Chromophobe renal cell carcinoma

There is limited information on how quickly chromophobe renal cell carcinoma develops. It is often difficult to determine how quickly a tumor has developed, because each individual tumor is unique and the speed of growth can vary among tumors of the same type. One study examined 6 chromophobe renal cell carcinomas. Of these, four were classified as slow-growing and two as fast-growing.

Birt-Hogg-Dube syndrome (BHDS) is a rare, complex, genetic disorder with three main clinical findings: non-cancerous (benign) skin tumors; lung cysts/history of pneumothorax; and various types of renal tumors. Chromophobe RCC is one of the more common types of renal tumors seen among patients with BHDS. Lipomas have been reported in patients with BHDS, albeit rarely.

Due to your husband's RCC and lung cyst, a consultation with a genetics professional may be helpful for evaluation of BHDS. During this visit, a genetic counselor or medical geneticist will likely obtain a detailed medical and cancer history, and a comprehensive family history (in particular looking for other relatives with renal cancer or the other features of BHDS). If it seems that your husband's personal medical history and family history are suggestive of BHDS, then genetic testing for diagnosis of BHDS can be discussed. Genetic professionals have training and expertise in reviewing the risks, benefits, and limitations of genetic testing, ordering the appropriate genetic test, and interpreting the results.

BHDS is caused by mutations in the FLCN gene. To date, FLCN is the only gene known to be associated with this syndrome. BHDS is inherited in an autosomal dominant manner. Some people with BHDS have an affected parent, and some have BHDS as the result of a new mutation in the FLCN gene that occurred around the time of conception (referred to as a "de novo" mutation).

Genetic testing of the FLCN gene identifies disease-causing mutations in most patients who have features consistent with BHDS. However, 7%-9% of patients who fulfill the clinical criteria for BHDS do not have an identifiable mutation in the FLCN gene.

Genetics clinics are a source of information for individuals and families regarding genetic conditions, treatment, inheritance, and genetic risks to other family members. More information about finding and visiting a genetics professional is available from the Genetic Consultation Handbook developed by Genetics Home Reference.

To find a genetics clinic, we recommend that you contact your primary healthcare provider for a referral. The following online resources can also help you find a genetics professional in your community:

• National Cancer Institute Cancer Genetic Services Directory lists professionals who provide services related to cancer genetics, including cancer risk assessment, genetic counseling, and genetic susceptibility testing.
• GeneTests offers a searchable directory of U.S. and international genetics and prenatal diagnosis clinics.
• The National Society of Genetic Counselors provides a searchable directory of US and international genetic counseling services.
• The American College of Medical Genetics has a searchable database of US genetics clinics.
• The University of Kansas Medical Center provides a list of US and international genetic centers, clinics, and departments.
• The American Society of Human Genetics maintains a database of its members, which includes individuals who live outside of the United States. Visit the link to obtain a list of the geneticists in your country, some of whom may be researchers that do not provide medical care.

Chromophobe renal cell carcinomas (RCC) are often larger than other types of kidney cancer at the time they are diagnosed. Though large size is generally a sign that a tumor is more concerning, many chromophobe RCCs are thought to be less aggressive than other types of RCC.

Stec R, Grala B, Maczewski M, Bodnar L, Szczylik C. Chromophobe renal cell cancer - review of the literature and potential methods of treating metastatic disease. J Exp Clin Cancer Res. 2009 Oct 7;28:134.