7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria

ABIM Internal Medicine Exam

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1 Chapter 0: The ABIM Exam, Blueprint & Study Strategy

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2 Chapter 1: Cardiovascular Disease (14% of Exam)

1.1 Ischemic Heart Disease & Acute Coronary Syndromes 1.2 Antithrombotic Therapy, Secondary Prevention & Mechanical Complications of MI 1.3 Atrial Fibrillation, Atrial Flutter & Stroke Prevention 1.4 Supraventricular Tachycardias, Ventricular Arrhythmias & Bradycardias 1.5 Heart Failure: Classification, Staging & Guideline-Directed Medical Therapy 1.6 Device Therapy, HFpEF & the Cardiomyopathies 1.7 Valvular Heart Disease & Endocarditis Prophylaxis 1.8 Pericardial Disease & Acute Aortic Syndromes 1.9 Hypertension: Classification, Diagnosis & Secondary Causes 1.10 Hypertensive Crises & Dyslipidemia 1.11 Adult Congenital Heart Disease & Coarctation of the Aorta 1.12 Syncope: Reflex, Orthostatic & Cardiac Causes 1.13 Cardiac Physical Examination, Murmurs & Antithrombotic Selection

3 Chapter 2: Endocrinology, Diabetes & Metabolism (9% of Exam)

2.1 Diabetes Mellitus: Diagnosis, Glycemic Targets & Pharmacotherapy 2.2 Insulin Therapy, Hyperglycemic Emergencies & Chronic Complications 2.3 Thyroid Function Testing & Hypothyroidism 2.4 Thyrotoxicosis, Thyroid Storm & Thyroid Nodules 2.5 Adrenal & Pituitary Disorders 2.6 Hypercalcemia, Hypocalcemia & Disorders of Mineral Metabolism 2.7 Osteoporosis & Paget Disease of Bone 2.8 Ovarian, Testicular & Reproductive Endocrine Disorders 2.9 Hypoglycemia, Endocrine Tumors, Polyglandular Syndromes & Severe Hypertriglyceridemia

4 Chapter 3: Gastroenterology & Hepatology (9% of Exam)

3.1 Esophageal Disease 3.2 Stomach & Duodenal Disease and Gastrointestinal Hemorrhage 3.3 Inflammatory Bowel Disease 3.4 Celiac Disease & Irritable Bowel Syndrome 3.5 Diverticular Disease & Colorectal Cancer Screening 3.6 Viral Hepatitis, Steatotic & Alcohol-Associated Liver Disease 3.7 Cirrhosis & the Complications of Portal Hypertension 3.8 Acute Pancreatitis 3.9 Chronic Pancreatitis & Biliary Tract Disease 3.10 Inherited, Autoimmune & Drug-Induced Liver Disease 3.11 Small Intestinal Disease, Ischemia & Gastrointestinal Complications of HIV

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6.1 Rheumatoid Arthritis: Diagnosis & Systemic Manifestations 6.2 Antirheumatic Pharmacotherapy & the Spondyloarthropathies 6.3 Gout: Pathophysiology & Acute Management 6.4 Urate-Lowering Therapy & Calcium Pyrophosphate Deposition Disease 6.5 Osteoarthritis 6.6 Systemic Lupus Erythematosus 6.7 Systemic Sclerosis, Sjogren Syndrome & Inflammatory Myopathies 6.8 The Vasculitides 6.9 Regional Musculoskeletal Syndromes, Back Pain & Sports Injuries 6.10 Other Primary Rheumatic Disorders & Mixed Connective Tissue Disease 6.11 Osteonecrosis & Metabolic Bone Disease

8 Chapter 7: Hematology (6% of Exam)

7.1 Approach to Anemia & the Microcytic Anemias 7.2 Macrocytic, Normocytic & Hemolytic Anemias 7.3 Hemoglobinopathies, Thalassemias & Paroxysmal Nocturnal Hemoglobinuria 7.4 Platelet Disorders, Thrombocytopenia & the Bleeding Patient 7.5 Coagulation Factor Disorders, Thrombophilia & Anticoagulant Reversal 7.6 Acute Leukemias, Chronic Leukemias & Myeloproliferative Neoplasms 7.7 Lymphomas & Plasma Cell Disorders 7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria 7.9 Transfusion Medicine & Late Complications of Transplantation

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9.1 Acute Kidney Injury: Staging, Etiology & Urine Microscopy 9.2 Glomerular Disorders & Nephrotic Syndrome 9.3 Nephritic Syndromes, RPGN & Indications for Renal Replacement Therapy 9.4 Chronic Kidney Disease: Staging & Progression Retardation 9.5 Complications of Chronic Kidney Disease: Anemia, CKD-MBD & Acidosis 9.6 Hyponatremia, Hypernatremia & Water Balance 9.7 Potassium Disorders & Systematic Acid-Base Analysis 9.8 Renal Tubular Acidosis & Nephrolithiasis 9.9 Prostate Disorders, Urinary Incontinence & Other Urologic Conditions 9.10 Cystic Kidney Disease, Obstructive Uropathy, Tubulointerstitial Disease & Hematuria

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10.1 Acute Ischemic Stroke: Syndromes & Reperfusion 10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke 10.3 Headache & Facial Pain 10.4 Seizures, Epilepsy & Movement Disorders 10.5 Multiple Sclerosis & Neuromuscular Junction Disorders 10.6 Motor Neuron Disease & Acute Peripheral Neuropathy 10.7 Cranial Neuropathies & Neuro-Ophthalmology 10.8 Peripheral Neuropathies, CNS Tumors & Other Neurologic Disorders

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12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses 12.2 Acne, Rosacea & Cutaneous Infections 12.3 Herpes Zoster & Autoimmune Blistering Diseases 12.4 Nodules, Tumors & Cutaneous Oncology 12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions 12.6 Pigment Disorders, Alopecia, Nail Disease & Photosensitivity 12.7 Vascular Dermatoses, Environmental Injury & Cutaneous Signs of Systemic Disease

14 Chapter 13: Obstetrics & Gynecology / Women's Health (3% of Exam)

13.1 Contraception, Preconception Care & Teratogenicity 13.2 Hypertensive Disorders of Pregnancy & Gestational Diabetes 13.3 Thyroid Disease & Venous Thromboembolism in Pregnancy 13.4 Menopause & Menopausal Hormone Therapy 13.5 Abnormal Uterine Bleeding, Endometrial Disease & Gynecologic Cancer Screening 13.6 Breast Disorders & Diseases of the Vulva and Vagina 13.7 Menstrual Disorders, Fibroids, Endometriosis & Early Pregnancy Complications

15 Chapter 14: Geriatric Syndromes (3% of Exam)

14.1 Comprehensive Geriatric Assessment & Frailty 14.2 Falls, Gait Assessment & Polypharmacy 14.3 Urinary Incontinence & Pressure Injuries in Older Adults 14.4 Mild Cognitive Impairment, Dementia & Its Subtypes 14.5 Delirium & the Pharmacotherapy of Cognitive Disorders 14.6 Palliative Care, Hospice & Advance Care Planning 14.7 Chronic Wounds, Nutrition, Swallowing, Constipation & Hip Fracture 14.8 Sensory Impairment, Dizziness, Elder Mistreatment & Care Settings

16 Chapter 15: Allergy & Immunology (2% of Exam)

15.1 Anaphylaxis: Recognition & Emergency Management 15.2 Urticaria & Angioedema 15.3 Drug Allergy, Desensitization & Adult Immunodeficiency 15.4 Food Allergy, Insect Venom Hypersensitivity, Serum Sickness & Contrast Reactions 15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders

17 Chapter 16: Preventive Medicine, Immunization & Clinical Epidemiology

16.1 The USPSTF Framework & Evidence-Based Cancer Screening 16.2 Cardiovascular & Metabolic Screening and Primary Prevention 16.3 Adult Immunization & Vaccines in Special Populations 16.4 Clinical Epidemiology, Biostatistics & Study Design

18 Chapter 17: Miscellaneous - Ethics, Patient Safety & Quality Improvement (2% of Exam)

17.1 Principles of Bioethics & Decisional Capacity 17.2 Informed Consent, Treatment Refusal & Special Scenarios 17.3 Surrogate Decision-Making, Advance Directives & Confidentiality 17.4 Patient Safety Science, Medical Error & Diagnostic Reasoning 17.5 Quality Improvement Methods, Health Disparities & Health Equity

19 Chapter 18: Perioperative Medicine & Medical Consultation

18.1 Preoperative Cardiovascular Risk Assessment 18.2 Preoperative Pulmonary Risk & Perioperative Medication Management 18.3 Perioperative Anticoagulation, Bridging & Postoperative Complications

20 Chapter 19: Ophthalmology (1% of Exam)

19.1 The Acute Red Eye & Ophthalmic Emergencies 19.2 Painless Vision Loss & Chronic Ophthalmic Disease 19.3 Uveitis, Scleritis & Orbital Disease

21 Chapter 20: Otolaryngology & Dental Medicine (1% of Exam)

20.1 Dizziness, Vertigo & Epistaxis 20.2 Ear Disorders, Hearing Loss & Upper Respiratory Infections 20.3 Oral Cavity, Salivary Gland, Laryngeal & Taste and Smell Disorders

7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria

Key Takeaways Explain This Topic AI

Myelodysplastic syndrome, myeloproliferative disorders, leukocyte disorders and porphyria are four separate named blueprint subsections.

Myelodysplastic syndrome should be suspected in an older adult with unexplained macrocytic anemia and dysplastic changes after B12, folate, thyroid and copper deficiency are excluded.

Polycythemia vera is suggested by an elevated hemoglobin with a suppressed erythropoietin level and is confirmed by JAK2 mutation testing.

Low-dose aspirin plus phlebotomy to a hematocrit below 45% reduces thrombosis in polycythemia vera.

Acute intermittent porphyria causes recurrent abdominal pain with neuropsychiatric features and normal imaging, and is confirmed by elevated urinary porphobilinogen during an attack.

Last updated: August 2026

1. Myelodysplastic Syndrome

A clonal stem cell disorder producing ineffective hematopoiesis : a hypercellular marrow with peripheral cytopenias , dysplastic morphology, and a variable risk of transformation to acute myeloid leukemia. It is predominantly a disease of older adults.

When to suspect it: an older patient with unexplained macrocytic anemia and a low reticulocyte count . The reticulocyte response is the discriminator — the marrow is cellular but the cells die before release.

Before diagnosing myelodysplastic syndrome, exclude the reversible mimics , and this exclusion list is what exam items test:

Mimic Test
Vitamin B12 deficiency B12, methylmalonic acid
Folate deficiency Folate, homocysteine
Copper deficiency Serum copper and ceruloplasmin — think bariatric surgery, zinc excess
Hypothyroidism Thyroid-stimulating hormone
HIV HIV testing
Alcohol and drugs History; methotrexate, hydroxyurea, azathioprine, linezolid

Copper deficiency is the classic overlooked cause , producing a myelodysplasia-like marrow picture that is fully reversible with repletion, together with a myeloneuropathy that mimics B12 deficiency. Ask about bariatric surgery and zinc supplementation, including excessive denture adhesive use.

Diagnosis requires bone marrow aspiration and biopsy with cytogenetics. Peripheral clues include hypolobated hypogranular neutrophils (pseudo-Pelger-Huet cells) and dimorphic red cells.

Prognosis is stratified by the Revised International Prognostic Scoring System using blast percentage, cytogenetics and depth of cytopenias. Isolated deletion 5q is a favorable subtype with macrocytic anemia and preserved or elevated platelets that responds to lenalidomide .

Management ranges from transfusion support and erythropoiesis-stimulating agents in lower-risk disease to hypomethylating agents in higher-risk disease. Allogeneic hematopoietic cell transplantation is the only curative therapy , limited by age and comorbidity.

2. Myeloproliferative Neoplasms

Clonal expansion producing too many mature cells, in contrast to the ineffective production of myelodysplasia.

Neoplasm Dominant lineage Driver mutations
Polycythemia vera Red cells JAK2 V617F in over 95%
Essential thrombocythemia Platelets JAK2, CALR, MPL
Primary myelofibrosis Fibrosis, cytopenias JAK2, CALR, MPL
Chronic myeloid leukemia Granulocytes BCR-ABL1
Polycythemia vera

Diagnostic approach: an elevated hemoglobin or hematocrit with a suppressed erythropoietin level points to a primary (autonomous) process; a raised erythropoietin points to a secondary cause such as hypoxemia, obstructive sleep apnea, high altitude, smoking, testosterone therapy, or an erythropoietin-secreting tumor. Confirm with JAK2 V617F , and test JAK2 exon 12 if V617F is negative.

Clinical clues: aquagenic pruritus (itching after a hot shower), erythromelalgia, plethora, splenomegaly, and thrombosis at unusual sites — Budd-Chiari syndrome and splanchnic vein thrombosis should always prompt myeloproliferative evaluation.

Treatment: phlebotomy to a hematocrit below 45% plus low-dose aspirin , with cytoreduction using hydroxyurea or ruxolitinib in high-risk patients (age over 60 or prior thrombosis). The hematocrit target below 45% is supported by randomized data showing fewer cardiovascular deaths and thromboses.

Essential thrombocythemia and primary myelofibrosis

Essential thrombocythemia must be separated from reactive thrombocytosis — infection, inflammation, iron deficiency, post-splenectomy and malignancy are far more common causes of a high platelet count. Paradoxically, extreme thrombocytosis above roughly 1,000,000 per microliter can cause bleeding through acquired von Willebrand syndrome.

Primary myelofibrosis presents with marked splenomegaly, constitutional symptoms, a leukoerythroblastic smear with teardrop cells (dacrocytes) , and a dry tap on marrow aspiration. JAK inhibition reduces spleen size and symptoms; transplantation is the only cure.

3. Leukocyte Disorders

The blueprint lists leukopenia, leukocytosis and eosinophilia under leukocyte disorders.

Neutropenia: distinguish benign ethnic neutropenia (a normal variant, notably in people of African ancestry, without infection risk) from drug-induced, autoimmune and marrow-failure causes.

Leukocytosis: a leukemoid reaction (usually under 50,000 with a left shift and high leukocyte alkaline phosphatase) versus chronic myeloid leukemia (basophilia, low leukocyte alkaline phosphatase, BCR-ABL1 positive).

Eosinophilia: the practical mnemonic is NAACP — Neoplasm, Allergy/Asthma, Adrenal insufficiency, Connective tissue disease, Parasites. Strongyloides must be excluded before corticosteroids because of hyperinfection risk. Marked persistent eosinophilia with organ damage defines hypereosinophilic syndrome and requires evaluation for a clonal disorder.

4. Porphyria

A separately named blueprint subsection. The porphyrias are disorders of heme biosynthesis, and they are tested because they masquerade as common problems.

Acute intermittent porphyria

The classic acute hepatic porphyria. Presentation:

Severe, poorly localized abdominal pain that is out of proportion to a benign abdominal examination , with normal imaging and often normal laboratory studies apart from hyponatremia

Autonomic features — tachycardia, hypertension, vomiting, constipation

Neuropsychiatric features — motor neuropathy (which can progress to quadriparesis), seizures, anxiety, psychosis

Reddish or port-wine urine that darkens on standing in light
No cutaneous photosensitivity — a key discriminator

Attacks are precipitated by cytochrome P450-inducing drugs (barbiturates, sulfonamides, rifampin, phenytoin, carbamazepine, progesterone), fasting or crash dieting, alcohol, infection, surgery, and the luteal phase of the menstrual cycle. A young woman with recurrent unexplained abdominal pain who has had a negative laparotomy is the archetypal vignette.

Diagnosis: urinary porphobilinogen and delta-aminolevulinic acid measured on a spot sample obtained during the attack . Testing between attacks may be normal.

Treatment: stop the offending drug, provide intravenous glucose and, for severe attacks, intravenous hemin , which suppresses ALA synthase and aborts the attack. Pain is treated with opioids; many common analgesics and sedatives are unsafe, so a porphyria-safe drug list must be consulted.

Porphyria cutanea tarda

The most common porphyria overall, and clinically the opposite of the acute hepatic porphyrias: cutaneous, not neurovisceral .

Painless blistering and skin fragility on sun-exposed skin , especially the dorsa of the hands
Hypertrichosis, hyperpigmentation, scarring and milia
No abdominal pain and no neuropathy

It is strongly associated with hepatitis C, HIV, alcohol, estrogen therapy, smoking and iron overload including HFE mutations — so a new diagnosis obliges testing for hepatitis C, HIV and iron studies. Urinary uroporphyrins are elevated. Treatment is repeated phlebotomy or low-dose hydroxychloroquine , plus sun protection and removal of the precipitant. Curing hepatitis C frequently resolves it.

Erythropoietic protoporphyria

Presents in childhood with immediate painful burning of sun-exposed skin without blistering — a distinctive history because the pain begins within minutes and the skin often looks normal, leading to years of misdiagnosis. It can cause protoporphyric liver disease.

5. Aplastic Anemia

Enumerated under hypoproliferative anemia and worth contrasting with myelodysplasia. Pancytopenia with a hypocellular marrow and no dysplasia or fibrosis , reflecting immune-mediated destruction of hematopoietic stem cells.

Causes include idiopathic autoimmune disease, drugs (chloramphenicol, carbamazepine, gold, sulfonamides), viruses (parvovirus B19 in the immunocompromised, seronegative hepatitis, Epstein-Barr virus), radiation, benzene, and inherited marrow failure syndromes such as Fanconi anemia and telomere biology disorders. Paroxysmal nocturnal hemoglobinuria clones coexist in a substantial minority , and flow cytometry should be sent.

Treatment: allogeneic transplantation for younger patients with a matched donor; immunosuppression with antithymocyte globulin and cyclosporine, increasingly with eltrombopag, for others.

The contrast that generates exam points: aplastic anemia gives a hypocellular marrow without dysplasia; myelodysplastic syndrome gives a hypercellular marrow with dysplasia — although a hypocellular variant of myelodysplasia exists and blurs the distinction.