Journal of Clinical & Experimental Pathology
Open Access

Abstract

Collision tumor is a phenomenon in which two histologically different tumors exist as distinct lesions within same organ. Renal tumors represent 3% of adult malignancies and 2% of childhood malignancies but their synchronous occurrence is very rare. We present a case of synchronous tumors of kidney comprising clear cell renal cell carcinoma (CCRCC) and chromophobe renal cell carcinoma (CRCC). Grossly, two separate tumor nodules were identified with unremarkable intervening area. Microscopic examination from both tumor nodules revealed two different epithelial malignancies. Sections from larger nodules revealed nests of cells with distinct cell borders, hyperchromatic nuclei, perinuclear halos and eosinophilic granular cytoplasm while sections from smaller nodule revealed sheets and nests of cell with hyperchromatic nuclei, prominent nucleoli and clear to eosinophilic cytoplasm. Sections from intervening area showed renal parenchyma without any tumor infiltration. Larger tumor was positive for CK7 and CD117 immunohistochemical (IHC) stains while negative for CD10 IHC stain confirming the diagnosis of CRCC. However smaller tumor was positive for CD-10 IHC stain and negative for CK7 IHC stain confirming the diagnosis of CCRCC. Prognosis in such cases is determined by the more aggressive of the two tumors as in our case CCRCC is more aggressive with a 5 year survival rate of 50-60% as compared to CRCC with a 5 year survival rate of 80-90%.

Biography

Anila Chughtai has completed her Bachelor of Medicine & Bachelor of Surgery degrees (MBBS) from Services Institute of Medical Sciences, Lahore. Currently, she is working as a second year Post-graduate trainee at Chughtai lab Lahore.