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

Table 1 Clinical timeline and disease progression analysis in gastric cancer (patient timeline: July 2023 - November 2024)

Date	Key event	Clinical details	Disease phase
July 10, 2023	Symptom onset	Hematemesis prompting hospitalization	Initial diagnosis phase
July 29, 2023	Imaging evaluation	Multidetector CT: Thickened gastric wall (lesser curvature), retroperitoneal lymphadenopathy
July 31, 2023	Definitive diagnosis	Endoscopic biopsy: Adenocarcinoma of the cardia (signet-ring cell carcinoma)
August 7, 2023	Surgical intervention	Total gastrectomy with Roux-en-Y esophagojejunostomy	Local therapy phase
Postoperative	Histopathological findings	Moderately-to-poorly differentiated adenocarcinoma (5 cm × 5 cm × 0.8 cm), invasion to subserosa, LN metastasis (11/31)
August 2023 to November 2023	Adjuvant chemotherapy	S-1 monotherapy (tegafur/gimeracil/oteracil), 2 cycles (40 mg/m² bis in die, days 1-14)	Adjuvant therapy phase
December 2023 to April 2024	Intensive chemotherapy	Oxaliplatin + S-1 (SOX regimen), 6 cycles (every 3 weeks)	Systemic therapy phase
Interim	Treatment complication	Myelosuppression (managed with G-CSF support)
April 2024 to September 2024	Maintenance therapy	S-1 monotherapy (60 mg bid, days 1-14, every 3 weeks)	Disease stabilization phase
October 23, 2024	Disease progression	New-onset lower back pain (NRS 5/10)	Recurrence/metastasis phase
November 6, 2024	Confirmatory imaging	Thoracolumbar MRI: T9/T10/L5 vertebral collapse, bone marrow infiltration (suggestive of metastases)

CT: Computed tomography; MRI: Magnetic resonance imaging; G-CSF: Granulocyte colony-stimulating factor.