A case of occult colon cancer with sepsis as the primary manifestation guided by bone marrow puncture

Background: Bone marrow metastasis is common in liver cancer and lung cancer, but there are few reports on bone marrow metastasis of colon cancer. So far, there are no research reports from mainland China; especially reports of bone marrow metastasis combined with septic shock as the main manifestation are even rarer. Case presentation: A 71-year-old elderly woman with sepsis as the first symptom, mainly manifested as high fever, low blood pressure, high inflammation indicators, etc. CT examination revealed mild inflammation of the lungs and no obvious abnormalities in the abdomen. Blood culture culture suggested Escherichia coli and Aeromonas hydrophila/caviae. After anti-infective treatment, the patient's sepsis symptoms improved significantly, but after repeated platelet transfusion, he still could not correct hypothrombosis. Finally, a large number of malignant cells were found through a bone marrow puncture smear, and further PET-CT examination confirmed that the ascending colon malignant tumor was accompanied by multiple metastases such as the liver and bones. The patient was eventually unable to tolerate surgery due to bone marrow failure and liver failure and died 3 weeks after admission.Conclusions: We hope that this case report can raise people’s awareness of the insidiousness of colon cancer and the possibility of metastasis to the bone marrow, especially for patients with progressive thrombocytopenia that is difficult to correct. Thrombocytopenia needs to be treated differently from sepsis.