Epidemiology:
Rare, <0.1% of all malignant neoplasms, approximately 1% of soft tissue sarcomas
-twice as common in African Americans as in Whites. An uncommon pigmented variant (Bednar tumor) is 7.5 times more common in Blacks.
-20-50 yo, M=F
-no heredity, may be associated with previous sites of trauma
-Chromosome translocation t(17,22) is detected in more than 90% of DFSP tumors.
Diagnosis:
slow growing cutaneous large indurated plaque with red-brown firm irregular nodules
-most common in the trunk > proximal extremities > head and neck (10-16%)
DDx:
-dermatofibroma (superficial benign fibrous histiocytoma) - common, puritic and tender, it is the most common painful skin tumor. F>M (4:1), young adulthood, lower extremities most common
-morphea, atypical fibroxanthoma, SCCa, melanoma
Treatment:
- Surgery is the primary treatment. A wide excision of 2-3 cm or more of the margins beyond clinically identifiable tumor border, down to and including the fascia, is recommended for the treatment of DFSP. Despite this, there is a HIGH recurrence rate of 52% in the head and neck and 16% in the body. Mohs is the treatment of choice.
- Imatinib mesylate is indicated for the treatment of adult patients with unresectable, recurrent, and/or metastatic DFSP.
Prognosis:
Locally aggressive with high recurrence rate. 99.2% 5-year survival
1-4% with metastasis, and almost all have died within 2 years
-most recurrences occur within 3 years of dx
Dermatofibrosarcoma protuberans (DFSP) tumor cells take over the dermis and subcutaneous adipose tissue and then approach the fascia plane. The tumor nodule manifests with high cellularity. Under histopathologic examination, these DFSP tumor cells are spindle shaped. They tend to grow in a storiform pattern in the center portion of the tumor. They may also grow in a diffuse infiltrative pattern at the periphery, forming a honeycomb pattern. Often, no defined border can be recognized between the tumor and normal tissue. (From Medscape)
