What Conditions Can Mimic Myelodysplastic Syndrome?

Because symptoms like fatigue and low blood counts are common in myelodysplastic syndrome (MDS), it is easy to assume that abnormal-looking bone marrow cells automatically confirm the diagnosis. However, dysplasia (abnormal-looking cells) and cytopenias (low blood cell counts) are not unique to MDS. Many other conditions—including nutritional deficiencies, medication side effects, infections, autoimmune diseases, and other bone marrow disorders—can suppress your bone marrow and cause your cells to look abnormal.

These “mimics” are potentially treatable or reversible contributors, and clinicians must carefully evaluate them before diagnosing a true myeloid neoplasm (blood cancer) like MDS ^[1]. It is also possible for these conditions to coexist with MDS, explaining only part of your abnormal counts.

Safety Warning: If you experience a fever while your white blood cell count is low (neutropenia), uncontrolled bleeding, severe shortness of breath, or rapidly worsening weakness, seek immediate medical attention. Never stop a prescribed medication or delay MDS care without speaking to your care team.

Nutritional Deficiencies

Nutritional imbalances can cause bone marrow changes that resemble MDS, but diagnosing and correcting them should always be guided by a clinician.

• Vitamin B12 and Folate: Severe deficiencies in these vitamins can cause low blood counts and marrow changes that closely resemble MDS ^[2]. If your B12 levels are borderline, your doctor might check your methylmalonic acid (MMA) and homocysteine levels. However, these tests require careful interpretation, as kidney dysfunction can also elevate MMA ^[2].
• Copper Deficiency and Zinc Excess: This is an important, frequently overlooked mimic ^[3]. Low copper can cause anemia, low white blood cell counts, and ring sideroblasts (developing red blood cells with an abnormal ring of iron around the nucleus) ^[3]. Copper deficiency is often linked to prior gastric surgery, malabsorption, or excess zinc ^[4]. Taking excess zinc—from dietary supplements or zinc-based denture adhesives—blocks copper absorption ^[3].
• Iron and Thyroid Issues: Severe iron deficiency, iron overload, and hypothyroidism can also contribute to abnormal blood counts and must be evaluated.

Medications, Toxins, and Liver/Kidney Disease

Everything you ingest—and how your organs process it—affects your blood.

• Medications: Certain medications, such as immunosuppressants, antibiotics, or previous chemotherapy, can suppress your bone marrow ^[5]. Never abruptly stop a prescription medicine on your own. Your doctor will review your medication list and may safely pause or substitute a suspected drug while monitoring your blood counts over time ^[5].
• Liver Disease and Alcohol: Heavy alcohol consumption and liver cirrhosis can cause low blood counts without primary bone marrow disease ^[6]. For instance, cirrhosis can lead to an enlarged spleen that traps platelets, lowering your counts ^[6].
• Kidney Disease: Chronic kidney disease is a common cause of anemia because damaged kidneys produce less erythropoietin (a hormone that stimulates red blood cell production) ^[7]. This typically causes isolated anemia rather than the broad dysplasia seen in MDS.

Infections

When your body fights off an infection, your bone marrow can become “reactive,” temporarily altering blood cell production ^[8].

• Viral Infections: Viruses such as HIV, Hepatitis B or C, Epstein-Barr virus (EBV), and cytomegalovirus (CMV) can suppress the bone marrow ^[8]. Parvovirus B19 specifically targets red blood cell production, severely lowering your red cell count. Even COVID-19 can occasionally cause temporary cytopenias ^[9]. Your hematologist will order specific viral tests based on your clinical picture and exposure history rather than running a universal panel.

Autoimmune and Inflammatory Disorders

Conditions where your immune system attacks your own body can also affect your bone marrow:

• Autoimmune Diseases: Disorders like lupus (SLE) or rheumatoid arthritis can cause your immune system to destroy healthy blood cells or suppress their production ^[10].
• VEXAS Syndrome: This is a rare inflammatory disorder caused by an acquired (somatic) mutation in the UBA1 gene ^[11]. It usually affects older men (though not exclusively) and causes unexplained fevers, systemic symptoms (like severe joint pain or skin rashes), and vacuoles (bubble-like spaces) in marrow cells ^[11]. Because vacuoles can occur in other conditions, diagnosis requires matching the clinical inflammatory pattern with the specific UBA1 mutation ^[11].

Aplastic Anemia and Other Marrow Disorders

Sometimes the challenge lies in distinguishing MDS from other rare bone marrow failure diseases.

• Aplastic Anemia vs. Hypoplastic MDS: Typical MDS often features a hypercellular (more crowded than expected for your age) bone marrow ^[12]. In contrast, aplastic anemia generally features a hypocellular (less cellular or “emptier”) marrow ^[12]. However, a rare subtype called hypoplastic MDS also has a hypocellular marrow ^[13]. Distinguishing them is complex and requires experts to integrate your age-adjusted cellularity, blast percentage, genetics, and clinical history ^[13].
• Paroxysmal Nocturnal Hemoglobinuria (PNH): This rare, acquired blood disorder can cause red blood cell destruction and blood clots, and it sometimes overlaps with aplastic anemia or MDS ^[14].

How Doctors Tell the Difference

Because low counts and dysplasia are not specific to MDS, a diagnosis requires integrating multiple tests over time ^[15]:

• Detailed History and Blood Tests: Your doctor will evaluate your diet, prior surgeries, medications, and specific lab tests (like kidney/liver function, vitamins, iron studies, and viral markers).
• Advanced Bone Marrow Testing: Doctors rely on cytogenetics (testing the chromosomes inside the cells) and flow cytometry (a laser-based test to analyze cell features) to look for abnormalities ^{[16] [17]}. While finding a specific abnormality can strongly support an MDS diagnosis, a normal result does not completely rule out MDS ^[16].
• Molecular Profiling (DNA Sequencing): Finding a genetic mutation in your blood cells does not automatically confirm MDS. Some older adults develop mutations without diagnostic cytopenias—a condition called Clonal Hematopoiesis of Indeterminate Potential (CHIP) ^[18]. While CHIP is not MDS, it is not harmless, as it increases the future risk of blood cancers and cardiovascular disease ^[18]. If you have low blood counts and a mutation but do not meet the full criteria for MDS, doctors may call this Clonal Cytopenia of Undetermined Significance (CCUS) ^[18]. Ultimately, no single genetic or visual finding provides a simple “yes or no” answer; diagnosis requires careful review by an experienced hematopathologist ^[16].