Cancer itself can be diagnosed under many different circumstances very quickly. For example often times someone will come into the hospital with vague symptoms such as chest pain, shortness of breath, weight loss, or abdominal pain. A CAT scan will be done which may show spots of cancer in different parts of the body. This means that the person can be diagnosed with cancer very quickly (within a few hours of showing up to the hospital). However, there is no way to tell for sure what type of cancer one has just on a CAT scan.
To fully diagnose a specific type of cancer, there must always be a biopsy of the cancer with analysis under a microscope. This is where a doctor
places a needle into a tumor, or where a surgeon
cuts out a piece of a tumor so that it can be identified. This part of the diagnosis is important because it dictates what type of treatment will be given, and what prognosis the patient has.
This is the type of question that can be directed towards your primary care physician
. If you have any concerning symptoms, he or she can order imaging such as a CAT scan, to look for anything abnormal.