[907] Percutaneous Core Needle Biopsy; a Helpful Tool in the Diagnosis of Hereditary Kidney Tumors

J Vicens, P Pinto, WM Linehan, MJ Merino. National Cancer Institute, Bethesda, MD

Background: Accurate preoperative diagnosis of renal masses is crucial for clinical evaluation and treatment of patients. Percutaneous imaging-guided biopsy of renal masses is becoming an important tool in the diagnosis and treatment of renal cancer. In this study we report our experience with imaging guided percutaneous core biopsies (PCB) performed in patients with known hereditary kidney tumors.
Design: We present 41 PCB specimens obtained from 40 patients presenting with renal tumors. Family clinical history included VHL, HPRCC type I, BHD syndrome, Succinate dehydrogenase deficiency and Tuberous sclerosis. Material was obtained for special studies, IHC and EM.
Results: There were 18 female and 22 male patients, ranging in age from 6-87 years, (mean 51) Definite diagnoses was performed on PCB in 40 (98%) cases. Thirty tumors were malignant, 1 had neuroendocrine features, 4 had oncocytic characteristics and 5 were benign. Only 1 sample was insufficient for diagnosis. Malignant lesions included renal cell carcinoma (RCC) clear cell type (13 cases), papillary RCC or with papillary features (9 cases), RCC with eosinophilic and/or clear cell features (2 cases), chromophobe RCC (2 cases), medullary carcinoma (1 case), RCC with features of clear cell sarcoma (1 case) and poorly differentiated carcinoma (2 cases). Subtypes of tumors with papillary features included 8 cases suggestive of papillary type I and 1 case HLRCC. Benign cases comprised 4 oncocytomas and 1 angiomyolipoma. The remaining tumors included 4 oncocytic and 1 neuroendocrine neoplasms. Tumors with eosinophilic features were challenging when differentiating between oncocytomas, chromophobe and hybrid tumors. Resected specimens confirmed the preoperative pathologic diagnosis in 11 of 13 (85%). A clear cell RCC by PCB was considered as a possible Pecoma but could not be confirmed in the specimen. One PCB diagnosed as oncocytic neoplasm was a chromophobe RCC in the resected specimen. The neuroendocrine neoplasm was a neuroendocrine carcinoma. The patient with an insufficient core biopsy was diagnosed with malignant mesothelioma.
Conclusions: Percutaneous imaging guided core biopsies are an excellent tool to diagnose Hereditary renal tumors. Definite diagnosis was performed in 98% of tumors. However caution is recommended in this group of patients when tumors with eosinophilic and papillary features are encountered, since hybrid and papillary features may lead to a wrong interpretation.
Category: Genitourinary (including renal tumors)

Tuesday, March 10, 2009 9:30 AM

Poster Session III # 84, Tuesday Morning