The Mediport Paradox: Mediastinitis and Pericardial Effusion With a Misplaced Mediport.

Totally implantable subcutaneous devices (TISDs) have become excellent options for patients requiring long-term chemotherapy, parenteral nutrition, and fluid replacement. As with all invasive devices and procedures, they come with their inherent risks, which may manifest immediately or at a later point in time. We present the case of a 74-year-old female with a history of hypertension, chronic obstructive pulmonary disease (COPD), ischemic stroke, breast cancer, and lung cancer who had mediport placement for chemotherapy administration. She received several infusions of pembrolizumab through her mediport and developed progressive dyspnea over four weeks. Upon evaluation at our institution, she was found to have a misplaced mediport with mediastinitis and pericardial effusion due to direct mediastinal exposure to immunotherapy. This case highlights the importance of systematic imaging review, regardless of suspected pathology, and encourages providers to have a low threshold to re-evaluate patients after device placement or immunotherapy commencement.