| Additional Info: |
Primary leiomyosarcomas of the kidney are rare, however they are the most common renal sarcoma (WHO). They may arise from smooth muscle elements in the capsule, parenchyma, or renal vein. Other than location, they are histologically similar to their extra-renal counterparts. In more differentiated lesions growth can range from a fasicular to a plexiform, to a haphazard arrangement of characteristic spindle cells with elongated and blunt ended nuclei. Higher grade lesions demonstrate more cytologic atypia and nuclear pleomorphism, so much so that just like their extra renal counterparts, a battery of immunostains needs to be employed for their proper identification. |