Dysgenetic hypoplastic kidney simulating metastatic lung carcinoma

Area of Science:

• Oncology
• Radiology
• Nephrology

Background:

• Lung cancer staging often involves integrated positron emission tomography (PET) and computerized tomography (CT) scans.
• Metabolic activity detected by PET scans can indicate the presence of metastatic disease.
• Patients with a history of kidney disease or transplantation may present unique diagnostic challenges.

Observation:

• A 57-year-old male with a history of absent right kidney and kidney transplant was diagnosed with lung cancer.
• Integrated PET-CT scan for staging revealed abnormal uptake in the lung primary and the right renal fossa.
• The uptake in the right renal fossa was initially interpreted as metastatic disease.

Findings:

• Excisional biopsy of the right renal fossa mass demonstrated a hypoplastic kidney.
• The hypoplastic kidney mimicked metastatic disease on the PET scan.
• The patient ultimately underwent successful left upper lobectomy for lung cancer (pathological stage T2N0M0).

Implications:

• Positive PET scan findings require pathological confirmation via biopsy before excluding patients from potentially curative surgical treatment.
• This case underscores the importance of considering anatomical variations and pre-existing conditions in interpreting imaging studies.
• Accurate staging is crucial for appropriate treatment planning in lung cancer patients, especially those with complex medical histories.