Bone marrow metastasis of gastric signet ring cell carcinoma complicated by thrombotic microangiopathy: A case report.

Background: Thrombotic microangiopathy (TMA) is an acute syndrome characterized by microangiopathic hemolytic anemia, thrombocytopenia, and multi-organ dysfunction due to the microcirculation of platelet thrombi. Cancer-associated TMA is a rare and fatal complication, which often occurs during cancer remission. It is frequently misdiagnosed because of limited clinical awareness.

Case summary: A middle-aged female patient presented to our clinic with a 15-days history of back pain, 15 months post-gastrectomy. Cancer-associated TMA was confirmed through bone marrow aspiration, biopsy, and imaging. The patient received intermittent transfusions, fluids, nutrition, and microcirculation therapy with partial coagulation improvement. The family refused intensive care unit admission and plasma exchange, preferring palliative care. The patient died of cerebral hemorrhage and herniation due to disease progression. This case indicates that TMA may serve as an early manifestation of various malignancies, particularly gastric cancer. However, it is often misdiagnosed. Its pathogenesis is not well understood and needs to be further investigated. Currently, no standardized treatment have been developed. Plasma exchange is the only intervention available, though other therapies may also be effective.

Conclusion: In this case of gastric signet-ring cell carcinoma complicated by TMA, the patient achieved transient remission with supportive care but died following treatment discontinuation. Further studies are needed to elucidate the pathological mechanisms and therapeutic strategies for cancer-associated TMA.