CONTEXT: Lymphedema consists of extracellular fluid retention caused by lymphatic obstruction. In chronic forms, fat and fibrous tissue accumulation is observed. Genital lymphedema is a rare condition in developed countries and may have primary or acquired etiology. It generally leads to urinary, sexual and social impairment. Clinical treatment usually has low effectiveness, and surgical resection is frequently indicated. CASE REPORT: We report a case of a male-to-female transgender patient who was referred for treatment of chronic genital lymphedema. She had a history of pelvic radiotherapy to treat anal cancer and of liquid silicone injections to the buttock and thigh regions for esthetic purposes. Radiological examinations showed signs both of tissue infiltration by liquid silicone and of granulomas, lymphadenopathy and lymphedema. Surgical treatment was performed on the area affected, in which lymphedematous tissue was excised from the scrotum while preserving the penis and testicles, with satisfactory results. Histopathological examination showed alterations compatible with tissue infiltration by exogenous material, along with chronic lymphedema. CONCLUSION: Genital lymphedema may be caused by an association of lesions due to liquid silicone injections and radiotherapy in the pelvic region. Cancer treatment decisions for patients who previously underwent liquid silicone injection should take this information into account, since it may represent a risk factor for radiotherapy complications.