Dr. John Omar Mascarenhas, MD

Dr. John Mascarenhas is honestly amazing. From the very first visit, you can tell how knowledgeable and skilled he is, but what really makes him stand out is how much he truly cares about his patients. He always takes the time to listen, explains everything in a way that actually makes sense, and never rushes you. His calm and thoughtful way of doing things always puts me at ease. Plus, he’s super quick to respond to my emails, which I really appreciate. What I love most is how positive he is—he always brings a sense of humor to our conversations and encourages me every step of the way. I always feel like I’m in great hands with him. Everyone on his team is also super friendly, professional, and keeps things running smoothly. I’m so grateful for the wonderful care I’ve received and would absolutely recommend him to anyone looking for a caring and knowledgeable oncologist.

This Dr. is missing bedside manner. "I just prescribe, side effects are your problem." I had a severe side effect.

I am a patient and student, and Dr Mascarenhas is my physician. He happens to teach one of my classes and is one of the very best at Sinai. He is a role model and a kind person. Also very funny and quick witted!

Dr.Mascaranhaus is one of the best doctors I have ever met in my life!he is so caring,patient and has wonderful bedside manners. I highly reccomend him, if you need to see a specialist like him. He always makes time to talk to you,and explains everything that you need to know. Thank you Dr.Mascarenhaus for the wonderful care you have given me.

I was referred to him for a clinical trial - and he is kind, consistant, attentive- and even has a sense of humor.Almost 2 years later- I am much better- able to work and run my life.I thank him for his patience and attention

unique physician and highly regarded

highly recommend Dr. Mascarenhas and his team at Mount Sinai and their great research efforts.

Dr Mascarenhas treats my mother for a blood cancer and I am eternally greateful for the kindness he showed all of us. He has excellent bedside manner and clearly is a leader in his field.

Dr. Mascarenhas is the best doctor a patient could ask for. He listens and truly cares about his patients. He asks others for insight when needed and never makes patient feel uneasy about asking a question or having an opinion. I am truly blessed to have him as my doctor.

I saw many physicians in the city and nobody was able to diagnose my blood condition and i was getting sicker and clearly dying. Dr Mascarenhas saved my life. He listened to me, examined me and reviewed all my records. He easily spent 2 hours on my case in my first appointment. He had the courage to treat me where no other doctor felt comfortable and today I am enjoying a second lease on life. He is confident, at ease and very personable with a sense of humor that is rare and a modest nature that belies his inteliigence.