Deep Tissue Invasion of Dermatofibrosarcoma Protuberance

ABSTRACT

PURPOSE: Dermatofibrosarcoma protuberans(DFSP) is a moderate-degree malignant tumor of soft tissue from dermis to fat layer with high recurrences(11% to 73%) due to its local infiltrative characteristic. Many debates and controversies in deciding accurate surgical margin were presented before, but references about depth of invasion and appropriate surgical excision level were not properly made out. Therefore, we tried to identify the degree of tissue invasion of DFSP. METHODS: Twenty patients, including 8 patients with recurrent lesions, over last 10 years were reviewed retrospectively. Different surgical margins were applied according to the location and based on histopathologic result, we have defined as a 'deep tissue invasion' if there were infiltration of tumor cell into fascia or underlying muscle layer was present. All invaded tissue including dermis, fat, fascia and muscle were excised until no tumor cell was found during intraoperative frozen section biopsy. And comparative analysis of deep tissue invasion according to age, primary site, duration of disease and recurrence was done. RESULTS: Thirteen patients(65%) showed deep tissue invasion and incidence was found to be increasing with age (over 30 years old). All patients with DFSP on head and neck region revealed deep tissue invasion followed by trunk(54%) and lower extremities(50%). There was no relationship between duration of disease and deep tissue invasion. CONCLUSION: It is clear that many cases of DFSP had a deep tissue invasion. And high prevalence of deep tissue invasion with age, primary site was intimately associated. So, underlying deep tissue must be completely examined and excised sufficiently throughout the operation for clear resection of DFSP with no recurrences, especially when the age is over 30s and on head and neck region.