Paraneoplastic Syndrome and Systemic Manifestations

Renal cell carcinoma is associated with several paraneoplastic manifestations. A nephrogenic liver dysfunction syndrome without jaundice
(Stauffer’s syndrome) or cholestatic jaundice develops in some patients. Some renal cell carcinomas produce hormones that have their own manifestations. These include renin (hypertension), parathormone (hypercalcemia), erythropoietin (erythrocytosis), gonadotropin (gynecomastia), and adrenocorticotrophic hormone (Cushing’s syndrome).
Hyperglycemia is rare. Hypercalcemia occurs in a number of clinical settings, including such malignancies as lung, breast, ovary, squamous cell, and renal, and some hematologic cancers. Hypercalcemia is rare with other genitourinary malignancies.
Some patients with proven renal cell carcinoma and without an obvious cause of serum alkaline phosphatase elevation, such as metastases or other liver or bone diseases or pregnancy, have an elevated phosphatase level, probably due to a paraneoplastic syndrome. In some patients alkaline phosphatase normalizes after nephrectomy, and metastases develop later
without phosphatase elevation.
Etiology
Several syndromes are associated with familial renal cell carcinomas, with the best known being von Hippel-Lindau disease. Renal cell carcinomas in this disease tend to be multicentric and bilateral. Hereditary papillary renal cell carcinoma is probably in a distinct class of inherited malignancies. Germline missense mutations, allelic losses and duplications of certain chromosomes, and mutation of the VHL gene occur in some renal cell carcinomas. Involved
individuals appear to exhibit an autosomaldominant transmission with reduced penetrance.
A number of these hereditary renal cell cancers are detected incidentally in asymptomatic individuals. Currently a patient presenting with bilateral, multiple, or an early onset of renal cancer should be investigated for von Hippel-Lindau disease and possibly other syndromes. Birt-Hogg-Dubé syndrome, probably familiar only to dermatologists, appears to be associated with familial renal tumors, including oncocytomas and papillary renal cell carcinomas.
Patients in chronic renal failure undergoing dialysis who then develop acquired cystic kidney disease are at increased risk of developing renal cell carcinomas. These cancers tend to be hypovascular and difficult to detect early in their course. Exposure to certain chemicals increases the risk of developing renal cell carcinoma. Thus long-term exposure to trichloroethylene, an industrial solvent, leads to an increased incidence of these tumors. Patients exposed to high and cumulative doses of this solvent have mutations in the VHL gene. An association exists between the number of mutations and the severity of exposure to this solvent; the mutations are often multiple and show a loss of heterozygosity.
Radiation therapy–induced renal cell carcinoma is rare. In the few reported patients, radiotherapy occurred several decades earlier. With the increased survival seen after therapy for childhood neuroblastomas, these patients appear to be at increased risk for subsequent renal cell carcinoma.
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