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

• Low-Grade Collecting Duct Carcinoma of Kidney
• Low-Grade Bellini Duct Carcinoma of Kidney
• TC-RCC (Tubulocystic Renal Cell Carcinoma)

What is Tubulocystic Renal Cell Carcinoma? (Definition/Background Information)

• Tubulocystic Renal Cell Carcinoma (TC-RCC) is a rare type of renal cell carcinoma (kidney cancer). It is a malignant tumor that develops due to an abnormality within the tissue lining in the collecting ducts of the kidney. The tumor consists of tubules, microcysts, and macrocysts, when examined under a microscope, by a pathologist
• Tubulocystic Renal Cell Carcinoma generally affects adult males and females; though, it is more common in older men. The exact cause of development of TC-RCC is presently unknown. But, the tumors are less aggressive and have good prognosis with adequate treatment
• The risk factors for developing the carcinoma are unidentified. However, the general risk factors for kidney cancers include a family history of kidney cancer, smoking, exposure to toxins, high blood pressure, obesity, and other factors
• The typical symptoms of Tubulocystic Renal Cell Carcinoma are blood in urine, a lump on the side of the abdomen, flank pain, unexplained fever, and unexplained weight loss. TC-RCC may give rise to complication such as the spread of cancer to other parts of the body. However, it rarely recurs, following surgery, and is known to very rarely metastasize
• The healthcare provider might diagnose the condition using blood tests, imaging studies, and tissue biopsy as necessary. Genetic testing may be required in some cases
• The treatment options include surgery, radiation therapy, chemotherapy, and targeted drug therapy. The prognosis of Tubulocystic Renal Cell Carcinoma depends on size of tumor and whether it is localized in the kidney or has metastasized (if TC-RCC is in its early or advanced stage, at the time of diagnosis)
• Although, Tubulocystic Renal Cell Carcinoma might not be preventable, being aware of one’s family history and having regular check-ups might help diagnose the cancer early. Leading a healthy lifestyle, managing an ideal body weight, controlling blood pressure, avoiding unnecessary medication, smoking cessation, and other such factors can potentially help one avoid cancer development

The 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
• Collecting duct carcinoma of kidney: They make up for approximately 1% of the kidney cancers. The cancer arises from the collecting ducts of the kidney

Who gets Tubulocystic Renal Cell Carcinoma? (Age and Sex Distribution)

• Tubulocystic Renal Cell Carcinoma affects both men and women (average age 54 years). However, TC-RCC is reported to be more common in men
• The cancer is not specific to any ethnic or racial group

What are the Risk Factors of Tubulocystic Renal Cell Carcinoma? (Predisposing Factors)

In a majority of individuals, no clear-cut risk factors for Tubulocystic Renal Cell Carcinoma have been established to date. Some studies have shown that the following factors may predispose an individual to kidney cancer development:

• Family history of kidney cancer: If the cancer is present among close family members, then the risk of developing the cancer is increased
• Obesity
• High blood pressure
• Smoking
• Exposure to toxins, such as naphthylamine dye, asbestos, lead, polycyclic aromatic hydrocarbons, cadmium, and other chemical compounds
• Continuous use of certain medications such as non-steroidal anti-inflammatory drugs
• Long-term dialysis

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 Tubulocystic Renal Cell Carcinoma? (Etiology)

Currently, scientists do not know the definitive factor(s) causing Tubulocystic Renal Cell Carcinoma. Studies have shown numerous genetic mutations in TC-RCC. Some of the mutations include:

• Gains in chromosome 7 (in 7p, 7q and trisomy 7)
• Gains in chromosome 17 (in 17p, 17q and trisomy 17)
• Loss of chromosome 4

Research is underway to well characterize these mutations.

What are the Signs and Symptoms of Tubulocystic Renal Cell Carcinoma?

Tubulocystic Renal Cell Carcinoma does not cause significant signs and symptoms in many individuals. The combination of signs and symptoms may also vary from individual to individual. The signs and symptoms associated with TC-RCC may include:

• Small tumors usually do not cause any symptoms. But, occasionally they may become painful, if they compress the surrounding structure
• Blood in the urine (hematuria)
• Fatigue due to anemia
• A visible lump may be seen on the side of the abdomen
• The tumors can be large, growing up to 17 cm in size
• Fluid accumulation in the lower legs (pedal edema)
• Flank pain
• Unexplained weight loss
• Night sweats, unexplained fever
• Generalized weakness and pain in the body
• 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)

The signs and symptoms may depend on the size of the kidney tumor.

How is Tubulocystic Renal Cell Carcinoma Diagnosed?

Many of the Tubulocystic Renal Cell Carcinoma tumors are diagnosed incidentally during imaging studies undertaken for some other health condition. A healthcare provider might employ one or several of the following tools to diagnose TC-RCC:

• Evaluation of the patient’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 (LFT’s)
• 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 Tubulocystic Renal Cell Carcinoma includes:
  • Collecting duct carcinoma: TC-RCC can histologically appear like collecting duct carcinoma; however, it has different mutations
  • Multilocular cystic renal cell carcinoma
  • Multilocular renal cyst/cystic neoplasm
  • Mucinous tubular and spindle cell neoplasm

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 Tubulocystic Renal Cell Carcinoma?

The possible complications associated with Tubulocystic Renal Cell Carcinoma include:

• Metastasis: The cancer can spread to other areas of the body, such as to the lung, liver and bone. However, metastasis is generally uncommon
• Rarely, 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 Tubulocystic Renal Cell Carcinoma Treated?

The treatment measures for Tubulocystic Renal Cell Carcinoma may include the following:

• 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, 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
  • Postoperative 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 Tubulocystic Renal Cell Carcinoma) after surgery
  • Radiotherapy can also be used as an additional therapy after surgery, if there is a possibility of tumor recurrence after surgery, or if there are inadequate margins following surgery (possibility of tumor left behind)
• Chemotherapy can be used for treating Tubulocystic Renal Cell Carcinoma under the following circumstances (depending on case by case basis):
  • The tumor cannot be removed completely (incomplete surgical resection)
  • Tumors that recur after surgery (recurrent TC-RCC)
  • Tumors that have spread to distant parts of the body (metastatic TC-RCC)
• Immunotherapy for Tubulocystic Renal Cell Carcinoma: A patient’s immune system is activated to combat the cancer in this kind of therapy.
• Targeted drug therapy for Tubulocystic Renal Cell Carcinoma: This kind of drug treatment targets and kills cancer cells specifically, not harming surrounding normal/healthy cells
• Arterial embolization of Tubulocystic Renal Cell Carcinoma 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 Tubulocystic Renal Cell Carcinoma be Prevented?

Current medical research has not established a method of preventing Tubulocystic Renal Cell Carcinoma.

• Regular health check-ups might help those individuals with a history of the condition in the immediate family and help diagnose TC-RCC early
• 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 Tubulocystic Renal Cell Carcinoma include reducing contributory risk factors, such as:

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

What is the Prognosis of Tubulocystic Renal Cell Carcinoma? (Outcomes/Resolutions)

The prognosis of Tubulocystic Renal Cell Carcinoma depends on the size and number of tumors, their localization, and spread. In general, the prognosis is good. The tumors are usually slow-growing and diagnosed at an early stage.

• The most reliable prognostic factor of TC-RCC 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. In majority of cases, the tumor is low stage.
  • The surgical resectability 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 Tubulocystic Renal Cell Carcinoma is diagnosed in the early stages, the possibility of survival increases 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, the possibility of prolonged survival following diagnosis is limited

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 Tubulocystic Renal Cell Carcinoma:

Please visit our Cancer & Benign Tumors Health Center for more physician-approved health information:

http://www.dovemed.com/diseases-conditions/cancer/