Graduated from University College Cork in 2002 and completed a master’s degree in surgery at Trinity College Dublin (2006). Commenced the higher surgical training programme in Urology, working in a variety of university hospitals throughout Ireland.

Awarded the FRCS (Urol) qualification in 2011. Embarked on an 18-month fellowship in Andrology and Genital Oncology in 2013 at the renowned Institute of Urology in University College Hospital London. Worked with international experts David Ralph, Suks Minhas, and Asif Muneer in all aspects of penis cancer treatment and Andrology. 

Currently a senior lecturer in the College of Medicine in University College Cork and Royal College of Surgeons, Ireland.

Mr. Cullen is a fellowship trained Urologist and Andrologist and with a specialist interest in the following: general urology, stone disease, prostate surgery, penis cancer surgery, penile implant, penile straightening surgeries, peno-scrotal reconstructive surgeries, and management of male factor infertility