Multilocular cystic renal neoplasm-low malignant potential (MCRN-LMP) - review

Abstract

Multilocular Cystic Renal Neoplasm of Low Malignant Potential (MCRN-LMP), previously known as multilocular cystic renal cell carcinoma as a rare variant of cystic kidney. It is composed of multiple cysts separated by thin septa covered with clear cells with no expansile growth. The termMCRN-LMPshould be used exclusively to identify a cystic kidney lesion with a small clusters of neoplastic clear cells in the cyst walls. Clinically these cases may present with flank pain or the majority of these tumors are incidentally found on radioimaging. Grossly, the tumor is well demarcated and consists of multiple various-sized cysts. The fibrous septa are generally thin and there is no discernible expansile nodule. The WHO/ISUP nuclear grade is generally low and usually corresponds to grade 1 or 2. In the World Health Organisation (WHO) 2016 classification of kidney tumors recognizes MCRN-LMP as a rare variant of cystic kidney. MCRN-LMP generally exhibits a low stage of TNM classification. These tumors have a favorable clinical course. The clinical course of these lesions suggests that patients may benefit from nephron-sparing surgery. The aim of this review is to bring attention, that MCRN-LPM is a low aggressive neoplasm with no recurrence and no metastatic potential. The updated diagnostic modalities and conservative line of management may be applicable for this rare entity for the better care of patients.