0130 GMT March 30, 2020
Vince Kitching, 69, booked an appointment with his GP straight after noticing it in his left breast, BBC wrote.
An ultrasound scan showed he had a tumor and he underwent a full mastectomy.
The grandfather-of-two from Llandudno Junction has now recovered after the discovery in May.
Breast cancer is very rare in men, with 390 diagnosed each year compared to 54,800 women, according to Cancer Research UK.
"Me and my wife Helen were devastated when we were told the news I had breast cancer," Kitching said.
But he said after surgery in Ysbyty Glan Clwyd he was able to go home the same day to recover.
He added: "I was very lucky as I didn't have any pain following my surgery and recovered very quickly."
A week later, he received the news from his surgeon that the cancer had not spread and he did not need any further treatment.
"I'm not too sure how long the lump had been there but I wasn't checking my breast area," Kitching said.
"In fact, like many men, I didn't even know we were supposed to check this area of our bodies.
"I had never heard of breast cancer in men before, there is no breast cancer in my immediate family so it had never crossed my mind."
Breast cancer is often thought of as something that only affects women, but men can get it in rare cases.
It develops in the small amount of breast tissue men have behind their nipples and usually occurs in the over 60s.
Kitching's surgeon Chiara Sirianni described male breast cancer as "quite rare" and said it represented about one percent of all cases.
She said: "It is important for men to remain aware and to report to the GP any new lumps on the breast or chest, especially if associated with skin changes and deformity.
"Most breast masses in men are benign, but they all warrant a specialist assessment."
Sirianni said 95 percent of male breast cancer cases are diagnosed at an early stage, however a "significant proportion" have a family history of the disease.