Lesson of the Month Perinephric myxoid pseudotumour of fat - first described case in allograft kidney, a mimicker of malignancy

Perinephric soft tissue mass lesions with adipose component are extremely rare and encompass a large differential diagnosis ranging from benign to malignant (1-6). These tumours are often discovered incidentally by radiologic imaging techniques. Clinical management of such lesions is clinically challenging. Additionally, they can be extremely difficult to diagnose on biopsy. The few studies describing the spectrum of these lesions lack specific clinical evaluation guidelines.