Disparate Presentations of Localized Cystic Disease of Kidney: A Review with an Objective of Correct Approach for Accurate Treatment Plan

BACKGROUND: Localized cystic disease of the kidney is a rare, non-familial condition. Its imaging and clinical features are unique and need to be differentiated from autosomal dominant polycystic kidney disease and focal cystic masses such as multicystic nephroma and cystic renal cell carcinoma. It is always restricted to one kidney and is characterized by multiple cysts of varying sizes separated by residual normal renal tissue. MATERIALS AND METHODS: This study reports 12 cases of localized cystic disease of the kidney based on imaging findings and clinical histories. The modalities of choice were ultrasonography followed by contrast-enhanced computed tomography. Eight out of 12 patients were men and the average age of presentation was 46 years. The screening of family members and relatives was done to rule out the differentials. RESULTS: Localized cystic disease of kidney was diagnosed in all the patients and it presented in two different forms. In three patients, multiple cysts involved whole of the kidney, resulting in thinned-out residual renal parenchyma. In the rest nine patients it remained localised to a particular segment of the kidney. No cysts were observed in the contralateral kidney in seven patients, and one or two simple cysts were observed in five. Clinical presentations included only flank pain in six patients, flank pain with palpable abdominal mass in four patients, two patients presented as asymptomatic cases with diagnosis as an incidental finding and one patient with hematuria. Eight patients underwent imaging and two underwent clinical follow-up for a period of two years showing stability of the disease. One patient underwent nephrectomy for suspected renal neoplasm. CONCLUSION: Localized cystic disease of the kidney is a unilateral, rare and stable disease that has two different forms of presentations. Its imaging findings should be clearly understood so as to not classify it as a separate disease and avoid unnecessary surgery. It rarely leads to hypertension or polycythemia, and until then no definitive management is required. It can be followed up using imaging techniques and requires nephrectomy only when the suspicion of malignancy is strong.