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.

Table 2 Laboratory data during hospitalization

Parameter	Day 1	Day 7	Day 21	Reference range
Hb (g/dL)	64	37	21	130-175
PLT (109/L)	19	20	23	125-350
WBC (109/L)	5.8	3.5	7.4	3.5-9.5
RBC (1012/L)	2.19	1.17	0.60	4.4-5.8
RET%	10.63	14.76	---	0.5-1.5%
TBil (μmol/ L)	121.1	58.3	79.3	3.42-20.52
IBIL (μmol/L)	94.3	46.5	61.1	2-18
DBiL (μmol/L)	26.8	11.8	18.2	0.0-6.84
LDH (U/L)	1040	2226	1254	120-250
FIB (g/L)	0.6	1.35	0.69	2-4
PT (second)	33.4	20.3	24.8	11.0-14.5
Scr (μmol/L)	46	25	25	57-110
ADAMTS-13 activity	-	-	100	0-100%
ADAMTS-13 inhibitor	-	-	Negative	-/+

Hb: Hemoglobin; PLT: Platelet; RBC: Red blood cell; WBC: White blood cell; RET%: Reticulocyte percentage; TBil: Total bilirubin; DBiL: Direct bilirubin; IBIL: Indirect bilirubin; LDH: Lactate dehydrogenase; PT: Prothrombin time; FIB: Fibrinogen; Scr: Serum creatinine; ADAMTS-13: A disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13, involved in regulating blood clotting.

Table 3 Stratified management by organ system and core pathological mechanisms

Functional category	Drug	Dosage/administration	Mechanism of action
Blood component replacement	Leukocyte-depleted RBCs	17.5 U, IV infusion	Corrects anemia, improves tissue oxygenation
	Platelets	10 therapeutic units, IV infusion	Prevents thrombocytopenic bleeding
Hematopoietic regulation	Recombinant TPO	15000 U, IV infusion	Stimulates megakaryocyte differentiation
Coagulation correction	Human fibrinogen	2 g, IV infusion	Replenishes clotting factor I
Immunosuppression	Methylprednisolone sodium succinate	40 mg/day, IV infusion	Suppresses antibody-mediated RBC destruction
Capillary hemostasis	Carbazochrome sodium sulfonate	80 mg/day, IV infusion	Reduces vascular permeability
Hepatobiliary protection	Compound glycyrrhizin	120 mg/day, IV infusion	Anti-inflammatory, stabilizes hepatocytes
	Ursodeoxycholic acid	0.25 g, twice daily, per os	Promotes bile excretion
GI motility regulation	Mosapride citrate	5 mg, three times daily, per os	5-HT4 receptor agonist
	Omeprazole	1 g/day, IV infusion	Proton pump inhibitor
Broad-spectrum antibiotics	Ceftazidime	2 g, twice daily, IV infusion	Covers gram-negative bacteria
	Ornidazole	1 g/day, IV infusion	Targets anaerobes/protozoa
Bone protection	Zoledronic acid	4 mg/day, IV infusion	Inhibits osteoclast activity
Analgesic ladder	Tramadol ER	100 mg, every 12 hours, per os	Weak opioid + monoamine reuptake inhibition
	Morphine	3 mg/day, IV infusion	Central α-opioid agonist

RBC: Red blood cell; TPO: Thrombopoietin; GI: Gastrointestinal; ER: Extended release.