Occult colon cancer with sepsis as the primary manifestation identified by bone marrow puncture: A case report

Bone marrow metastasis is common in liver and lung cancer, but there are few reports on bone marrow metastasis in colon cancer. To date, there are no such reports from mainland China, and reports of bone marrow metastasis with septic shock as the main manifestation are even rarer.

A 71-year-old woman with sepsis as the first symptom presented with high fever, low blood pressure and high inflammation indicators. Computed tomography (CT) examination revealed mild inflammation of the lungs and no obvious abnormalities in the abdomen. Blood culture suggested Escherichia coli, Aeromonas hydrophila and Aeromonas caviae infection. Antibiotic treatment significantly improved the patient's sepsis symptoms; however, her thrombocytopenia (TCP) could not be corrected despite repeated platelet transfusions. Many malignant cells were ultimately found following a bone marrow puncture smear, and further positron emission tomography/CT (PET/CT) examination confirmed that the malignant tumor in the ascending colon was accompanied by multiple metastases, including the liver and bones. Colon adenocarcinoma was confirmed by autopsy.

Patients with advanced colon cancer may not have typical clinical symptoms, and sepsis may be the first symptom. When patients have severe TCP that cannot be explained by sepsis of intestinal origin, it is necessary to be aware of the possibility of bone marrow metastasis of intestinal tumors. As such patients often cannot tolerate endoscopy, bone marrow biopsy smears or biopsy tests for specialized cells can help obtain a diagnosis, especially in less developed countries where PET/CT is scarce.