hira.n
Regarding your 2 posts:
Some PP do what is the minimum required tests and send the results to CIC within a day or two. When CIC doctors see the reports, they may ask for further tests to be done. This turn-around takes about 2 months. Further more, most of the time, the "further tests" involve testing for active TB (this is found out by undergoing sputum tests). Sputum tests take about a month to complete (not very sure), as they need to take sample of sputum (first step), culture the bacteria and then compare it with a new sample of sputum (second step). Some PP proactively inform us about the spots in the xray (which most of the time is just normal anamoly but in rare cases could indicate active TB). The PP then takes the first step of taking the sputum test. In the meantime, they send the report to CIC. If CIC then gets back for further tests, you would have saved quite some time - as the results would already have been confirmed by then.
In short, do not worry if the doctor asks for further tests, just ensure they send the medical report within the time specified - you also ensure that the doctors provide you a copy of the Section A (filled by doctor).