Schwannoma of the kidney with magnetic resonance images of non-homogenous renal mass--a case presentation.

Schwannomas are rare tumours that originate from the neural sheath and are usually located in the head and neck, extremities, and posterior mediastinum. Although 3% of schwannomas occur in the retroperitoneum, involvement of visceral organs is extremely uncommon. Schwannomas of the kidney are rare, with only a few reported cases. A 55-year-old woman was referred to our hospital with an abdominal sonography showing a spherical lesion in the upper pole of the left kidney that did not have the characteristics of a cortical cyst. The ultrasound had been recommended from her family doctor, due to a non specific pain in the hypogastrium in the previous 10 days. The final pathologic diagnosis was intrarenal benign schwannoma. Schwannomas are rare renal tumours with usually benign behaviour. Due to nonspecific symptoms and limited radiologic features for the diagnosis and assessment of the benign or malignant character of the tumour, the therapeutic approach is similar to other renal tumours. The definitive diagnosis is achieved with the help of immunohistochemistry.