Surgeon who specializes in tuberous breasts in the GTA?

Thank you for the important question; careful selection of plastic surgeon will be the most important decision you make. 
 Although I cannot provide you with specific names, I would suggest starting with the your national Society of Plastic Surgery and/or the Aesthetic Society of Plastic Surgery to obtain a list of well experienced board-certified plastic surgeons.Then, I would suggest you visit a few surgeons whose practices concentrate on aesthetic surgery. 
***Ask to see lots of examples of their work and preferably speak/see patients who have had similar procedures done. Basically, patients should look at the overall "quality" of the outcomes achieved;  in other words, it will be important that patients see lots of examples of outcomes that they would be pleased with.  In doing so patients will be able to get an idea of each  plastic surgeon's "aesthetic sensibilities". 
 
Generally speaking, some of the characteristics seen with tuberous breasts include a very narrow base, short distance from areola to inframammary fold, tight (constricted) lower pole of the breasts, relatively wide space between the breasts, "puffy” areola and some degree of ptosis (drooping). 
Generally, correction of tuberous breast anomalies involves breast augmentation with areola reduction / mastopexy procedure. The distance from the inframammary fold is increased (to create a more rounded out appearance). Proper implant positioning improves the distance (cleavage) between the breasts. The areola reduction helps to treat the pointed and "puffy" appearance of the areola.
I hope this, and the attached link (dedicated to corrective surgery for patients with tuberous/constricted breasts) helps. Best wishes.

I would say that the majority of plastic surgeons performing breast surgery have experience with tuberous breasts. You are best to start with the ASPS or ASAPS or Canadian Plastic Surgery society website.