Pilgrims at Vatican's St Peter's Square expressed their sadness as well as best wishes to Pope Leo on Wednesday (October 14), the morning after it had been revealed that the pontiff's lung surgery on Tuesday (October 13) had resulted in the diagnosis of a pulmonary adeocarcinoma, a benign cancer in the lung.

Adenocarcinoma is a type of cancer that forms in glandular cells, which produce substances such as mucus. In the lungs, it develops in cells lining the air sacs and is the most common subtype of non-small cell lung cancer (NSCLC), the category that accounts for about 80%-85% of lung cancers. Adenocarcinoma represents roughly 40% of all lung cancer cases, according to the Lung Cancer Foundation of America.

It is typically found in the outer parts of the lungs and tends to grow more slowly than some other forms of lung cancer, increasing the chances of detection before it has spread.

The standard operation is a lobectomy, as occurred on Tuesday, in which an entire lobe of the lung is removed. Doctors consider it the preferred treatment when the tumor is limited to a single lobe because it maximizes the chances of removing all cancerous tissue while preserving as much lung function as possible.

Depending on the stage of the disease, treatment can also include chemotherapy, radiotherapy, targeted drugs and immunotherapy.

The Vatican has not given any information yet on what follow-up treatment the Pope might need.

DESCRIPCIÓN DE IMÁGENES

SHOWS: VATICAN CITY (OCTOBER 14, 2026) (REUTERS - Access all)

1. VARIOUS OF PEOPLE WALKING AT ST PETER’S SQUARE

2. POSTCARDS SHOWING POPE LEO

3. ST PETER’S SQUARE IN MORNING SUNLIGHT

4. PILGRIMS WAITING IN LINE

5. PILGRIMS LISTENING TO MASS

6. PEOPLE WALKING AT ST PETER’S SQUARE

7. TOURISTS TAKING PHOTOS

8. VARIOUS OF PEOPLE WALKING TOWARDS MASS

9. VARIOUS OF SOUVENIR SHOP AT ST PETER’S SQUARE

10. VARIOUS OF NEWSPAPERS HEADLINING ABOUT POPE LEO’S CANCER DIAGNOSIS

11. SOUNDBITE (German) PILGRIM FROM AUSTRIA, WILHELM PALZENBERGER, SAYING:

"It was sad news for us, of course, we were expecting to see him today during the Holy Mass, unfortunately, that is not going to happen, but I’m sure it is still going to be a wonderful mass.”

12. SOUNDBITE (English) PILGRIM FROM THE U.S., VALERIE MILLER, SAYING:

"I was very concerned. What I first heard was, I thought it was benign. But then we heard that after they went it, they found it was cancerous, so I know enough about cancer that it is encapsulated and so it looks like he is going to be okay. So that was good news.”

13. SOUNDBITE (English) PRIEST FROM SOUTH AFRICA, FATHER MTSHE NGI SENI, SAYING:

"I was looking forward to see him. But because he is sick, I said, let me just pray for the Holy Father. And I heard the good news today that he is well, the surgery went well, so I’m very glad to God that he has given us this shephard who is Pope Leo.”

14. SOUNDBITE (German) PILGRIM FROM AUSTRIA, CAECILIA PALZENBERGER, SAYING:

"It is always very bad news to receive such a diagnosis, but I wish him all the best and hope everything will be fine and that he will soon be back for us and all the people.”

15. SOUNDBITE (English) PILGRIM FROM THE U.S., MONICA, SAYING:

"Healing. Healing and recovery, yeah.”

16. PRIESTS TALKING IN FRONT OF ST PETER’S BASILICA

17. DOME OF BASILICA

18. PEOPLE STANDING IN FRONT OF BASILICA