Vol. 6 Issue 3 Part A

RET (Rearranged during Transfection) is a transmembrane receptor protein-tyrosine kinase commonly associated with non-small cell lung adenocarcinomas, particularly those harboring RET fusion proteins ^[1]. Selective kinase inhibitors, such as Selpercatinib, have been developed to target RET tyrosine kinase receptors with higher specificity, aiming to improve treatment outcomes and reduce side effects compared to multitarget tyrosine kinase inhibitors ^[2]. Some of the side effects that have been reported with Selpercatinib are dry mouth, diarrhea, elevated liver enzymes, hypertension, prolonged corrected QT interval, fatigue/asthenia and abdominal pain ^[1]. While intestinal lymphangiectasia has been reported as a rare complication of multitarget tyrosine kinase inhibitors, to our knowledge, this is the first report of intestinal lymphangiectasia in a patient receiving the new generation of kinase inhibitors (Selpercatinib), which is considered a selective kinase inhibitor. We present the clinical presentation, diagnostic evaluation, and implications of this unique case. Due to the rarity of this complication and the presence of nonspecific symptoms, diagnosis can be difficult or delayed. Raising awareness about this rare complication can facilitate early diagnosis and improve care for cancer patients receiving Selpercatinib or similar targeted therapies.