DERMATOFIBROSARCOMA PROTUBERANS: AN UNUSUAL CASE OF A MONS PUBIS TUMOUR

Dr Siti Nurliana Osman, Dr Vigneswaran Ramakrishnan, Dr Hamidah Omar

Shah Alam Hospital, Ministry of Health, Malaysia

Objective

The aim for this case report is to highlight the importance of a full assessment of a mons pubis lesion prior to surgery. 

Case Report

A healthy 46-year-old lady presented with a history of a mons pubis swelling for 10 years. It started as a small lesion, however, within the last 6 months, had grown rapidly. She did not have any pain nor any discharge. There were no constitutional symptoms nor family history of cancer.

On examination, there was a protuberant growth over the left mons pubis measuring 5x4 cm with peau d’ orange surface. There was no discharge, not tender, appeared superficial with small nodules felt over the overlying skin which extended to the left inguinal region and down to the left labia majora. Both vulva and vagina were normal.

In view of its chronic history, it was initially thought as a benign growth. However, reassessment done by a senior consultant raised a suspicion of malignancy thus further imaging and opinion from a gynae oncologist was sought.

An ultrasound showed an increased vascularity seen in the superficial pedunculated lesion with feeding vessels seen going into it. 

She was planned for a wide excisional biopsy. The procedure and post-operative recovery were uneventful.

Histology confirmed dermatofibrosarcoma protuberans with margins involved. CD34 immunostaining was positive. Her CT scan showed no distant metastasis. She received adjuvant radiotherapy in view of margins involved, however complicated with grade 3 proctitis. She has been disease-free since and on a 3-monthly surveillance

Discussion

Dermatofibrosarcoma protuberans is a rare soft tissue neoplasm. In our case, the tumour was superficial which initially thought as benign. It is a low grade tumour, albeit, 10% of them may exhibit aggressively. It presents as an indolent growth for years before entering a rapid growth phase, as seen in this patient.

The mainstay of treatment is a wide local excision. Mohs micrographic resection is an alternative surgery however, not readily available and has comparable outcome.

Adjuvant radiotherapy is indicated if the margins are involved or macroscopically unresectable. It rarely metastasises, though if it occurs, it shows a poorer prognosis.

Conclusion

In conclusion, a mons pubis lesion requires a thorough assessment prior to surgery as one might miss a rare tumour which can lead to an incomplete resection.

References

1. Edelweiss M., Malpica A. Dermatofibrosarcoma protuberans of the vulva: a clinicopathologic and immunohistochemical study of 13 cases. Am. J. Surg. Pathol. 2010;34(3):393–400

2. Paradisi A., Abeni D., Rusciani A., Cigna E., Wolter M., Scuderi N. Dermatofibrosarcoma protuberans: wide local excision vs. Mohs micrographic surgery. Cancer Treat. Rev. 2008;34(8):728–736

Acknowledgement

We would like to thank the Director of Health Malaysia for his permission to publish this case report. Our sincere gratitude and appreciation to those who were involved in this study.