Do doctors see a lot of patients with breast fat necrosis?

No. Fat necrosis in the breast is usually the result of tramatic injury. This is also self limited. Surgery to the breast(enhancement, reduction, lumpectomy, biopsy, etc) can result in tissue damage that can manifest as fat necrosis - that is usually self limited. In 20 years, I have seen one patient with fat necrosis in the hip/buttock - that was due to impact trauma. I've not seen it in the breast.
Rare. My only case was related to a nipple piercing, most likely an infectious origin and not true necrosis though. Patient lost 2/3 of her breast.

Related Questions

Palpable lumpin breast. Mammo-benign calcification biradsiii. Fnac-inflammatory lesion possibility of fat necrosis. Lump reduced. Taking antibiotics. Next?

See your doctor. For follow up. Resolution of a benign inflammatory breast nodule is good news. May repeat breast ultrasound in a few months to confirm complete resolution, and mammogram in 6 months. Read more...