Table 1.

Histological subtypes of dermatofibrosarcoma protuberans^*

SUBTYPES	HISTOLOGICAL FEATURES	CLINICAL RELEVANCE
“Classic” DFSP	Uniform “storiform” spindle cells with elonaged nuclei, little/no pleomorphism and scanty pale cytoplasm, little mitotic activity	Most common; low rate of metastasis (≤0.5%)
Sclerotic DFSP	Abundant stroma, bundles of collagen in layers, few cells overall, and associated with areas of denser cellularity	Rare type
Giant cell fibroblastoma	Presence of giant multinucleated cells, sinusoidal vessels, myxoid stroma	Observed in children
Bednar tumor	Pigmented variant of DFSP in 5% of all tumors, melanocytes, and deposits of melanin	Seen in African-American individuals
Myxoid DFSP	Nodules of spindle cells with eosinophilic cytoplasm	Rare type
Atrophic DFSP	Atrophy of the mid-dermis compared to tissue adjacent to the tumor, with the subcutaneous tissue closer to the epidermis	Rare type; presents clinically as an atrophic plaque; observed in children
Fibrosarcomatous DFSP	Higher cellularity, increased mitotic rate, marked nuclear pleomorphism, and loss of CD34 in approximately 50% of cases	Highest metastatic potential among DFSPs (≤15%); recurrence rate of approximately 58%; more aggressive DFSP subtype; presence often noted in recurrent tumors, especially with multiple recurrences

^*Histological subtype will modify the clinical appearance of the lesion in some cases