Explosive growth of a renal tumor during active surveillance

Area of Science:

• Nephrology
• Oncology
• Geriatric Medicine

Background:

• Small renal masses (≤ 4 cm) incidence is rising.
• Partial nephrectomy is standard, but active surveillance is gaining traction for select patients.
• Elderly patients and those with comorbidities are often candidates for active surveillance due to slow growth and low metastasis risk.

Observation:

• An 86-year-old female patient was under active surveillance for a 1.4 cm renal mass.
• The lesion demonstrated initial slow growth (0.5 cm/year over 3 years).
• Subsequently, the mass exhibited rapid enlargement to 7 cm with an inferior vena cava (IVC) thrombus within 13 months.

Findings:

• This case illustrates an unusual presentation of rapid renal mass growth.
• The development of an IVC thrombus signifies advanced disease progression.
• Active surveillance may not be suitable for all small renal masses, irrespective of initial growth rate.

Implications:

• Careful monitoring and consideration of alternative treatments are crucial for patients on active surveillance.
• This case underscores the importance of recognizing potential for aggressive tumor behavior.
• Further research is needed to identify predictive markers for rapid growth in small renal masses.