An unusual case of a large cystic swelling in thigh: cystic lymphangioma in an adult

Cystic lymphangioma is a rare congenital malformation found almost exclusively in the pediatric age group. Approximately 100 adult cases have been reported in the literature, mostly in the head and neck region. Trauma has been suggested as a possible etiology in the development of such lesions in adults. We report a case of cystic lymphangioma in the lower limb of an adult, which is so far the largest one reported and may support this theory. The patient developed the lesion after sustaining trauma to the left thigh in a road traffic accident. It subsequently progressed to a massive size over 20 years. The histopathology of the excised lesion showed evidence of an organized hematoma supporting the theory of trauma as a likely etiology in the development of these lesions in adults. A relevant review of the literature is also presented.