Subcutaneous dermatofibrosarcoma protuberans, a rare subtype with predilection for the head: A retrospective series of 18 cases

Head-and-neck dermatofibrosarcoma protuberans: Survival analysis and Clinically relevant immunohistochemical indicators

BACKGROUND

Head and neck dermatofibrosarcoma protuberans (HNDFSP) is extremely rare and not entirely understood.

OBJECTIVE

To investigate the clinicopathological features of HNDFSP and identify the expression of its clinically relevant indicators, with the expectation of improving the existing treatment strategies.

METHODS

A long-term follow-up of patients with HNDFSP who received treatment between 2000 and 2021 at Shanghai Ninth People's Hospital was conducted. The clinical, histological, and immunohistochemical data of the patients were retrieved and analyzed. The endpoint of the study was the incidence of significant disease-related clinical events (recurrences or metastasis).

RESULTS

A total of 49 patients with HNDFSP were included in the study, with males (92.7%) predominating than females (7.3%). Eighteen patients developed recurrent disease (36.8%) after surgery, and the median time of recurrence was 48 months (interquartile, 20-74 months). Metastasis occurred in two cases (4.1%). Two patients died during follow-up, both with local recurrence, and one of them with intestinal metastasis. Post-operation radiotherapy was administered to eight patients (16.3%) and the effect in local control was remarkable. Age, tumor size, and negative margins with sufficient safety width were the main independent factors affecting the disease-free survival. Several potential targeted therapeutic indicators, including EZH2 (80.0%), EGFR (91.4%), PDGF (97.1%), PD-L1 (77.1%), and VEGF (77.1%), were positively expressed in most tumor samples.

CONCLUSION

HNDFSP is rare, significantly challenging to control locally, and has a worse prognosis with current treatment strategies. Wide local excision and long-term follow-up are needed. Radiotherapy could improve the prognosis of patients with HNDFSP.

Gluteal Mystery: A Case Report of Superficial CD34-Positive Fibroblastic Tumor

The case at hand involves a 25-year-old woman suffering from a gradual enlargement of a gluteal mass over a five-year period. This rare medical condition is classified as superficial CD34-positive fibroblastic tumor (SCPFT), an intermediate form of mesenchymal malignancy, originally identified in medical literature in 2014. Initial physical examination revealed a 10 x 10 cm lump in the right upper gluteal region. Magnetic resonance imaging demonstrated a well-circumscribed lesion within the right gluteus maximus muscle. The patient had the lump removed surgically. Examination under a microscope revealed tumor cells with extensive pleomorphism, high cytokeratin (CK) and CD34 positivity, and a low Ki67 index, all of which are consistent with SCPFT. Postoperatively, the patient showed marked improvement, and ongoing monitoring was initiated due to the potential for local recurrence. This case reinforces the importance of considering SCPFT in the differential diagnosis of soft tissue masses, emphasizing the role of immunohistochemical staining in reaching a correct diagnosis. Given the rarity of SCPFT, more studies are necessary to refine our understanding and treatment approaches.

Dermatofibrosarcoma protuberans of the scalp: Surgical management in a multicentric series of 11 cases and systematic review of the literature

BACKGROUND

Dermatofibrosarcoma protuberans is a rare, slow-growing soft-tissue malignancy originating in the dermis that is characterized by an infiltrating growth pattern with a marked tendency of local recurrence. Complete surgical resection with pathological margin clearance must be achieved to reduce the risk of tumor recurrence. Resulting defects often require extensive reconstructive procedures. Dermatofibrosarcoma protuberans of the scalp poses particular challenges owing to the proximity to the face and brain. This study aims to evaluate treatment options and proposes an algorithm for management of scalp dermatofibrosarcoma protuberans based on a multicentric case series and systematic review of the literature.

METHODS

A retrospective multicentric chart analysis of 11 patients with scalp dermatofibrosarcoma protuberans who presented within the last 20 years was performed regarding demographic data, pathological tumor characteristics, and surgical management (resection and reconstruction). Additionally, a further 42 patients (44 cases) were identified through a systematic Preferred Reporting Systems for Systematic Reviews and Meta-Analysis-based review of the literature searching the Medline and Embase databases.

RESULTS

In total, 30 cases were classified as primary and 20 cases as recurring scalp dermatofibrosarcoma protuberans (data from 5 cases were missing). The median tumor size was 24 cm2 (interquartile range 7.8-64), and the median defect size was 55.8 cm2 (interquartile range 48-112). Recurring scalp dermatofibrosarcoma protuberans was more often associated with invasion of deeper layers and required more extensive tumor resection to achieve negative margins. Within the subgroup that was managed with peripheral and deep en face margin assessment, no recurrence was observed. Most patients required local (41. 8%) or free flap (27.8%) reconstruction after dermatofibrosarcoma protuberans resection.

CONCLUSION

Whenever possible, peripheral and deep en face margin assessment-based techniques should be preferred for resection of scalp dermatofibrosarcoma protuberans because they provide superior oncological safety while preserving uninvolved tissue. Patients with locally advanced and recurring scalp dermatofibrosarcoma protuberans often require multidisciplinary treatment including neurosurgery, radiotherapy, and microvascular reconstructive surgery and should be referred to a specialized center.

Molecular Characterization of Dermatofibrosarcoma Protuberans: The Clinicopathologic Significance of Uncommon Fusion Gene Rearrangements and Their Diagnostic Importance in the Exclusively Subcutaneous and Circumscribed Lesions

The clinicopathologic relevance of various gene rearrangements underlying dermatofibrosarcoma protuberans (DFSP) remains insufficiently characterized. In 188 DFSPs, we determined PDGFB, COL1A1, PDGFD, COL6A3, and EMILIN2 rearrangements by fluorescence in situ hybridization (FISH). The clinicopathologic significance of rearrangement types and factors related to recurrence and metastasis were statistically analyzed. In all, classic PDGFB rearrangement, cryptic COL1A1-PDGFB fusion, and PDGFD rearrangement were identified in 172 (91.4%), 8 (4.3%), and 8 (4.3%: 4 COL6A3-PDFGD, 4 EMILIN2-PDGFD) cases, respectively. In an index DFSP harboring the cryptic fusion, the COL1A1-PDGFB transcript was confirmed by both RNA sequencing and reverse transcription-polymerase chain reaction. In comparison with cases harboring classic PDGFB rearrangement, cryptic PDGFB-rearranged DFSPs usually exhibited higher 5'-COL1A1 copy numbers. In a combined reappraisal of published and current cases, COL6A3-PDGFD-positive DFSPs (n=16) predominated in females (n=14, 88%) and torso (n=14, 88%), especially the breast (n=7, 44%); EMILIN2-PDGFD-positive DFSPs (n=6) preferentially demonstrated near exclusively subcutaneous growth (n=5, 83%) and fibrosarcomatous transformation (n=5, 83%). In our cohort, local recurrence was related to fibrosarcomatous variant (P=0.029, odds ratio=3.478) and head and neck location (P=0.046, odds ratio=3.508). Distant metastasis only occurred in the fibrosarcomatous variant (9/73, 12.3%) but not in other cases. In conclusion, 8.6% of DFSPs are negative for PDGFB break-apart FISH, which, especially those with challenging subcutaneous and circumscribed manifestation, require complementary diagnosis by FISH assays targeting COL1A1 and PDGFD. The types of fusion gene rearrangements, head and neck location, and fibrosarcomatous transformation may account for clinicopathologic and prognostic variations in DFSPs and warrant future independent validation.

Determination of Margins for Tumor Clearance in Dermatofibrosarcoma Protuberans: A Single-Center Study of 222 Cases Treated With Modified Mohs Surgery

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is an invasive skin tumor traditionally associated with very high recurrence rates when treated with conventional surgery (CS).

OBJECTIVE

To calculate the minimum margin that would have been required to achieve complete tumor clearance with hypothetical CS. To analyze DFSP characteristics and Mohs micrographic surgery (MMS) effectiveness in treatment of this tumor.

MATERIALS AND METHODS

Minimum margin was calculated by measuring the largest distance from the visible edge of the tumor to the edge of the surgical defect. Tumor variables (age, sex, size, time since onset, and location) were correlated with surgical variables (number of stages and minimum margin).

RESULTS

We studied 222 cases of DFSP treated with MMS. A mean of 1.47 MMS stages and a mean minimum margin of 1.23 cm were required to achieve tumor clearance. Tumors on the head and neck required significantly more stages and a significantly wider margin. Tumor size was positively correlated with time to diagnosis, age, and number of MMS stages.

CONCLUSION

Tumors located on the head and neck have greater subclinical extension. Tumor size was also a predictor of surgical difficulty, but time to diagnosis was not.

Systematic review of Mohs micrographic surgery in children: Identifying challenges and practical considerations for successful application

BACKGROUND

Few data exist to guide the application of Mohs micrographic surgery (MMS) in the pediatric population.

OBJECTIVE

We sought to summarize the clinical characteristics of children undergoing MMS, identify challenges that limit the use of MMS in this population, and examine how these challenges can be overcome.

METHODS

A systematic review of PubMed and EMBASE, from inception of databases to November 2, 2019, identified all cases of pediatric skin lesions treated with MMS.

RESULTS

A total of 111 patients were included. The median patient age was 11 years (range 6 weeks to 17 years). The most commonly treated tumor was dermatofibrosarcoma protuberans (n = 62), followed by basal cell carcinoma (n = 30). The most common location was the head and neck (n = 34), followed by the trunk (n = 28) and the extremities (n = 23). The most commonly cited challenges in the application of MMS in children included patient cooperation, concerns for the safety of prolonged general anesthesia, availability of a MMS service in the pediatric setting, and access to a histopathology laboratory experienced in MMS sectioning.

LIMITATIONS

Many articles did not report specific patient characteristics.

CONCLUSION

Multiple obstacles limit the application of MMS in pediatric patients. This review describes practical methods to circumvent these obstacles to facilitate the appropriate use of MMS in children.

Superficial CD34-Positive Fibroblastic Tumor: Report of an Extremely Rare Entity

Superficial CD34-positive fibroblastic tumor (SCPFT), a newly described neoplasm is a rare mesenchymal neoplasm of intermediate malignancy. A 63-year-old man presented with a painless, slow-growing, skin-colored nodule of 8 × 4 mm in diameter on the right side of the neck. It was completely resected. Histologically, a tumor located in the subcutis with the minimally infiltrative pattern was detected. The tumor was composed of variably enlarged bizarre and pleomorphic spindle to polygonal cells. Tumor cells were stained strongly diffuse positive with CD34 and weak positive with keratin, negative with STAT6, FLI-1, ERG, S100, desmin, and smooth muscle actin. The fluorescence in-situ hybridization (FISH) analysis was negative for COL1A1 gene rearrangement. As per the findings, the case was diagnosed as a SCPFT. It is a borderline mesenchymal neoplasm occurring within the superficial soft tissues with distinctive morphological and immunohistochemical features.

The efficacy of Mohs micrographic surgery over the traditional wide local excision surgery in the cure of dermatofibrosarcoma protuberans

Usually most patients with dermatofibrosarcoma protuberans (DFSP) may present rather late when the tumor is in protuberant phase due to its rarity and indolent onset. It has a high propensity for local recurrence and destructive nature. Management of DFSP requires a biopsychosocial and Multidisplinary approach regardless of the clinical or immunohistochemical variant. Surgery is the Gold standard management of localized disease. DFSP rarely exhibits any lymphatic or hematogenous dissemination. It is because of its high recurrence rate associated with Wide Local Excision (WLE), the introduction of Mohs micrographic surgery (MMS) has really helped in reducing the rates of recurrence of DFSP. Thus, the aim of this meta-analysis and systemic review is to advocate for MMS over WLE for DFSP and other cutaneous malignancies using DFSP as a prototype. The objective of this study were to conduct a meta-analysis on comparative surgical methods used in the cure of DFSP with regards to WLE verses MMS, to evaluate the cure rates with relation to recurrence rates, offer a recommendation on the various treatment modalities based on the location of lesion, and use of adjuvant therapy in different clinical-medical setups. A comprehensive retrospective analysis search in EMBASE, Google Scholar and Medline (PubMed) for studies published from 2008 to 2018 containing the surgical management of DFSP with WLE verses MMS were reviewed. Five studies of moderate-quality evidence (level B) with a pooled patient load of 684 was analyzed and found for recurrence of DFSP after WLE and MMS to be 9.10% and 2.72% respectively after an average follow-up time for both groups of 5.32 years with a female predominance of 1.58. The trunk is the commonest site for the DFSP lesion which was at 52.80% then the upper and lower extremities zones and the head and neck zones at 31.75% and 15.45% respectively. The pooled adjusted odds ratio (OR) analysis indicated that there was a direct relationship with regards the reduced recurrence rate of DFSP in the MMS group compared to the WLE group (OR:0.31;95%; CI :0.17-0.56). Furthermore, there was significant association between the reduced recurrence rate with the MMS in DFSP patients with a statistical P-value of 0.0001 at 95% CI. The expected increased recurrence rate by zones was in WLE head and neck zone at 38.19% then trunk and extremities zone at 13.34%. In the MMS group it was at of 23.4% as compared to 16.0% in the head and neck zone. Mohs Micrographic Surgery (MMS) is more efficacious in the cure rate and recurrence reduction of DFSP and should be advocated for as first line therapy especially in high recurrence prone zones.

Dermatofibrosarcoma protuberans: our 10-year experience on 80 patients

Background: Dermatofibrosarcoma protuberans (DFSP) is a rare soft tissue sarcoma. Its high recurrence rate is a clinical challenge.Objective: To analyze DFSP clinicopathologic factors and review our experience of treatments.Materials and methods: A total of 80 patients who were treated between 2007 and 2017 in Shanghai Ninth People's Hospital were evaluated. Outcomes were compared focusing on recurrence following different treatment methods. Classical DFSP and transformed DFSP were classified as the two subtypes.Results: The recurrence rate after local excision was significantly higher than that after wide margin excision. Patients undergoing wide margin excision (margins over 3 cm) were found to have lower recurrence rate compared with those margins less than 3 cm, while 10 underwent Mohs surgery were not found recurrence. Transformed DFSP had a greater tendency to recur.Conclusions: Clean margin of excision should be achieved to prevent recurrence of DFSP. Slow Mohs surgery is recommended to treat DFSP.

S1 guidelines for dermatofibrosarcoma protuberans (DFSP) - update 2018

While dermatofibrosarcoma protuberans (DFSP) is a rare cancer entity overall, it is nevertheless the most common type of cutaneous sarcoma. The tumor is of fibroblastic origin and characterized by slow, undermining and locally destructive growth. Metastatic spread is very rare. Given its nonspecific clinical appearance, diagnosis is frequently delayed. Biopsy and subsequent histopathology are key diagnostic tools. Standard treatment for primary tumors consists of complete excision with surgical margins of 1 to 2 cm. Smaller margins are associated with high local recurrence rates. Inoperable and metastatic DFSP may be treated with radiation therapy. Approximately 80-90 % of DFSP lesions harbor a fusion gene that results in continuous activation of the PDGF-β signaling pathway. Consequently, molecular targeted therapy inhibiting PDGF-β is an effective option for advanced (inoperable) and metastatic DFSP. The first agent to be approved for systemic treatment of DFSP is the multikinase inhibitor imatinib, showing objective response rates of about 50 % in clinical trials.

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.