You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Stipple sign in transitional cell carcinoma of the renal collecting system is best demonstrated by – and explain in detail?
The stipple sign refers to tracking of contrast into the interstices of a papillary lesion. This is seen in Intravenous urography (intravenous pyelography) of transitional cell carcinoma of renal collecting sysym. Other signs on IVP are filling defect; Calyceal obliteration & amputation; hydronephrosis with soap bubble nephrogram.