Localised cystic renal disease (LCRD) (or localised cystic kidney disease) is an uncommon, non-familial, non-progressive disease characterised by clusters of cysts within normal renal parenchyma. It can be confused with unilateral autosomal dominant polycystic kidney disease (ADPKD), multilocular cystic nephroma (MLCN), or cystic neoplasm.
Variable age of presentation reported from 16 to 83 years. Median age is 50 years old with a proposed male predilection 1-3.
Localised cystic renal disease can present as an incidental finding due to imaging for other reasons. Haematuria, pain and abdominal mass have also been described.
Reported cases do not encompass a large number. When pathological samples have been obtained the following characteristics were displayed:
- segmental involvement of the kidney with conglomerate, non-encapsulated cysts of varied sizes,lined with flattened epithelium; cysts appear between regions of normal or atrophic parenchyma
- smooth walled cysts with either thin yellow fluid or haemorrhagic contents
- papillary formation and calcification are not a feature
- same gross histological appearance as autosomal dominant polycystic kidney disease (ADPKD)
Renal cysts in LRCD can involve segments of the kidney or the entire kidney but are always unilateral. The key feature is that the cysts are separated by normal or atrophic renal parenchyma.
Ultrasound shows multiple small simple cysts in a segmental or unilateral distribution with normal renal parenchyma in non affected segments and intervening between cysts. Contralateral kidney is unaffected 2. No Doppler signal in the cysts 3.
CT findings are characteristic:
- segmental/unilateral renal involvement
- normal atrophic parenchyma separating cysts
- normal contralateral kidney
- unencapsulated mass
- can have scattered calcification in cyst walls
- haemorrhagic high attenuation cysts usually resulting from trauma
- T2: multiple cysts of high T2W signal intensity, normal intervening parenchyma
- T1 C+ (Gd): no enhancing nodularity
- MRA: increased intensity of the main renal artery and splaying of the intrarenal vessels around cystic structures
Treatment and prognosis
Good prognosis with no potential for malignant transformation. Partial and total nephrectomy when there is a suspicion of malignancy or where the LRCD is not recognised 1.
The main differential is unilateral autosomal dominant polycystic kidney disease (ADPKD). Others include:
- 1. Slywotzky CM, Bosniak MA. Localized cystic disease of the kidney. AJR Am J Roentgenol. 2001;176 (4): 843-9. doi:10.2214/ajr.176.4.1760843 - Pubmed citation
- 2. Neyaz Z, Kumar S, Lal H et-al. Localized cystic disease of the kidney: a rare entity. J Radiol Case Rep. 2012;6 (7): 29-35. doi:10.3941/jrcr.v6i7.1026 - Free text at pubmed - Pubmed citation
- 3. Solak A, Gür MS, Genç B et-al. Localized cystic disease of the kidney: a rare cause of hypertension in a young adult. J Clin Imaging Sci. 2013;3 (1): 33. doi:10.4103/2156-7514.116191 - Free text at pubmed - Pubmed citation
- 4. Ding Y, Chen L, Deng FM et-al. Localized cystic disease of the kidney: distinction from cystic neoplasms and hereditary polycystic diseases. Am. J. Surg. Pathol. 2013;37 (4): 506-13. doi:10.1097/PAS.0b013e318271eff9 - Pubmed citation