The exceptional case of a large extra-uterine, so-called parasitic leiomyoma in a post-menopausal woman with Hashimoto's thyroiditis.

A large tumour mass was detected in a 65-year-old patient during a routine gynaecological examination. This patient had been treated for over 10 years with levothyroxine for Hashimoto's thyroiditis and was also given transdermal oestrogen replacement therapy. Before the operation, detailed imaging by CT scan and MRI was performed. A tumour weighing 1.056 grams and measuring 23x12x7 cm was successfully removed through laparotomy. Histopathology revealed the diagnosis of an extra-uterine, so-called parasitic leiomyoma. Post-surgery recovery was uneventful, but Tibolone treatment was indicated due to disturbing menopausal complaints.