What are the other Names for this Condition? (Also known as/Symptoms)

• Bellini Duct Carcinoma
• Carcinoma of the Collecting Ducts of Bellini
• Renal Collecting Duct Carcinoma

What is Collecting Duct Carcinoma of Kidney? (Definition/Background Information)

• Collecting Duct Carcinoma of Kidney (CDCK) is a rare, aggressive type of renal cell carcinoma (a form of kidney cancer). It is a malignant tumor that develops due to an abnormality within the tissue lining in the collecting ducts of the kidney (which is a part of the kidney)
• Collecting Duct Carcinoma of Kidney generally affects adult males and females. The exact cause of development of CDCK is presently unknown, and the risk factors are not well-established
• The typical signs and symptoms of Collecting Duct Carcinoma of Kidney include blood in urine, a lump on the side of the abdomen, flank pain, unexplained fever and weight loss. The tumor may give rise to complications such as spreading of the cancer to other parts of the body
• The healthcare provider might diagnose the condition using blood tests, imaging studies and tissue biopsy as necessary. A genetic testing may be required in some cases
• The treatment options include surgery, radiation therapy, and targeted drug therapy. Chemotherapy is not known to be effective in treating Collecting Duct Carcinoma of Kidney
• The prognosis mainly depends on the size of tumor and whether it is localized to the kidney or has metastasized i.e., if the cancer is in its early or advance stages, at the time of diagnosis. In many cases, the prognosis of Collecting Duct Carcinoma of Kidney is poor
• It may not be possible to prevent CDCK; although, in general, leading a healthy lifestyle, maintaining an ideal body weight, controlling one’s blood pressure, avoiding unnecessary medication, and avoiding smoking are all factors that can potentially help one reduce the risk for cancer development

The other main types of kidney cancers include:

• Clear cell renal cell carcinoma: This is also called conventional renal cell carcinoma. 65% of all renal cancers belong to this type
• Papillary renal cell carcinoma (PRCC): It is also called chromophil renal cell carcinoma. It constitutes 15% of all renal cancers. Some of these cancers can be seen in syndromes such as hereditary papillary renal cell carcinoma syndrome. A majority of individuals with PRCC, do not have a family history of kidney cancer
• Chromophobe renal cell carcinoma: They make up for 5% of the renal cancers. Usually, it is a slower-growing cancer when compared to other kidney cancers

Who gets Collecting Duct Carcinoma of Kidney? (Age and Sex Distribution)

• 1-3% of cancers of kidney are Collecting Duct Carcinomas of Kidney
• These carcinomas affect individuals of all ages; the average age of diagnosis is 55 years
• It affects both men and women. However, this form of kidney cancer is more commonly reported in men (male-female ratio of 2:1)
• The cancer is not specific to any ethnic or racial group

What are the Risk Factors for Collecting Duct Carcinoma of Kidney? (Predisposing Factors)

• In many individuals, no clear-cut risk factors for Collecting Duct Carcinoma of Kidney have been established to date
• Some cases have been associated with analgesic nephropathy. It a medical condition resulting in kidney damage, due to an overuse of painkillers/analgesics

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your health care provider.

What are the Causes of Collecting Duct Carcinoma of Kidney? (Etiology)

Currently, scientists do not know the definitive factor(s) causing Collecting Duct Carcinoma of Kidney.

• Studies have helped detect numerous genetic mutations in CDCK. Some of these mutations include:
  • Loss of chromosome 8p, 16p, and 9p
  • Gains in chromosome 13q
• These genetic mutations may be responsible for tumor formation. Research is underway to well-characterize these mutations

What are the Signs and Symptoms of Collecting Duct Carcinoma of Kidney?

The combination of signs and symptoms vary from individual to individual. It may also depend on the size of the kidney tumor.

The signs and symptoms associated with Collecting Duct Carcinoma of Kidney may include:

• Blood in the urine (hematuria)
• A visible lump may be seen on the side of the abdomen; the tumor may vary in size from 1.5 cm to 19 cm (mean size of 7.7 cm)
• Fatigue, in some individuals, due to anemia
• Unexplained fever, night sweats
• Unexplained weight loss
• Generalized weakness and pain in the body
• Flank pain
• Fluid accumulation in the lower legs (pedal edema)
• Abnormal liver function test
• If the tumor is associated with paraneoplastic syndrome; then, the following may be noted:
  • Increased blood pressure (hypertension)
  • Increased calcium in blood (hypercalcemia)
  • Increased red blood cells (erythrocytosis)
  • Increased platelets (thrombocytosis)

Many tumors have metastasis at the time of diagnosis.

How is Collecting Duct Carcinoma of Kidney Diagnosed?

A healthcare provider might employ one or several of the following tools to diagnose Collecting Duct Carcinoma of Kidney:

• Evaluation of the individual’s personal and family medical history
• A complete physical examination
• Blood tests such as complete blood count (CBC), serum calcium, serum albumin, liver function test (LFTs)
• Urine analysis such as albumin levels
• Plain X-ray of the abdomen
• Ultrasound scan of the abdomen
• Computed tomography (CT) scans of the kidneys
• Magnetic resonance imaging (MRI) and positron emission tomography (PET) scans may help differentiate between benign versus malignant tumors, by detecting areas of metastasis (if any)

Although the above modalities can be used to make the initial diagnosis, a tissue biopsy of the tumor may be required to make a definitive diagnosis to begin treatment.

• The tissue for diagnosis can be procured in multiple different ways, and they include:
  • Fine needle aspiration (FNA) biopsy of the tumor: A FNA biopsy may not be helpful, because one may not be able to visualize the different morphological areas of the tumor. Hence, a FNA biopsy as a diagnostic tool has certain limitations, and an open surgical biopsy is preferred
  • Core biopsy of the tumor
  • Open biopsy of the tumor
• A tissue biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
• Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
• Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely electron microscopic studies to assist in the diagnosis
• The differential diagnosis of Renal Collecting Duct Carcinoma may include:
  • Clear cell papillary renal cell carcinoma
  • Cystic nephroma
  • Benign renal cortical cyst
  • Tubules cystic carcinoma

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Collecting Duct Carcinoma of Kidney?

The possible complications associated with Collecting Duct Carcinoma of Kidney include:

• Metastasis: The cancer can spread to other areas of the body, such as the liver, lungs, or bone
• Recurrence of the tumor due to its partial or incomplete surgical removal
• Complications due to surgery
• Side effects of chemotherapy (such as toxicity) and radiation

How is Collecting Duct Carcinoma of Kidney Treated?

Due to rarity of the tumor, treatment protocols for Collecting Duct Carcinoma of Kidney are not well-established. However, the following treatment measures may be considered:

• Surgery:
  • In majority of individuals, surgical resection of the tumor with clear margins may result in a cure, especially if the tumor is confined to the kidney. In some cases, due to location of the tumor (inaccessibility), a complete surgical removal may be difficult
  • Several different surgical procedures may be available, such as partial/radical nephrectomy or laparoscopic surgery, depending on the type, size, and location of the tumor
  • Post-operative care is important: One must maintain minimum activity levels, until the surgical wound heals
• Radiation therapy:
  • Radiotherapy can be used as primary therapy in situations where the tumor cannot be removed completely, or when the tumor reappears (recurrent Collecting Duct Carcinoma of Kidney) after surgery
  • Radiotherapy can also be used as an additional therapy after surgery, if there is a possibility of tumor recurrence, or if there are inadequate margins following surgery (possibility of tumor being left behind)
• In general, CDCK does not respond well to chemotherapy; but, it may be considered on a case-by-case basis and under the following circumstances:
  • The tumor cannot be removed completely (incomplete surgical resection)
  • Tumors that recur after surgery (recurrent CDCK)
  • Tumors that have spread to distant parts of the body (metastatic CDCK)
• Immunotherapy for CDCK: A patient’s immune system is activated to combat the cancer in this form of therapy
• Targeted drug therapy for CDCK: This form of drug treatment targets and kills cancer cells specifically, not harming surrounding normal/healthy cells
• Arterial embolization of Collecting Duct Carcinoma of Kidney is a possible treatment option. Here the blood supply to the tumor is blocked resulting in tumor death

A long-term follow-up is required, because recurrence of the tumor at the site of surgery or metastasis in distant sites, have been reported many years after surgery.

How can Collecting Duct Carcinoma of Kidney be Prevented?

• Current medical research has not established a method of preventing Collecting Duct Carcinoma of Kidney
• Regular medical screening at periodic intervals with blood tests, radiological scans, and physical examinations for those who have already endured the tumor are helpful

In general, preventive methods for Collecting Duct Carcinoma of Kidney include reducing the contributory risk factors, such as:

• Smoking
• Unhealthy diet and lifestyle
• Obesity
• Exposure to toxins
• Unnecessary medication

What is the Prognosis of Collecting Duct Carcinoma of Kidney? (Outcomes/Resolutions)

The prognosis of Collecting Duct Carcinoma of Kidney depends on the size of the tumor and success of surgical removal. In general, the tumors grow rapidly and have tendency to spread in the body.

• The most reliable prognostic factor is dependent on whether the tumor can be completely removed through surgery with free margins or not (no traces of the tumor in adjoining tissue)
• In general, the prognosis also depends upon a set of several factors, which include:
  • Stage of tumor: With lower-stage tumors, when the tumor is confined to site of origin, the prognosis is usually better with appropriate therapy. In higher-stage tumors, such as tumors with metastasis, the prognosis is poor
  • The surgical respectability of the tumor (meaning, if the tumor can be removed completely)
  • Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
  • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
  • Whether the tumor is occurring for the first time, or is a recurrent tumor. Recurring tumors have worse prognosis compared to tumors that do not recur
  • Response to treatment: Tumors that respond to treatment have better prognosis compared to tumors that do not respond to treatment
• When Collecting Duct Carcinoma of Kidney is diagnosed in the initial stages, the survival rates are increased and the prognosis is considered good with treatment
• In cases where both kidneys are affected, the prognosis is not projected to be favorable. Additionally, if the cancer has spread to other parts of the body, such as to the liver, lungs, or bone, prolonged survival following diagnosis is adversely affected
• In most of the cases, the prognosis of CDCK is poor due to its aggressive nature

As with any tumor, it is important to have follow-up appointments with a physician to monitor for any returning tumors.

Additional and Relevant Useful Information for Collecting Duct Carcinoma of Kidney:

• Analgesic nephropathy is defined as the damage to the kidneys, due to an overuse of painkillers (analgesics), such as acetaminophen, aspirin, ibuprofen, etc., which may occur over a prolonged period

The following article link will help you understand analgesic nephropathy:

http://www.dovemed.com/diseases-conditions/analgesic-nephropathy/