Brief Answer:
Biopsy should be done.

Detailed Answer:
Hi,
Thanks for choosing HealthcareMagic for your query.

As per your query,
Cysts can be benign (non-cancerous) or malignant (cancerous). Cysts are mostly not cancerous however in some case they can be cancerous.

As per the reports of the patient, a biopsy sample should be taken from the cyst to see if the cyst is benign or malignant.

Ultrasound guided Needle biopsy is most commonly used these days After an anesthetic is given, the surgeon inserts the biopsy needle into the kidney to get a sample. Ultrasound or computerized tomography (CT scan) may be used to guide the needle. Most kidney biopsies are done using this technique.

The tissue taken will be examined under the microscope to see if the growth is noncancerous or cancerous.

Simple kidney cysts (benign) that are causing symptoms or blocking the normal flow of blood or urine through the kidney may need to be treated using a procedure called sclerotherapy, where the cyst is punctured using a long needle, guided by ultrasound.

However, treatment of malignant cyst often depends on the stage of malignancy and lymph node involvement. Usually nephrectomy(removal of the kidney) is done (first line therapy) followed by chemotherapy of 6 months to one year.

So you should proceed with biopsy in this case.

Hope I answered your query, feel free for follow up questions I would be glad to answer.

Regards

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Brief Answer:
Follow up answer.

Detailed Answer:
Hi again,
In case you don't want to go for biopsy right now.I would suggest you to go for a test called urine routine and microscopy.Some times small cyst can be because of infection in urinary tract.Urine routine and microscopy will make things clear.
Small cysts are usually benign but can be malignant.To be on safe side we can go for a biopsy.
Why to keep a doubt in mind when we have all facilities!

Regards.

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