Kidney lesion with similar genetic and cytologic characteristics to clear cell renal cell carcinoma (CCRCC), but is entirely cystic and lacks solid growth. This tumor has different prognostic features when compared to conventional CCRCC as it is always indolent, without recurrence or progression.

Unilateral solitary lesion, asymptomatic and frequently detected incidentally.

The tumors contain fluid-filled cysts separated by thin fibrous septae lined by renal epithelial cells. These single layers of cells have clear cytoplasm similar to that seen in CCRCC and small nuclei typically no more than ~10microns in diameter. Small (minute, microscopic) invasive tumor nests may be seen in septae stroma. Solid nodular growth, necrosis, and sarcomatoid differentiation are not seen in this tumor type. ¹

Favorable prognosis, do not recur or metastasize

Deletion of chromosome 3p/monosomy 3  by FISH analysis has been demonstrated, with comparable frequency to clear cell renal carcinoma.^1,2

VHL mutations have also been detected ^3,4, but not KRAS mutations.⁵

Six novel genetic alterations GIGYF2, FGFR3, SETD2, BCR, KMT2C and TSC2 could be potential candidate genes for differentiating  multilocular cystic renal neoplasm of low malignant potential from clear cell renal cell carcinoma with cystic change.⁶