Unexpected outcome of a sigmoid lesion believed to be malignant

A 69-year-old male with a past medical history of an Olfactory nerve meningioma and left-sided Bell's palsy presented with 6 weeks of lower abdominal pain and weight loss of 4 kg in 6 months. His current medications included acetylsalicylic acid 80 mg once daily, Amlodipine 5 mg once daily and Allopurinol 300 mg once daily. Physical examination was benign without signs of acute abdomen. The abdomen was nondistended and soft but tender to palpation over the left lower quadrant. Laboratory studies showed no acute outliers. The patient was followed up by his pulmonologist because of thoracic lesions which required a PET-CT for further evaluation. This PET-CT revealed a focal zone of oedematous rectosigmoid colon with a strong suspicion of a semi-circular sigmoid neoplasia with continuation to the bladder (Figure 1a). A presumptive diagnosis of a primary colonic malignancy was made. Colonoscopy was performed and visualised a foreign linear object lodged in both walls of the diverticular sigmoid with surrounding inflammation, but otherwise normal mucosa (Figure 1b). No arguments could be made endoscopically to support the diagnosis of an underlying primary colonic malignancy.