Hidden Stomach Cancer Unmasked by Rare Blood Syndrome That Destroyed Her Red Cells

A previously healthy 57-year-old woman walked into her doctor’s office with what looked like ordinary back pain. Within two weeks she was dead. The case, published in Clinical Case Reports, describes how a rare and devastating blood syndrome became the first visible sign of an aggressive, hidden stomach cancer that had already spread throughout her body. The report is a stark reminder that sometimes the blood tells a story long before any scan or symptom reveals the tumor driving it.

The patient’s ordeal began in April 2026, when she was referred to her general practitioner with back pain radiating down her right leg. She received a five-day course of intramuscular corticosteroids, a muscle relaxant, and the anti-inflammatory drug diclofenac. The treatment brought only slight relief, but something far more alarming appeared: extensive hematomas bloomed at every injection site. That unexpected bleeding prompted laboratory tests, and the results were grim. Her hemoglobin had crashed to 66 grams per liter, a level consistent with severe anemia, and her platelet count had fallen to 107 billion per liter, well below the normal range. Elevated bilirubin hinted that red blood cells were being destroyed somewhere inside her circulation.

By the time she was admitted to the hematology clinic the following day, the picture had crystallized into something hematologists recognize instantly and fear deeply. Her blood smear showed schistocytes, fragmented red cells sheared apart as they squeezed through obstructed microvessels, making up a staggering 30 percent of her red cell population. Lactate dehydrogenase, a marker of cell destruction, was massively elevated at 1744 units per liter. Haptoglobin, a protein that mops up free hemoglobin, was undetectable. The Coombs test was negative, ruling out autoimmune destruction. Her platelet count kept falling, dropping to 29 billion per liter within days. Everything pointed to thrombotic microangiopathy, a family of disorders in which tiny blood clots shred red cells and consume platelets throughout the body.

The leading suspect was thrombotic thrombocytopenic purpura, or TTP, a fulminant condition caused by severe deficiency of the ADAMTS13 enzyme, which normally cleaves ultra-large von Willebrand factor in the blood. The patient’s PLASMIC score, a validated prediction tool, came back at 6, indicating a high probability of TTP. Following standard practice, clinicians did not wait for the enzyme result. Plasma exchange, the lifesaving mainstay of TTP treatment, was started immediately alongside corticosteroids. But the therapy failed. Her clinical condition and laboratory parameters showed no improvement, and when ADAMTS13 activity finally returned it was completely normal at 108.4 percent. TTP was excluded, the plasma exchange was stopped, and the diagnostic search pivoted toward a far more sinister possibility: a secondary microangiopathic hemolytic anemia driven by an underlying malignancy.

Cancer-related microangiopathic hemolytic anemia, abbreviated CR-MAHA, was first described by Brain and colleagues in 1970, who distinguished it from other thrombotic microangiopathies by its association with disseminated cancer, particularly mucin-producing tumors of the stomach, breast, and lung. The proposed mechanism was grimly elegant: tumor emboli lodging in the microvasculature and in-situ thrombosis mechanically fragmenting erythrocytes as they traverse the damaged vessels. The syndrome remains rare, documented mainly in individual case reports and small series, but the largest systematic review, encompassing 168 cases, found that adenocarcinomas dominate the list of culprits. Gastric carcinoma led at 26.2 percent, followed by breast, prostate, and lung cancers. More than 90 percent of patients had metastatic disease, and bone marrow infiltration was documented in over 80 percent of assessed cases.

The clues in this patient’s blood work soon multiplied. Tumor markers came back dramatically elevated: carcinoembryonic antigen at 101.7 micrograms per liter and carbohydrate antigen 72-4 exceeding 500 units per milliliter, roughly seventy times the upper reference limit. A re-review of her spinal MRI revealed multiple metastatic deposits throughout every visualized vertebra and her pelvic bones. Computed tomography of the chest, abdomen, and pelvis showed bilateral adrenal enlargement and abdominal lymphadenopathy with nodes up to 25 millimeters across. Gastric biopsies, taken through an endoscope that revealed macroscopically normal mucosa, showed only chronic gastritis, a deceptive finding given what lay beneath. The decisive evidence came from the bone marrow itself.

Bone marrow aspiration revealed clusters of metastatic cells, several times the size of a neutrophil, with eccentric nuclei occupying about three-quarters of the cell volume and abundant pale cytoplasm. The trephine biopsy showed near-complete replacement of normal hematopoietic tissue by metastatic adenocarcinoma composed of discohesive cells stuffed with intracytoplasmic mucin that pushed their nuclei to the periphery, producing the classic signet-ring appearance that gives this tumor its name. Immunohistochemistry sealed the diagnosis: the cells expressed CK7, CK20, CDX2, MUC1, MUC2, and MUC5, while GATA3 was negative. This immunophenotypic profile, combined with the soaring CA 72-4 level, pointed squarely to a gastrointestinal primary, most consistent with metastatic gastric signet-ring-cell adenocarcinoma. Colonoscopy could not be performed because of her poor condition. Referred to oncology, she could not receive cancer-directed treatment because of persistent severe thrombocytopenia. She died six days later.

Why does this particular cancer trigger such catastrophic blood destruction? The answer appears to lie in mucins, the sugar-decorated glycoproteins that signet-ring-cell carcinomas manufacture in abundance. Mucins can bind P-selectin on platelets and L-selectin on leukocytes, promoting the formation of platelet-leukocyte aggregates that seed microvascular thrombosis, sometimes without conventional thrombin generation. The same interaction underlies Trousseau syndrome, the migratory thrombophlebitis that has haunted cancer patients since the nineteenth century. Many of these tumors also express tissue factor, releasing procoagulant microvesicles that generate thrombin and deposit fibrin diffusely, blurring the line with disseminated intravascular coagulation. Loss of E-cadherin, a hallmark of diffuse-type gastric cancer, facilitates the early peritoneal and bone marrow dissemination characteristic of signet-ring-cell tumors, whose thin-walled, highly permeable sinusoids may create microenvironments especially vulnerable to erythrocyte fragmentation.

The case carries a practical message for clinicians everywhere: when microangiopathic hemolysis fails to respond to plasma exchange and ADAMTS13 activity is normal, the workup must not stop. Tumor-marker assessment, cross-sectional imaging, and, crucially, bone marrow examination should follow promptly, particularly when unexplained cytopenias or a leucoerythroblastic blood picture suggest marrow involvement. In this patient, bone marrow aspiration provided the first direct evidence of metastatic carcinoma and substantially accelerated the diagnosis before histopathological confirmation. Distinguishing CR-MAHA from TTP and DIC matters enormously, because fibrinogen, coagulation times, D-dimer levels, and the response to plasma exchange all differ across these entities, and the treatments are fundamentally incompatible. Plasma exchange, a cornerstone of TTP therapy, offers no sustained benefit in CR-MAHA when the underlying malignancy remains untreated.

The story is ultimately a tragic one, but it is also a scientific one. It demonstrates how a single blood smear, read carefully, can expose an entire hidden pathology, and how the peculiar biology of a mucin-producing tumor can announce itself through the destruction of red blood cells rather than through pain, weight loss, or any symptom a patient might recognize. For a woman with back pain and no prior medical history, the interval from first symptom to fatal diagnosis was measured in weeks. The clinicians who reported her case hope that by documenting the diagnostic pathway, the laboratory red flags, and the pitfalls of anchoring on TTP, they can help the next patient reach a diagnosis early enough for cancer-directed therapy to begin while there is still time for it to matter.

Subject of Research: Cancer-related microangiopathic hemolytic anemia revealing occult metastatic gastrointestinal signet-ring-cell carcinoma

Article Title: Cancer‐Related Microangiopathic Haemolytic Anemia Revealing Occult Metastatic Gastrointestinal Signet‐Ring Cell Carcinoma: A Clinicopathological Case Report and Practical Differential Diagnostic Approach

Article References: Jovanovic, D., Sretenovic, S., Jovanovic, D., Ilic, M., & Djurdjevic, P. (2026). Cancer‐Related Microangiopathic Haemolytic Anemia Revealing Occult Metastatic Gastrointestinal Signet‐Ring Cell Carcinoma: A Clinicopathological Case Report and Practical Differential Diagnostic Approach. Clinical Case Reports, 14(10), Article e73675. https://doi.org/10.1002/ccr3.73675

Image Credits: AI Generated

DOI: 10.1002/ccr3.73675

Keywords: microangiopathic hemolytic anemia, signet-ring-cell carcinoma, gastric cancer, thrombotic thrombocytopenic purpura, ADAMTS13, bone marrow metastasis, mucin, tumor markers, disseminated intravascular coagulation, plasma exchange, schistocytes, case report