Management of pleomorphic dermal sarcoma.

Background: Pleomorphic dermal sarcoma (PDS) is a rare, poorly defined skin neoplasm with features similar to atypical fibroxanthoma, but with adverse histopathological characteristics indicating metastatic potential such as tumour necrosis, invasion beyond superficial subcutis or vascular and/or perineural infiltration. Optimal treatment for PDS is uncertain and reported outcomes vary due to the rarity of this diagnosis and uncertainty over histopathological categorization. The aim of this study was to review the clinical and histopathological features of PDS in a single Australian centre.

Methods: A retrospective review of all patients managed at the Peter MacCallum Cancer Centre with PDS between 2003 and 2017 was performed by a search of electronic records and histories reviewed.

Results: A total of 27 patients were identified, mostly elderly males (85.2%, mean age 79.8 years). Lesions were seen most commonly on the head and neck region (96.3%), predominantly on the scalp (63%). Mean tumour radial surgical excision margin was 12.8 mm. Eighteen patients (66.7%) underwent radiotherapy; 13 adjuvant, three neoadjuvant and two with palliative intent. After median follow-up of 46.4 months, two patients had recurrence (7.4%); both had inadequate deep margins at first excision. There were three all-cause deaths in the cohort. There was one disease-specific mortality with metastatic PDS disease at the time of initial presentation.

Conclusion: PDS is a rare cutaneous malignancy most commonly found in the head and neck region in elderly men, which is best managed with adequate surgical excision. The role of radiotherapy is undefined and an area for future investigation.