Tehran University of Medical Sciences Journal of Orthopedic and Spine Trauma 2538-2330 5 4 2020 10 31 107 9 Ehsan Hedayat Department of orthopedic Surgery, Dr Shariati Hospital , Tehran University of Medical Sciences, Tehran, Iran. Mohammad Hossein Nabian Department of Orthopedic Surgery, Center of Orthopedic Trans-Disciplinary Applied Research, Shariati Hospital, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran 2020 07 02 2020 10 31 Background: Cystic hygroma (cystic lymphangioma) is a malformation of the lymphatic system. It is rare in adults and trauma may be the cause in some cases. Surgical and non-surgical treatment methods have been described in the management of cystic hygroma. Case Report: A 38-year-old woman, known case of systemic lupus erythematosus (SLE), presented a huge cystic formation in the posterior aspect of her thigh following trauma. We treated the patient using a combination of three treatment methods including surgical excision, intra-cavity bleomycin injection, and post-operative use of compression pants.   Conclusion: Huge post-traumatic cystic hygroma in adults is rare. By the combination of the above three therapeutic regimens, there was no cystic lesion recurrence after eight months. https://jost.tums.ac.ir/index.php/jost/article/view/195 https://jost.tums.ac.ir/index.php/jost/article/download/195/170