Dermatofibrosarcoma Protuberans: A Clinicopathologic and Therapeutic Analysis of 254 Cases at a Single Institution

Dermatofibrosarcoma Protuberans: A Study of 148 Patients

INTRODUCTION

Dermatofibrosarcoma protuberans (DFSP) is the most common sarcoma of the skin. Although distant metastases are infrequent, DFSP is highly aggressive locally with frequent local recurrences. It has been reported that the presence within the tumour of areas histopathologically mimicking fibrosarcoma may increase the risk of recurrence.

OBJECTIVE

The objective of this study was to review the clinical features of our patients with DFSP and the factors associated with recurrence of the tumour, focussing on the presence of fibrosarcomatous areas.

METHODS

Retrospective study of patients with DFSP diagnosed in 1990-2021 in a tertiary university hospital. The medical records were reviewed to obtain the following data: age, sex, tumour location, diameter, evolution time, presence of fibrosarcomatous areas, development of recurrence, and follow-up. Factors possibly associated with disease-free survival were analysed with Kaplan-Meier method and multivariate Cox regression.

RESULTS

148 patients (74 women/74 men, mean age 46.28 years, SD 14.431) were included in the study. Tumours involved the head and neck in 15 cases, thorax in 31, abdomen in 16, upper back in 43, lower back in 10, upper extremities in 10, and lower extremities in 23. Fibrosarcoma-like areas were observed in 16 tumours (10.81%). In 17 patients (11.49%), recurrences were observed (13 local recurrences, 3 lung metastasis, and 1 local recurrence with lung metastasis). Fibrosarcomatous DFSP recurred more frequently than classic DFSP (50% vs. 6.82%, respectively), and its disease-free survival was significantly lower (p < 0.001). In multivariate Cox regression, the presence of fibrosarcomatous areas was the only factor influencing disease-free survival.

CONCLUSIONS

It is important to identify the fibrosarcomatous variant since it recurs more frequently and has lower recurrence-free survival. Distant metastases, mainly in the lung, are also more frequent in fibrosarcomatous DFSP.

Surgery for primary malignant tumors of the abdominal wall: experiences of three African surgical oncology units and review of the literature

BACKGROUND AND OBJECTIVES

Tumors of the abdominal wall are uncommon but diverse. The surgical challenge is double. The tumor must be completely removed and the abdominal wall repaired. Our aim was to describe the indications, techniques, and results of surgery on these tumors in an African context.

METHODS

Retrospective, multicentric and descriptive study conducted in three West African surgical oncology units. We included all abdominal wall tumors followed up between January 2010 and October 2022. Histological type, size, surgical procedure, and method of abdominal wall repair were considered. Survival was calculated using the Kaplan-Meier method and comparisons of proportions were made using the Student t test.

RESULTS

We registered 62 tumors of the abdominal wall and we operated on 41 (66.1%). The mean size of the tumors was 14.3 ± 26 cm. Dermatofibrosarcoma and desmoid tumor were present in 33 and 3 cases respectively. In 31.7% of cases in addition to the tumour, the resections carried away the muscular aponeurotic plane. Parietal resections required the use of a two-sided prosthesis in 6 cases. In 13 cases, we used skin flaps. The resections margins were invaded in 5 cases and revision surgery was performed in all of them. Incisional hernia was noticed in 2 cases. The tumor recurrence rate was 12.2% with an average time of 13 months until occurrence. Overall survival at 3 years was 80%.

CONCLUSIONS

Surgery is the mainstay of treatment for abdominal wall tumors. It must combine tumor resections and parietal repair. Cancer surgeons need to be trained in abdominal wall repair.

Pediatric dermatofibrosarcoma protuberans: A clinicopathologic and genetic analysis of 66 cases in the largest institution in Southwest China

Background

Dermatofibrosarcoma protuberans (DFSP) is an uncommon cutaneous tumor in children. Most published articles are sporadic or small series and lack systematically molecular analyses. The aim of our study is to better understand the clinicopathologic and genetic features of these rare lesions.

Methods

All patients diagnosed with DFSP aged ≤ 18 years were retrospectively reviewed from January 2006 to May 2022.

Results

A total of 66 cases (32 male and 34 female patients) were identified, with ages ranging from 0.3 to 18 years (median, 13 years). Tumor locations predominantly occurred on the trunk (38/66, 57.6%), followed by the extremities (20/66, 30.3%) and head/neck (8/66, 12.1%). Histological findings revealed classic (41/66, 62.1%), myxoid (4/66, 6.1%), pigmented (6/66, 9.1%), plaque-like (3/66, 4.5%), giant cell fibroblastoma (GCF; 6/66, 9.1%), and fibrosarcomatous (6/66, 9.1%) variants of DFSP. Immunochemistry revealed minority tumors (9/66, 13.6%) showing patchy or negative staining for CD34. Fluorescence in situ hybridization (FISH) indicated that 49 of 53 tested cases including all detected biopsy specimens (11/11) contained COL1A1-PDGFB fusion, in which the average copy number gain of COL1A1-PDGFB was 0.68. There were four cases negative for COL1A1-PDGFB rearrangement, one of which was found to harbor a novel COL3A1-PDGFB fusion by next-generation sequencing (NGS). Treatment for 63 patients comprised 40 marginal excisions and 23 wide local excisions (WLEs), including 1 with imatinib therapy. Follow-up information was available on 49 patients with a duration of 12-161 months (median, 60 months). Fourteen patients developed tumor recurrence, all with initial marginal excisions. The others survived with no evidence of disease.

Conclusions

This study of pediatric DFSP indicates certain discrepancies in clinicopathologic characteristics between children and adults. The majority of pediatric DFSPs contain COL1A1-PDGFB fusion, the same as their adult counterparts. The COL3A1-PDGFB chimerism might be associated with the special morphology of GCF, which needs further investigation. FISH is valuable in biopsy tissues and cases with atypical CD34 immunostaining, while supplementary NGS could be helpful to identify the cytogenetically cryptic DFSP. Overall, an urgent accurate diagnosis is needed to formulate an optimal therapeutic strategy in the pediatric population.

Dermatofibrosarcoma protuberans surgery: Experiences of four African surgical oncology units and literature review

BACKGROUND AND OBJECTIVES

Dermatofibrosarcoma is a locally malignant tumor. This gives surgery a place of choice. The advent of imatinib has improved outcomes. Our aim is to describe the indications, techniques and results of surgery.

METHODS

A retrospective, multicenter, descriptive study conducted in four West African surgical oncology units. It covers dermatofibrosarcoma surgery performed between January 1, 1988 and December 31, 2020. We took into account the surgical procedure, the mode of skin coverage, adjuvant treatments and survival. Comparisons were possible using Student's t-test and Pearson's χ² .

RESULTS

We recorded 81 cases of dermatofibrosarcoma. Surgery was effective in 90.1% of cases. Wide resection was the principle with a mean resection margin of 3.8 ± 1.9 cm. healing by primary intention, flaps and healing by secondary intention were the methods of skin coverage in 30.1%, 24.7% and 41.1% respectively. The type of skin coverage was related to the topography and size of the tumor (p < 0.0001). The healing time is associated with the type of skin cover. The recurrence rate was not related to the type of skin coverage (p = 0.8).

CONCLUSIONS

Wide and deep resection in the absence of Mohs micrographic surgery ensures healthy margins. Oncoplasty reduces the healing time without increasing the risk of recurrence.

Non-Melanoma Skin Cancer Mortality in Spain: A Predictive Model up to 2044

Non-melanoma skin cancers (NMSC) are the most common malignancies worldwide and are, worryingly, increasing in incidence. However, data in the literature on NMSC specific mortality are scarce, because these tumors are excluded from most mortality registries. The main objective of this study is to analyze NMSC’s mortality rates and use them to generate a predictive model for the coming years in Spain. Data on mid-year population and death certificates for the period 1979–2019 were obtained from the Spanish National Statistics Institute. The Nordpred program (Cancer Registry of Norway, Oslo, Norway) within statistical program R was used to calculate mortality adjusted rates, as well as the mortality projection with an age-period-cohort model. This is the first study to report a prediction about NMSC mortality in the next years. According to our findings, the number of NMSC deaths in older people will grow in both sexes, especially in those older than >85 years old (y.o.). The age-specific mortality rates of NMSC will tend to stabilize or gradually decrease, with the exception of women between 75–79 y.o., who will present a slight increase at the end of the period. Early prevention and screening of NMSC specifically oriented to this population might change this tendency.