Dismissing it as a cyst, he had carried on with his day. Were it not for his family's insistence, Mr Rhall admits, he might not be here today.
They had bullied him into submission, picking up the phone to make that first call. Eighteen months on, and with a 2.5cm tumour removed, he is so very grateful that they did.
"They probably saved my life," said the 50-year-old from Meanwood. "If they hadn't forced me into making that first doctor's appointment, I would almost certainly have left it.
"I'm just glad they did. You've got to check, and you've got to pick the phone up and make that call, if you're worried.
"It's just a tiny chance it could be cancer, but unfortunately I was that one per cent. I'm coming out the other side, I'm still fighting. I just want other men to know the risks."
Diagnosis and surgery
It was May last year when Mr Rhall's girlfriend Shirelle Hinds had noticed the lump, near his left nipple. Knowing how stubborn he was, she had called his sister for help.
Later that same day, when Mr Rhall arrived at his parents' house, his sister was waiting to ambush him.
"'What's this about a lump then?', she had asked, and Mr Rhall, resigned, had agreed to meet with doctors, undergoing a mammogram, ultrasound and biopsy.
A week later, in a quiet room at Harrogate District Hospital, a surgeon had broken the news.
"They sat me down and said 'you've got cancer'. Just like that. I nearly fainted, fell off the chair. I'd never heard of breast cancer in men. I didn't know anything about cancer at all.
"My mind just went blank, on hearing that word. They asked if I had any questions, but I couldn't even speak."
The surgeon, accompanied by a MacMillan nurse, had explained that the cancer had been caught very early, at stage one, with a very strong chance of recovery.
"He was being positive," said Mr Rhall. "I couldn't really take it in. The surgeon just said 'don't worry - I've got this'. I was right down, but he brought me halfway back up."
Mr Rhall was to have the tumour removed in day surgery, waking to find the surgeon peeking into his room.
"He put his head round the door and winked at me, saying 'I told you I had this'. I could have hugged the man."
Mr Rhall, although still in recovery, looks the picture of good health. The former forklift truck driver will take a tablet every day for five years, and has a check up every June.
There is still support, firstly from the Sir Robert Ogden MacMillan Centre in Harrogate, then from the Breast Cancer Haven charity in Leeds.
Sitting in the charity's waiting room, he had been acutely aware that he was the only man there. It was later to emerge that he was the first man to walk through its doors.
In March, when he stepped onto the catwalk at the charity's fashion show fundraiser, he was to be blown away by the cheers of support.
"Pick up the phone, make the appointment," he says today. "I could feel it, there was a lump, not much bigger than a frozen pea.
"I just thought it was a cyst, it wasn't irritating me or bugging me. But I was scared, I was frightened.
"It could have been a cyst, it could have been nothing, or it could have been cancer. I got the worst news. But on the other hand, it was caught early.
"I just want men to check more regularly. It can happen. The hardest thing is picking up the phone to make that doctor's appointment.
"But if you don't, it could be too late, and you may have just months. The main thing is to catch it early."
Amrik Rhall is speaking out about his experience as a national awareness campaign is launched by breast cancer charity Walk the Walk.
The Men Get Breast Cancer Too! campaign, launched earlier this month, highlights the importance of men checking for symptoms, with a 'check your chest' poster.
Every year, 370 men are diagnosed with breast cancer in the UK, and around 81 men die of the disease.
Some of those affected joined forces this month to launch the campaign.
Nina Barough, founder and executive of Walk the Walk said: “It is such a privilege for Walk the Walk to be working with these incredibly brave men, who are prepared to share the emotional and very different ways that breast cancer has affected their lives.
"Their courage is born from their passion to help raise awareness and to encourage other men to be more aware of just how important it is to check their chest.
"Although less men than women are diagnosed with breast cancer each year, the mortality rate for primary breast cancer in men is high in comparison, due to lack of awareness and late detection."
Professor Stephen Johnston, consultant medical oncologist and a trustee of Walk the Walk said: “Similar to breast cancer diagnosis in women, if detected early it is a very treatable and curable disease in men.
"Although rare it is important to spread the word that men can get breast cancer too, and should 'check their chest'."
Walk the Walk are the organisers of The MoonWalk London, a night-time fundraising event, when women and men wearing brightly decorated bras walk a half or full marathon at Midnight. The MoonWalk London 2020 takes places on Saturday May 16. Sign up at www.walkthewalk.org