Microangiopathic Hemolytic Anemia as the Initial Presentation of Metastatic Signet-Ring Cell Carcinoma of the Colon: A Case Report

Microangiopathic hemolytic anemia (MAHA) is a condition characterized by intravascular fragmentation of red blood cells, leading to the characteristic finding of schistocytes on a peripheral blood smear. The differential diagnoses of MAHA include thrombotic thrombocytopenic purpura (TTP), hemolytic-uremic syndrome (HUS), disseminated intravascular coagulation (DIC), idiopathic thrombocytopenic purpura (ITP), infections, malignancies, and solid organ transplantation. The commonly associated malignancies with MAHA are gastric, breast, prostate, lung, and lymphoma. Signet-ring cell carcinoma (SRCC) of the colon is a rare form of cancer and is associated with a very poor prognosis. SRCC often presents at an advanced stage, with symptoms such as altered bowel habits, abdominal pain, distension, and potential bowel obstruction or perforation. We report a case of a 51-year-old female who presented with hemolytic anemia, thrombocytopenia, and schistocytes on her peripheral blood smear. In the setting of a high PLASMIC score, she was initially treated for TTP without improvement, warranting further evaluation, and was ultimately diagnosed with SRCC of the colon.