Pediatric and adult primary sarcomas of the kidney: a cross-sectional imaging review

Abstract

There is a wide pathological spectrum of kidney sarcomas that show characteristic histology, ontogeny, and clinical-biological behavior. While leiomyosarcomas commonly arise from the capsule, solitary fibrous tumors and clear cell sarcomas typically show renal sinus and medullary epicenter, respectively. Although distribution and imaging findings of some sarcomas may be characteristic, definitive diagnosis warrants histopathological examination following surgery. Renal sarcomas manifest advanced disease at presentation and portend poor prognosis.

Primitive Neuroectodermal Tumors of the Kidney

“…Th e imaging characteristics of renal PNET are often nonspecifi c and overlap with those of other renal tumors, such as renal cell carcinoma, Wilms tumor, neuroblastoma, lymphoma, and desmoplastic small round cell tumor (11). Renal PNETs appear hypoechoic, isoechoic, and ⁄ or hyperechoic to the adjacent renal parenchyma on ultrasound and show increased vascularity on Doppler imaging.…”

Peripheral neuroectodermal tumour of the kidney (Ewing’s sarcoma): Restaging with 18F-fluorodeoxyglucose (FDG)-PET/CT

“…For the cases reported in the literature, tumour size ranges between 5.5 and 23 cm. 9 In the literature, PNET/EWS has been reported to cause thrombus of the tumour in the renal vein, vena cava inferior, and right heart. 10,11 The clinical findings are uncharacteristic and patients usually complain of pain (85%), palpable masses (60%), and hematuria (37%).…”

“…13 The differential diagnoses include Wilm's tumour, neuroblastoma, renal cell carcinoma (RCC), malignant lymphoma, metastatic renal involvement from sarcoma elsewhere in the body, and renal involvement by a primary retroperitoneal sarcoma. 9,13 The pathological pictures leading to a diagnosis of PNET/EWS are the presence of neurosecretory granules with electron microscopy and the presence of rosettes or pseudorosettes with light microscopy. 8 NSE, chromogranin A, synaptophysin CD56, CD3, CD20, CD99, CD117, WT-1, Fli-1, AE1/AE3, MYF-4, desmin, S-100 and TdT are used in immunohistochemical examination, but the expression of surface antigen CD99 is diagnostic.…”

“…9,13 The MRI and CT can accurately assess local resectability and detect distant metastases. Bone scanning using 99-technetium has been recommended to detect bone metastases.…”

Primary Renal Leiomyosarcoma: A Case Report

“…Leiomyosarcoma account for 50-60% of kidney sarcomas; followed by liposarcomas in 10-15% of cases 1 . They usually occur in the right kidney 2 .…”