Case Presentation: An 84-year-old male with a past medical history of chronic kidney disease stage III and hypertension presented to our hospital with chief complaints of blurred vision and musculoskeletal pain after an unwitnessed fall. The patient also described worsening abdominal discomfort over the past year associated with an increase in pant size, anorexia, asthenia, constipation, and unintentional weight loss of 6 pounds within the last week.Upon admission, vital signs included a temperature of 99.3o F, heart rate of 99 bpm, blood pressure of 152/85 mmHg, and BMI of 35. Physical examination demonstrated a distended, non-tender abdomen with a large, palpable mass and hypoactive bowel sounds. Pertinent laboratory findings included a BUN of 17 mg/dL (normal 7-20 mg/dL), creatinine of 1.43 mg/dL (normal 0.55-1.30 mg/dL), and GFR of 50. A CT of the abdomen and pelvis demonstrated a 5.5 cm simple cyst on the right kidney and a large, lobulated cystic fluid collection – later identified as the left kidney – measuring over 30 cm x 30 cm and displacing the spleen and bowel. Given initial concern for malignancy, oncology recommended biopsy or nephrectomy, which the patient declined. Urology was consulted and recommended placement of a nephrostomy tube for drainage, upon which 15 mL of dark fluid – representing degraded RBCs – was obtained, followed by 10.5 L of serosanguinous fluid. Cytology and culture of the fluid were unrevealing for malignancy. After drainage of the fluid, the patient showed immediate clinical improvement, reporting increased mobility, visibly decreased abdominal girth, and decreased abdominal and back pain. A follow-up abdominal CT demonstrated a collapsed left renal cyst and a 4.5 cm x 2 cm mass within the superior aspect of the cyst, which was concerning for malignancy. The patient chose to forgo any further surgical interventions and was discharged.
Discussion: Giant hydronephrosis is a rare condition that can be caused by congenital stenosis of the ureteropelvic junction, urolithiasis, and urothelial carcinomas, all of which can cause abdominal organ compression, apparent ascites, and pain. Ultrasounds and CT scans are useful imaging modalities to identify hydronephrosis and demonstrate the extent of organ displacement. Due to the potential kidney dysplasia that can result from long-standing hydronephrosis, simple nephrectomy is the current standard of care. However, percutaneous drainage is a minimally invasive option that may be more suitable in patients who are high-risk candidates for surgical intervention. In patients with rapidly enlarging abdominal masses, early consideration of hydronephrosis and treatment with percutaneous drainage can provide immediate symptomatic relief.
Conclusions: Giant hydronephrosis is a rare condition variably defined by the accumulation of more than 1 L of fluid within the urinary collecting system. Rapid kidney expansion can mimic a progressive malignancy with ill-defined clinical features, thus representing a diagnostic challenge
