Endoluminal Sonographic Evaluation of Ureteral and Renal Pelvic Neoplasms

1954

RENAL TUMORS, RETROPERITONEUM, URETER, AND URINARY DIVERSION AND RECONSTRUCTION

of proliferation potential in differentiating hemangioblastoma from RCC metastatic to the central nervous system using a MIB-1 (Ki-67) labling index and assessment of expression of the RNA component of telomerase. Immunohistochemical analysis for epithelial membrane antigen ( E m ) and MIB-1 was performed on paraffin-embedded sections of 27 hemangioblastomas and 5 RCC metastatic to the central nemous system. All but one hemangioblastoma demonstrated low or negative MJB-1 immunoreactivity, while 4 of 5 RCC metastases had moderate or high labeling indices. Telomerase RNA expression was assessed in 10 hemangioblastomas and in all 5 metastatic RCC by in situ hybridization. All 10 hemangioblastomas demonstrated a lack of expression of telomerase RNA, while all 5 metastatic RCCs showed moderate to strong expression. Our results suggest that the MIB-1 labeling index is useful in differentiating hemangioblastoma from metastatic RCC and assessment of telomerase expression can also provide novel information on the difference in growth potential of these tumors.

Editorial Comment: Hemangioblastomas are low grade neoplasms of the cerebellum and spinal cord and frequently occur in the setting of the von Hippel-Lindau syndrome. Renal cell carcinoma is also common in that syndrome. At times it can be difficult to distinguish hemangioblastoma from metastatic renal cell carcinoma in the central nervous system. Epithelial membrane antigen has been used to help distinguish these 2 neoplasms. The authors describe the use of Ki-67, a nuclear membrane associated protein that is expressed in all phases of cell cycle except GO. Immunohistochemical analysis of Ki-67 (MIB-1) can be performed in paraffin sections and there was a marked differencebetween metastatic renal cell carcinoma, which had a high proliferation index, and hemangioblastomas, which had a low proliferation index. In addition, the expression of the enzyme telomerase is associated with immortality of cancer cells. Telomerase was expressed in all of the metastatic renal cell carcinomas and was not seen in the hemangioblastomas. Molecular markers help diagnose tumors when histopathological differentiation is difficult. Fray F. Marshall, M.D. Endoluminal Sonographic Evaluation of Ureteral and Renal Pelvic Neoplasms J.-B. Lru, D. H. BAGLEY, M. J. CONLIN,D. A. MERTON,A. A. ALEXANDER AND B. B. GOLDBERG, Division of Diagnostic Ultrasound, Departments of Radiology and Urology, Thomas Jefferson University Hospital, Jefferson Medical College, Philadelphia, Pennsylvania, and Division of Urology and Renal Transplantation, Oregon Health Sciences University, Portland, Oregon J. Ultrasound Med., 1 6 515-521, 1997 Abstract Printed in J. Urol., 159 318, 1997

Editorial Comment: These authors describe 38 patients who had endoluminal ultrasound evaluation of upper tract neoplasms. This examination was performed with a 12.5 or 20 MHz. transducer housed in only a 6.2F catheter. Invasion was demonstrated ultrasonographically in 5 patients and was confirmed pathologically in 3. There were 2 false-positiveswith diffuse wall thickening and focal mucosal edema. However, in most patients the ultrasonographic evaluation was accurate. These higher megahertz transducers provide increased tissue resolution, although less tissue penetrance. In some endoscopic or laparoscopic procedures ultrasound can provide the operator with vision beyond the immediate surface on which he/she is working. Fray F. Marshall, M.D. Epithelioid Angiomyolipoma of the Kidney. A Report of Five Cases With a Prominent and Diagnostically Confusing Epithelioid Smooth Muscle Component J. N. EBLE,M. B. AMINAND R. H. YOUNG,Indiana University School of Medicine and Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana, Henry Ford Hospital, Detroit, Michigan, and Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts Amer. J. Surg. Path., 21: 1123-1130, 1997 We report five angiomyolipomas with a prominent component of epithelioid smooth muscle cells that occurred in patients from 20 to 48 (mean, 36) years of age. The tumors often posed problems in diagnosis, particularly with regard to distinction from renal cell carcinoma. Two patients had tuberous sclerosis. Two patients with more than 5 years’ follow-up are alive and well. The epithelioid smooth muscle cells typically formed sheets that in two tumors were traversed by hyaline cords. The epithelioid cells ranged from medium sized and polygonal with slightly pleomorphic nuclei and eosinophilic cytoplasm to giant cells with prominent nucleoli. Hemorrhage, necrosis, and clusters of foamy macrophages were present in three tumors. Mitotic figures were easy to find in two of the tumors, but they were absent in the others. Obvious elements of typical angiomyolipoma were present in two tumors. The others contained only scattered, thick-walled blood vessels or a few fat cells suggestive of typical angiomyolipoma. None of the tumors was positive for low- or high-molecular-weight cytokeratins or epithelial membrane antigen. Actin was detected in the epithelioid areas in four tumors. Melanoma-associated antigens related to the ~ 1 0 0 - c gene l product, HMB-45 and HMB-50, were present in all the tumors. Another melanoma-associated antigen, CD63