!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.1//EN” “http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd”>
|
I. PRESENTATION
A. Subjective. Symptoms from renal cell carcinoma (RCC) can be caused by local tumor growth, paraneoplastic syndromes, or distant metastases. The classic triad of flank pain, gross hematuria, and palpable abdominal mass is present in less than 10% of patients and indicates locally advanced disease. Paraneoplastic syndromes occur in approximately 20% of patients at presentation and up to 40% during the course of their disease. Hypercalcemia, the most common paraneoplastic manifestation of RCC, occurs in approximately 15% of patients and may be due to bone metastases or production of parathyroid hormone-related protein (PTHrP). Nonmetastatic hepatic dysfunction, also known as Stauffer’s syndrome, is characterized by elevated alkaline phosphatase, elevated prothrombin time, and hypoalbuminemia, with some patients also having elevated bilirubin and liver transaminases. Most patients have associated fever, weight loss, neutropenia, and thrombocytopenia. Symptoms improve or resolve in the majority of patients undergoing nephrectomy. Although erythrocytosis occurs in up to 5% of patients owing to increased production of erythropoietin, anemia is a far more common manifestation, usually with parameters of anemia of chronic disease. Hypertension may occur in up to 40% of patients with RCC and is usually caused by either renin secretion by the tumor or secondary to compression of the renal artery and parenchyma. Constitutional symptoms including fever, weight loss, and fatigue occur in approximately one-third of the patients at presentation. The most common sites of metastases are the lungs, bone, and liver. More recent patient series have shown an increased percentage of asymptomatic patients with incidental diagnosis during radiological investigation of unrelated problems.
B. Objective. Hematuria and flank mass are the most common objective findings in RCC. Scrotal varicoceles are usually left-sided or bilateral owing to higher pressure in the left renal vein, and decompress in the supine position. The presence of unilateral right-sided varicoceles or the lack of reduction in the supine position is suspicious for inferior vena cava (IVC) thrombus, which may be caused by RCC.
II. EVALUATION OF A RENAL MASS. Patients with unexplained hematuria, flank pain, or mass suggesting RCC should be evaluated with a radiographic study, preferably computed tomography (CT) scan. Magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA) may be used for further evaluation of the collecting system or IVC involvement. Because of the increased background activity of healthy renal tissue and fluorodeoxyglucose (FDG) excretion in the urine, positron emission tomography (PET) scan has limited value in the RCC diagnosis. With the presumptive diagnosis of RCC by the characteristic radiographic appearance, most patients without metastases undergo resection, which provides both diagnosis and treatment. In patients that are unfit for surgery, renal biopsy of small masses may be performed with minimal risk of tumor spreading, and such patients may be offered cryoablation.
III. PATHOLOGY. RCC is not a single disease but rather a heterogeneous group of cancers originating in the renal tubular epithelium, with distinct morphology, biology, and response to therapy. Clear cell is the most common subtype, representing approximately 75% of the cases. These tumors arise in the proximal tubule and frequently have loss of 3p25, which is the locus of the von Hippel–Lindau (VHL) gene. These tumors have a vascular stroma with frequent development of hemorrhagic areas. Papillary carcinomas represent approximately 15% of RCCs, also arise in the proximal tubule, are more commonly bilateral and multifocal compared with other subtypes, and may be subdivided into type 1 and type 2, which may be associated with mutations in c-met or fumarate hydratase, respectively. Chromophobe tumors represent approximately 5% of the RCC cases, arise in the distal nephron, may be associated with a higher incidence of liver metastases compared with other histologies, and have an overall better prognosis compared with clear cell carcinomas. Collecting duct carcinomas account for approximately 1% of the cases and usually behave aggressively, with metastases at presentation. Renal medullary carcinomas are aggressive tumors associated almost exclusively with sickle cell trait. Renal oncocytomas are benign tumors (Semin Cancer Biol 2013;23:3).
IV. WORKUP AND STAGING. The initial workup for patients with a suspicious renal mass incudes history and physical examination, complete blood count, metabolic panel, urinalysis, and chest imaging. MRI of the abdomen may be performed to rule out IVC involvement. If a central mass is present suggesting urothelial carcinoma, patients should have urine cytology performed. Since most metastases to the bones or brain are symptomatic at presentation, bone scan and brain MRI are performed only when clinically indicated.
The current staging for RCC divides the T stage into T1 (tumor ≤7 cm limited to the kidney; T1a ≤4 cm, T1b >4 to 7 cm), T2 (tumor >7 cm limited to the kidney), T3 (tumor extending into major veins or perinephric tissues), and T4 (tumor invades beyond the Gerota’s fascia including the ipsilateral adrenal gland). N stage is divided into N0 (no regional lymph node metastases) and N1 (metastasis in regional lymph nodes), whereas M stage is divided into M0 or M1 on the basis of the absence or presence of distant metastases. Stages I and II are defined by the presence of T1 and T2, respectively, without lymph node or distant metastases. The presence of T3 or N1 defines stage III, whereas stage IV is defined by T4 or M1.
V. TREATMENT
A. Localized disease (stage I).
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
