Dermatofibrosarcoma Protuberans

Dermatofibrosarcoma protuberans:
- Is an intermediate-grade sarcoma:
  - That presents as a unifocal or multifocal nodular lesion
- It is a rare, slow-growing, locally aggressive cutaneous sarcoma:
  - With a high rate of local recurrence and low metastatic potential
Dermatofibrosarcoma protuberans:
- Involves the head and neck region in 10% to 20% of cases:
  - With the scalp and supraclavicular fossae the most common sites for involvement (Figure)
These slow-growing, locally aggressive tumors have tentacle-like extensions well beyond the visible lesion:
- Thus the true extent of the disease is often underestimated:
  - Leading to local recurrence in more than 50% of patients
Histologically a storiform or fascicular proliferation of spindle cells extends
from the dermis into the subcutis:
- With immunohistochemistry showing:
  - CD34 positive staining in most cases
- Presence of fibrosarcomatous changes and high mitotic rate:
  - May portend a more aggressive course
- This tumor frequently has a translocation of a fusion protein involving:
  - COL1A1 and PDGFB that functions like PDGFB
Wide excision with margins of ≥ 2 cm is
generally advocated, with adjuvant radiation reserved for larger or recurrent tumors when resection is not feasible
Histological subtypes include:
- Classic DFSP
- Fibrosarcomatous transformation:
  - Conferring a higher risk of recurrence and metastasis
Surgical management is the mainstay of treatment:
- The National Comprehensive Cancer Network (NCCN), National Cancer Institute, and American Cancer Society recommend:
  - Mohs micrographic surgery (MMS) as the preferred approach due to its ability to achieve complete margin control and minimize tissue loss, especially in anatomically sensitive areas
  - If MMS is unavailable, wide local excision (WLE) with 2 to 4 cm margins down to the investing fascia is acceptable:
    - Achieving negative surgical margins is the most critical factor for reducing recurrence risk; margin width is important, but negative margins are paramount
  - Recent evidence suggests that margins greater than 2 cm to 2.5 cm are associated with significantly lower recurrence rates:
    - But recurrence is rare when negative margins are achieved, regardless of width
  - Routine lymph node dissection is not indicated for DFSP, as the risk of nodal metastasis is extremely low
  - Lymph node dissection should be considered only in cases with clinical or radiologic suspicion of nodal involvement or in tumors with fibrosarcomatous transformation, which carries a higher metastatic risk
  - Sentinel lymph node biopsy is not standard but may be considered in select high-risk cases, such as those with fibrosarcomatous change or lymphovascular invasion, though its utility remains under investigation
Adjuvant radiotherapy:
- Is considered in cases of positive or close margins when further re-excision is not feasible, or for unresectable or recurrent disease
- The role of adjuvant radiotherapy is supported by its ability to reduce local recurrence in these settings
Imatinib, a tyrosine kinase inhibitor:
- Is indicated for unresectable, recurrent, or metastatic DFSP harboring the t(17;22) translocation (COL1A1-PDGFB fusion)
Cytotoxic chemotherapy:
- Has a limited role and is generally reserved for metastatic disease not amenable to targeted therapy, with inferior outcomes compared to imatinib
Surveillance recommendations include:
- Regular follow-up for early detection of local recurrence:
  - Particularly within the first three years post-resection:
    - As most recurrences occur during this period
  - For patients with negative-margin, non-fibrosarcomatous DFSP:
    - Less intensive follow-up may be appropriate, and some data suggest that ongoing surveillance may not be necessary after negative-margin resection
  - In contrast, patients with fibrosarcomatous transformation should be followed according to soft tissue sarcoma protocols due to higher risk of recurrence and metastasis
Areas of ongoing debate include the optimal surgical margin width and the role of sentinel lymph node biopsy, particularly in high-risk subtypes:
- The consensus remains that complete surgical excision with negative margins is the cornerstone of management, with adjuvant therapies reserved for select cases
References:
- Dermatofibrosarcoma Protuberans: Update on the Diagnosis and Treatment. Hao X, Billings SD, Wu F, et al. Journal of Clinical Medicine. 2020;9(6):E1752. doi:10.3390/jcm9061752.
- Review of Dermatofibrosarcoma Protuberans. Lim SX, Ramaiya A, Levell NJ, Venables ZC. Clinical and Experimental Dermatology. 2023;48(4):297-302. doi:10.1093/ced/llac111.
  Dermatofibrosarcoma Protuberans: What Is This?. Vitiello GA, Lee AY, Berman RS. The Surgical Clinics of North America. 2022;102(4):657-665. doi:10.1016/j.suc.2022.05.004.
- Dermatofibrosarcoma Protuberans: An Updated Review of the Literature. Jozwik M, Bednarczuk K, Osierda Z. Cancers. 2024;16(18):3124. doi:10.3390/cancers16183124.
- Current Patterns of Care and Outcomes for Dermatofibrosarcoma Protuberans: An International Multi-Institutional Collaborative. Winer LK, Akumuo R, Fredette JD, et al. Cancer. 2025;131(1):e35468. doi:10.1002/cncr.35468.
- Surgical Management of Dermatofibrosarcoma Protuberans. Rust DJ, Kwinta BD, Geskin LJ, et al. Journal of Surgical Oncology. 2023;128(1):87-96. doi:10.1002/jso.27258.
- Dermatofibrosarcoma Protuberans. Miller SJ, Alam M, Andersen JS, et al. Journal of the National Comprehensive Cancer Network : JNCCN. 2012;10(3):312-8. doi:10.6004/jnccn.2012.0032.
- Oncological Efficiency of Wide Local Excision in Dermatofibrosarcoma Protuberans. Güç ZG, Güç H, Bütün O, Alacacıoğlu A, Demirdöver C. Journal of Plastic, Reconstructive & Aesthetic Surgery : JPRAS. 2023;77:244-252. doi:10.1016/j.bjps.2022.11.002.
- Outcome After Surgical Treatment of Dermatofibrosarcoma Protuberans (DFSP): Does It Require Extensive Follow-Up and What Is an Adequate Resection Margin?. Alshaygy I, Mattei JC, Basile G, et al. Annals of Surgical Oncology. 2023;30(5):3106-3113. doi:10.1245/s10434-022-12953-8.
- Management of Dermatofibrosarcoma Protuberans. Badhey AK, Tikhtman R, Tang AL. Current Opinion in Otolaryngology & Head and Neck Surgery. 2021;29(4):278-282. doi:10.1097/MOO.0000000000000721.
- Dermatofibrosarcoma Protuberans. Allen A, Ahn C, Sangüeza OP. Dermatologic Clinics. 2019;37(4):483-488. doi:10.1016/j.det.2019.05.006.