A Case of Bednar Tumour in the Sacral Region- A Rare Pigmented Variant of Dermatofibrosarcoma Protuberans

Abstract

Dermatofibrosarcoma Protuberans (DFSP) is a relatively rare soft tissue neoplasm of intermediate malignancy. Metastasis of this tumour seldom occurs. The DFSP is a locally aggressive tumour with a high recurrence rate. The DFSP accounts for less than 0.1% of all malignant neoplasms and approximately 1% of all soft tissue sarcomas. Bednar tumour is an uncommon variant of dermatofibrosarcoma protuberans. Also known as pigmented dermatofibrosarcoma protuberans, this tumour is a rare, aggressive, cutaneous tumour that constitutes 1-5% of all DFSPs of intermediate grade. These tumours can be easily mistaken for fibrosarcoma and melanoma. It is seen in adults with a predisposition to affect the shoulder region, and trunk. Authors hereby report a case of 50- years-old female presented with complaints of recurrent swelling in the lower back for a duration of 4 months. Pain aggravated on lying in the supine position, swelling was painless otherwise. Patient also had complaints of itching over the swelling with occasional blood stained discharge on self-inflicted trauma. Magnetic Resonance Imaging (MRI) scan and histopathological examination of excised tumour confirmed the diagnosis of bednar tumour. She underwent wide local excision with split skin grafting and was on follow-up for the last two years with no evidence of recurrence. Hence, adequate clearance and thorough and regular follow-up is essential to prevent recurrence.