ALK and non-small cell lung carcinoma: Patients with ALK-positive NSCLC tend to be relatively young (median age ∽50 years).23 The prevalence of simple cysts observed in this population (22%) is comparable to the rate in the general population in this age group.10 However, 5% of patients had preexisting complex renal cysts, suggesting that there may be a considerably higher prevalence of complex renal cysts in patients with ALK-positive NSCLC than in the general population.