Symptoms of Kidney Cancer and Appropriate Diagnostic Tools

Abstract

Currently, more than 50 (60)% of renal cell carcinomas (RCCs) are detected incidentally on abdominal ultrasound (US) or computed tomography (CT)/ magnetic resonance imaging (MRI). These tumours are usually smaller and of lower stage. Many patients with renal masses (RMs) remain asymptomatic until the late stages of the disease. RCC can become very large without any symptoms, due to the retroperitoneal position of the kidney. It has been reported that the prevalence of the classic triad of flank pain, gross haematuria, and a palpable abdominal mass in some parts of the world is lower than previously observed (now 6–10%) and correlates with advanced disease and subtypes associated with poor prognosis. Paraneoplastic syndromes are found in approximately 20-30% of patients with symptomatic RCCs (anaemia, hypercalcemia, production of adrenocorticotrophic hormone, polycytemia, hepatic dysfunction, amyloidosis, fever and weight loss). A few patients present with symptoms caused by metastatic RCC (mRCC), such as bone pain, pathological fractures, deterioration of performance status (PS) including fatigue, anorexia, weight loss, pulmonary symptoms (persistent cough), neurological symptoms (result from intracranial and spinal column metastases). Despite the advances in diagnosis, especially improved imaging techniques, about 20–30% of all patients are diagnosed with metastatic disease (symptomatic or asymptomatic metastases). Diagnostic tools as a history, physical examination and laboratory have limited information, mostly in advanced RCC only. Crucial role plays imaging: US is crucial mainly for primary diagnosis, but not sufficient for staging and planning of surgery. Contrast-enhanced multiphase abdominal CT (and/or MRI) are the most appropriate imaging modalities for renal tumour diagnosis/ characterisation and staging. CT features cannot reliably distinguish even oncocytoma and fat-free angiomyolipoma from malignant renal neoplasms. Chest CT is recommended for staging assessment of the lungs and mediastinum and it is more accurate than chest X-ray. MRI: In most clinical aspects, MRI is very similar to CT. Main advantages of MRI are no risk of allergy to iodine contrast fluid and no exposure to radiation (important mainly in pregnancy). MRI may provide additional information to CT on venous involvement if the extent of an inferior vena cava (IVC) tumour thrombus is poorly defined on CT and probably in cystic lesions, but this topic is under investigation. PET CT (MRI): For routine investigation, PET CT is not currently recommended. Interventional imaging techniques (digital subtraction angiography of the renal artery and inferior cavography) were replaced with non-invasive methods (CT, MRI). Angiography is indicated only in therapeutic procedures e.g. embolization of angiomyolipoma and solving of complication following kidney resection (bleeding, arteriovenous fistula). Bone scintigraphy. A bone scan is not routinely recommended, in only special cases, e.g. pathological fractures etc. It can be replaced with FDG PET CT. Chest X-ray. A routine chest X-ray should be done as a minimum in staging and in follow-up. As mentioned above, chest CT is more accurate. Biopsy of primary kidney tumour is indicated in following indications: Small renal masses – before active surveillance (if potential clinical benefit), before ablative treatments and in metastatic RCC to select the most suitable form of medical and surgical treatment strategy. Performing of biopsy is following: Percutaneous, under ultrasound or CT guidance, under local anaesthesia, with core needle about 18G core and with coaxial technique (allowing multiple biopsies – at least two, to avoid tumour seeding).