[A rare case of renal ectopic thyroid tissue].

We present a rare case of ectopic thyroid tissue found during robotic nephrectomy of a kidney with a suspected malignant tumour. Such cases of ectopic thyroid tissue are extremely rare in the literature. If ectopic thyroid tissue occurs, it is usually found in the neck region or in the upper mediastinum. Clinical symptoms depend on size, localisation and hormonal function of the ectopic tissue. Surgical resection remains the treatment of choice; in individual cases, conservative treatment can be an option. This case report aims to emphasise that renal tumours of unknown origin might be paraneoplastic or ectopic tissue of other organs.