A 67-year-old woman underwent a medical check-up by her general practitioner after complaining of atypical pain in the shoulder girdle. Due to the important inflammatory syndrome noticed on blood testing, a polymyalgia rheumatica was suspected and she was started on corticosteroid treatment with good clinical response, but no impact on inflammation. She underwent extensive imaging with a thoraco-abdominal CT scanner that demonstrated a pancreatic mass, then later a PET-CT showed 3 different hyperactive lesions. Biopsies then revealed simultaneous diffuse large B-cell lymphoma (DLBCL), colorectal adenocarcinoma and pancreatic neuroendocrine tumour. She benefited from low rectal endoscopic excision of the colorectal tumour, R-CHOP chemotherapy for DLBCL and laparoscopic left pancreatectomy. Successful treatment required a good multidisciplinary collaboration between the different specialists. The patient made a good recovery and achieved complete remission at 1 year. This an unusual presentation of multiple primary malignancies.