Dermatofibrosarcoma Protuberans in Children

Dermatologic Review in Pediatric Vascular Lesions

Vascular anomalies (VAs) can be present in any organ; however, the skin being the largest one, it is there where many of them are evident; some are visible at birth, others develop throughout life. Pediatric dermatologists are specially trained to distinguish VAs from their mimickers, which require different treatments and may harbor distinct prognoses. We resume the diagnostic and therapeutic tasks of pediatric dermatologist at our vascular anomaly clinics, as well as the differential diagnoses of mimickers of VAs.

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 challenges: a case series and review of the literature

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is a rare variant of skin sarcoma which is characterized by proliferation of spindle cells in a storiform pattern. Although it is mostly benign in its primary stages, it can cause a high burden of morbidity unless it is thoroughly excised.

CASE PRESENTATION

Here, we review six cases of DFSP which were characterized by skin lesions in various parts of the body. Patients were from 26 to 51 years old; four were Asian men and two were Asian women. Wide surgical excision was performed for all these patients and no extra treatment was considered. Samples were studied by hematoxylin and eosin (H&E) staining and immunohistochemical (IHC) tests. Only one of our patients experienced recurrence after the initial surgery.

CONCLUSION

Determining the best surgical method is still a dilemma in the treatment of DFSP lesions. There are numerous studies to prove the efficacy of various surgical interventions. Although DFSP is not commonly known as a malignant skin lesion, delay in treatment will have a catastrophic impact on patients' lives. Thus, applying an in-time surgical method (wide local excision in our cases) in treating DFSP is crucial in preventing recurrence as well as decreasing the morbidity burden of DFSP.

Hybridtumor eines Riesenzellfibroblastoms und eines Dermatofibrosarcoma protuberans

Wir berichten über ein zum Zeitpunkt der Erstmanifestation 10 Monate altes Kind mit einem Hybridtumor aus Riesenzellfibroblastom (RZFB) und Dermatofibrosarkoma protuberans (DFSP). Das RZFB ist ein seltener Tumor, der mit dem DFSP die Translokation (t17;22) (q22;13) und immunphänotypische Eigenschaften teilt und daher von seinen Erstbeschreibern als kindliche Form des DFSP eingeordnet wurde. Das RZFB hat mit einer Kombination aus Spindelzellproliferaten, häufig hypozellulären Arealen mit kollagenfaserreichem oder myxoidem Stroma, sinusoid-artigen pseudovaskulären Aufweitungen zwischen den Kollagenfasern, die von multinukleären Riesenzellen umsäumt werden, jedoch ein ihm eigenes histologisches Bild. Das RZFB, das sich klinisch als langsam wachsende, i.d.R. schmerzlose Schwellung manifestiert, tritt präferentiell im Kindesalter auf. Das mittlere Erkrankungsalter liegt bei 6 Jahren. Die Therapie der Wahl ist die Exzision mit einem ausreichenden Sicherheitsabstand. Unsere junge Patientin zeigt ein Jahr nach Exzision mit 2 cm Sicherheitsabstand einen rezidivfreien Verlauf.