The invasive mucinous adenocarcinoma of the lungs (LIMA) is an uncommon histological subtype of the mucinous adenocarcinoma. In this article, we present the case of a patient with a very high cardiovascular risk profile, diagnosed with LIMA, pericardial tamponade due to secondary dissemination, and pulmonary embolism, whose management rouses many challenges. Despite receiving the correct anticoagulant and antiaggregant therapy, our patient developed repeated acute major cardiovascular events leading to a fatal outcome. To gather additional information on LIMA and the above cluster of pathologies, we performed the first research of the international medical literature for scientific articles published in the last eight years on PubMed, ResearchGate, Clarivate, and Google Scholar. As the first literature research failed to identify any case similar to our patient, we performed a second study of the same databases for subjects with lung adenocarcinoma instead of LIMA and the same comorbidities, and we found 10 cases. LIMA is a less frequent type of adenocarcinoma, with polymorphic radiologic appearances on the chest computed tomography, frequently mimicking pneumonia, and thus delaying the diagnosis and therapy. It has a worse prognosis and higher mortality than the common adenocarcinoma, but information on its secondary dissemination and complications is still required.