PET/MRI in the Early Diagnosis of Extra-Nodal Primary Colonic Lymphoma: A Rare Case Presentation

Positron emission tomography (PET) integrated with MRI (PET-MRI) offers a superior imaging modality combining functional and metabolic insights with exceptional soft tissue contrast, without ionizing radiation exposure. This case report discusses a rare presentation of extra-nodal primary colonic lymphoma involving the cecum and ascending colon, leading to hollow viscus perforation. A 55-year-old male with a history of diabetes mellitus presented with abdominal distension and weight loss. Initial imaging revealed a right lumbar mass with associated cecal wall dehiscence and peritoneal collections. PET/MRI, preferred over PET/CT due to renal impairment, provided critical diagnostic insights. Histopathological findings confirmed a lymphoproliferative disorder. The patient underwent laparotomy, peritoneal lavage, and loop ileostomy. This case underscores the significance of early diagnosis using advanced imaging techniques like PET/MRI in managing rare gastrointestinal lymphomas, particularly in high-risk populations, to prevent life-threatening complications such as perforation peritonitis.