic atypia was absent, and mitotic figures were scarce (0-2/10 HPFs, high power fields). The lesional cells were diffusely positive for CD34 and ALK and negative for S100 protein. By NGS (n = 5), ALK fusion partners included DCTN1 (2), PLEKHH2, and CLIP2 in DFSP-like cases and FLNA in P-LDF-like lesions. ALK FISH was positive in one (of two) cases previously labelled P-LDF. Methylome profiling of two (of three) ALK-rearranged DFSP-like tumours showed clustering with conventional DFSP in the UMAP dimension reduction plot. To date, no tumour has recurred (n = 2; 26, 27 months). CONCLUSION: We describe a cohort of novel ALK-rearranged tumours with morphologic features similar to DFSP.

Analysis of surgical margins and prognostic factors in dermatofibrosarcoma protuberans after wide local excision: A multicenter study of 116 Japanese patients.

Cutaneous dermatofibrosarcoma protuberans (DFSP) is a fibrohistiocytic tumor characterized by a high risk of local recurrence but a low risk of metastasis. Wide local excision (WLE) has been an important treatment option, but its clinical outcomes and safety have not been thoroughly evaluated in previous reports. The aim of this study was to determine appropriate surgical margins (deep and lateral) and prognostic factors associated with recurrence-free survival (RFS) of DFSP. A database collected by two dermatology departments in Japan was retrospectively reviewed to identify 116 patients with DFSP who underwent complete resection with WLE between 1994 and 2021. Sixty-one men (53%) and 55 women (47%) were included in our cohort. The primary sites of DFSP were as follows: 11 head and neck (9%); seven face (7%); 12 upper extremities (10%); 20 lower extremities (17%); and 66 trunk (57%). There were 103 cases (89%) of primary DFSP and 13 cases (11%) of recurrent DFSP. Total 10-year RFS was 96.6%. There were significant differences in RFS by tumor size (median size: 3 cm), disease status (primary versus recurrent DFSP), and fibrosarcomatous change (positive versus negative) (all p < 0.05). Two patients (1.7%) with buccal or head lesions had positive deep margins. In all cases, the lateral margin was negative at the postoperative evaluation. Tumor size, disease status, and fibrosarcomatous change are important risk factors for recurrence. Both face and head-neck lesions were more likely to have positive deep margins than other anatomic areas in DFSP. Although this study was limited by its retrospective design, a narrow 2-cm lateral margin is especially considered for low-risk patients.

Fibrosarcomatous Transformation in Dermatofibrosarcoma Protuberans of the Male Breast and its Association with Magnetic Resonance Imaging and Immunohistopathologic Features.

BACKGROUND: Dermatofibrosarcoma Protuberans (DFSP) is a rare soft tissue sarcoma, accounting for approximately 1% of all tumors; however, DFSP of the breast is extremely rare. Moreover, DFSP generally has a low malignant potential and is characterized by a high rate of local recurrence along with a small but definite risk of metastasis. The risk of metastasis is higher in fibrosarcomatous transformation in DFSP than in ordinary DFSP. CASE REPORT: We have, herein, reported a case of a 61-year-old male patient with fibrosarcomatous transformation in DFSP. Preoperative Dynamic Contrastenhanced Magnetic Resonance Imaging (DCE-MRI) of the breast revealed an oval-shaped mass with heterogeneous internal enhancement, a large vessel embedded within, and a washout curve pattern on kinetic curve analysis. The mass exhibited a hyperintense signal on Diffusion-weighted Imaging (DWI), with a low apparent diffusion coefficient value. Histologically, the bland spindle tumor cells were arranged in a storiform pattern. Areas with the highest histological grade demonstrated increased cellularity, cytological atypia, and mitotic activity. Immunohistochemically, Ki-67 and p53 were highly expressed. CONCLUSION: Recognizing the risk and accurately diagnosing fibrosarcomatous transformation in male breast DFSP are critical for improving prognosis and establishing appropriate treatment and follow-up plans. This emphasizes the significance of combining immunohistopathological features with DCE-MRI and DWI to assist clinicians in the early and accurate diagnosis of sarcomas arising from male breast DFSP.

In vitro modeling of recurrent Dermatofibrosarcoma Protuberans: Assessment of 5-aminolevulinic acid photodynamic therapy efficacy.

BACKGROUND: Dermatofibrosarcoma Protuberans (DFSP) is a rare, low-grade malignant tumor of the dermis with a high recurrence rate post-surgery. Current treatments, including surgery, radiotherapy, and targeted therapy, have limitations. Photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) is a promising non-invasive approach, but its efficacy in DFSP treatment remains underexplored. METHODS: This study aimed to evaluate the anti-tumor efficacy of 5-ALA PDT using an in vitro model derived from a recurrent DFSP patient. The cells were treated with varying concentrations of 5-ALA and exposed to red light, followed by assessments of cell viability, proliferation, apoptosis, migration, invasion, angiogenesis, and expression of DFSP-related genes and proteins. RESULTS: 5-ALA PDT significantly reduced DFSP cell viability in a dose-dependent manner and induced apoptosis. It also effectively inhibited cell proliferation, migration, and invasion, as well as suppressed angiogenic activity in conditioned media. Furthermore, 5-ALA PDT downregulated the expression of COL1A1 and PDGFRB, key genes in DFSP pathogenesis. CONCLUSIONS: The findings provide the first evidence of 5-ALA PDT's in vitro anti-tumor efficacy against DFSP, suggesting its potential as a novel therapeutic approach for DFSP. Further studies are warranted to explore the clinical utility of 5-ALA PDT in preventing DFSP recurrence.

A Case Report of Dermatofibrosarcoma Protuberans and Refractory Hypomagnesemia: Unveiling a Paraneoplastic Syndrome.

Dermatofibrosarcoma protuberans (DFSP) is a rare, locally aggressive soft tissue sarcoma of the skin. DFSP typically presents as an asymptomatic, firm plaque in its earliest stage, gradually enlarging over months to years. This case report delineates a singular instance involving a 66-year-old female patient previously diagnosed with and treated for DFSP. The individual presented with a recurrent history of hospital admissions, manifesting symptoms of loose stools, generalised weakness, and diminished appetite. Investigations revealed persistent hypomagnesemia. The patient was treated with magnesium correction. Eventually, all complaints were resolved, and the patient was discharged satisfactorily. This case report aims to elucidate an exceptional correlation between DFSP and hypomagnesemia, characterised as its paraneoplastic syndrome (PNS). This study intends to comprehensively outline the clinical manifestations, diagnostic approaches, and therapeutic interventions pertaining to this distinct association.

Dermatofibrosarcoma Protuberans Arising From a Chronic Wound in the Left Shoulder: A Case Report.

Dermatofibrosarcoma protuberans (DFSP) is a rare, slow-growing soft tissue sarcoma, typically presenting as a cutaneous lesion. However, its occurrence in chronic wounds is infrequently documented, posing diagnostic and therapeutic challenges. This report details the case of a 59-year-old female with no significant medical history, presenting with a chronic, non-healing wound on the left shoulder, persisting for three years. Initially a small nodule, it progressed into an ulcerating lesion. Physical examination revealed a contracted scar with restricted shoulder mobility. After obtaining informed consent, a surgical excision of the lesion was performed by an electrocautery. Histopathology confirmed DFSP, characterized by spindle fibrous cells, with skin ulceration and deep dermal infiltration. A split-thickness skin graft achieved successful closure. This case underscores the importance of considering DFSP in chronic, non-healing wounds. Timely intervention and appropriate surgical management are crucial for favorable outcomes.

A novel method of assessing intraoperative surgical margins in patients with dermatofibrosarcoma protuberans: A specimen radiography system.

Background Dermatofibrosarcoma protuberans (DFSP) is one of the most challenging cutaneous cancers in surgical clinic practice. Excision with negative margins is essential for effective disease control. However, wide surgical margins and maximal tissue conservation are mutually exclusive. Mohs micrographic surgery conserves tissue but is time-consuming. Thus, we developed a novel specimen radiography system that can be used intraoperatively. Aims To introduce a specimen radiography system for evaluating intraoperative surgical margins in patients with dermatofibrosarcoma protuberans. Methods Since September 2017, we have treated seven biopsy-proven cases of local DFSPs via local excision with surgical margins of 2-4 cm. During operations, the operative specimens were screened using the specimen radiography system. All surgical specimens were pathologically examined intraoperatively. Results Five patients were men and two were women, of median age 36 years. The mean radiographic screening time was 9.7 ± 2.3 min. Radiographically negative margins were confirmed intraoperatively. The minimal margin width ranged from 5.0 to 35.4 mm (mean width 16.9 ± 10.4 mm). The intraoperatively negative radiographic margins were consistent with those revealed by postoperative pathology. The minimal pathological margin width ranged from 4.0 to 34.5 mm (mean 16.6 ± 10.1 mm) and was not significantly different from the intraoperative data. Limitations The sample size was small and positive or negative predictive values were not calculated. Conclusions We introduce a novel method of intraoperative surgical margin assessment for DFSP patients. It may find broad clinical and research applications during oncoplastic surgery.

Multiple primary dermatofibrosarcoma protuberans tumors in a single patient with chromosomal microarray analysis: A case report and review.

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous sarcoma with a high propensity for local invasion and recurrence. Although it is a rare event, the occurrence of multiple tumors in a single patient raises a diagnostic dilemma, as metastatic disease should be differentiated from multiple primary malignant events. In more than 90% of DFSP, a pathogenic t(17;22) translocation leads to the expression of COL1A1::PDGFB fusion transcripts. Karyotype analysis, fluorescence in situ hybridization, and RT-PCR can be useful ancillary studies in detecting this characteristic rearrangement, and sequencing of the fusion transcript can be used to support a clonal origin in metastatic and multifocal disease. However, previous reports have demonstrated variable sensitivity of these assays, in part due to the high sequence variability of the COL1A1::PDGFB fusion. Here, we report a patient who developed two distinct DFSP tumors over the course of 7 years. Chromosomal microarray analysis identified distinctive genomic alterations in the two tumors, supporting the occurrence of multiple primary malignant events.

A Case of Pan-TRK Positive Dermatofibrosarcoma Protuberans Located on the Nose.

Dermatofibrosarcoma protuberans (DFSP) is a rare and infiltrative soft tissue tumor. Our report details a distinctive case of DFSP with pan-TRK positivity in the right nasal dorsum of a 46-year-old female. Histological analysis identified NTRK fusion gene involvement in this patient, detectable through pan-TRK immunostaining. The case underscores the significance of comprehensive management for pan-TRK-positive DFSP in challenging facial locations, indicating the potential efficacy of TRK inhibitors.

Scrotal Dermatofibrosarcoma Protuberans in a Patient with Schizophrenia: A Case Report and Review of the Literature.

Dermatofibrosarcoma protuberans (DFSP) is a rare spindle cell soft tissue sarcoma of the dermis and subcutaneous tissue. We present the fourth case of scrotal DFSP in the literature, identified in a 32-year-old male with schizophrenia. Wide surgical excision and radical orchiectomy were performed revealing an uninvolved testicle and DFSP of the scrotum. A unique challenge to this case was concurrent aortic dissection and schizophrenia. Social determinants of health are associated with delay in presentation and poor appointment compliance in patients with schizophrenia. Ultimately, DFSP of the scrotum is an extremely rare condition with this presentation being only the fourth report in the literature. It is important to document these unique cases to establish differential diagnoses and optimize management.