Clear cell tubulopapillary renal cell carcinoma

Abstract

BACKGROUND: Clear Cell Tubulopapillary Renal Cell Carcinoma (CCTP RCC) is a recently described biphasic neoplasm, composed of an epithelial component, CK 7 positive and CD10 negative, and an angioleiomyomatous stroma. We present a case of CCTP-RCC and literature review.
CASE REPORT: A 66 year-old asymptomatic female presented with a solid mass in the lower pole of the right kidney. Underwent partial right nephrectomy. Macroscopic examination of the specimen revealed a solid lesion, 4.5 x 3.5 cm, encapsulated, yellow and fibrous. Light microscopy revealed a well-defined biphasic tumor showing tubulo-acinar and papillary structures, composed of clear epithelial cells with moderate nuclear atypia (Fuhrman 3), without areas of necrosis or signs of invasion. For immunohistochemistry, these epithelial cells were positive for CK 7 and negative for CD 10, with focal stromal positivity for desmin, immuno-morphologically compatible to CCTP-RCC.
DISCUSSION: Recently, a case series of CCTP-RCC has been published. This neoplasm is characterized by clear cells in cystic, tubuloacinar or papillary arrangement, with no signs of aggression, and typical immunophenotype (CK 7 positive and CD10 negative), as seen in this case. This is a new entity with good prognosis, without gender preference, affecting mainly people over 60 years. Molecular studies may contribute, however the diagnosis is based on typical immuno-morphological finds. Its correct recognition is essential for clinical management and prognosis. Nevertheless, more reports and studies are still needed in order to better clarify this new entity and its biological behavior.