Pararenal sclerosing PEComa.

Small renal or pararenal masses and retroperitoneum lesions are extremely difficult to diagnose. Imaging technology is a precious diagnostic tool; however, it places physicians in a difficult position since many lesions are not precisely diagnosed. Clinical and radiological findings can guide suspicion towards the diagnosis; however, in our current practice most diagnoses are based on histological findings. We aim to present a pararenal sclerosing perivascular epithelioid cell tumour (PEComa), a rare entity, whose diagnosis is only possible through invasive approaches and histological analysis. This rare lesion not only is difficult to diagnose but also has an uncertain behaviour, which is of major importance concerning its follow-up and prognosis. This case report is an attempt to add more data that will help establish criteria for diagnosis and follow-up of this rare disease.