Reduction of polycystic kidney and liver volumes in a patient with tolvaptan-resistant autosomal dominant polycystic kidney disease and acromegaly during lanreotide therapy.

A 35-year-old female was diagnosed with autosomal dominant polycystic kidney disease (ADPKD) in 2002 and referred to the Nephrology department of our hospital for follow-up and management. Treatment with tolvaptan was started in 2016, which failed to reduce her total kidney volume (TKV) and slow the decline in kidney function. In 2018, she experienced bitemporal hemianopia. Examination revealed enlarged fingers, characteristic facial features, and elevated serum insulin-like growth factor 1 (IGF-1) and growth hormone (GH) levels. A pituitary tumor was identified through the brain, and she was subsequently diagnosed with acromegaly. Lanreotide treatment was initiated, effectively reducing IGF-1 and GH serum levels and TKV within six months. After transsphenoidal surgery, lanreotide was discontinued. However, her oral glucose tolerance test after surgery did not show remission (GH nadir > 0.4 ng/mL), and serum GH levels gradually increased. Furthermore, TKV increased and kidney function decreased rapidly. Lanreotide treatment was restarted, resulting in further TKV reduction, suppression of liver volume enlargement and slowing kidney function decline. Compared to tolvaptan, the evidence for the effectiveness of somatostatin analogs in reducing TKV in ADPKD is not sufficiently established. Our case demonstrates that lanreotide effectively suppressed the progression of TKV, liver volume and kidney dysfunction with correlation to IGF-1 or GH in a patient with ADPKD. Our experience indicates that elevated levels of IGF-1 or GH may contribute to increased kidney and liver volume. Herein, we report the first case of tolvaptan-resistant ADPKD with concomitant acromegaly successfully managed with lanreotide.