The Clinical Presentations Of The Various Forms Of Myeloproliferative Syndromes
A General Overview
The disease is seen generally above the age of 20 years and the incidence increases with age. Males are affected more. The onset is gradual and the main symptoms are caused by hyperviscosity, hypervolemia and hypermetabolism. Initial symptoms are vague such as headache, dizziness, tinnitus, weakness, lassitude, fatigue, angina, visual disturbances such as diminution of vision, recurrent venous thrombosis and hemorrhages. Hyperuricemia may lead to secondary gout. Severe pruritus, especially after a hot bath, is a common symptom.
Physical examination reveals congestion and plethoric appearance of the face with congested conjunctiva. The spleen is palpable (5-10cm) in 75% cases. Fundi reveal congestion of the discs, engorged veins and hemorrhages. The cerebral, retinal, cardiac or peripheral vessels may be the seat of vascular occlusions. Hemorrhage from the gastrointestinal tract, urinary tract and uterus may occur. Peptic ulcer is more commonly found in polycythemic subjects. Many develop hypertension (Gaisboch’s syndrome) and some manifest easy bruising tendency.
Examination of blood reveals the increase in all formed elements. Erythrocyte sedimentation rate is diminished. The bone marrow is hypercellular with normoblastic hyperplasia and prominence of megakaryocytes. Leukocyte alkaline phosphatase is high. There is increase in transcobalamin and, therefore, serum B12 levels and B12-binding capacity are elevated. The red cell volume can be accurately estimate isotopically using 51Cr labeled erythrocytes.
The Various Forms Of Polycythemia
In this type, only erythrocytes are increased and there is no splenomegaly. The clinical features are those of the underlying disorder. Though, the complications of polycythemia are not usually encountered, the microcirculation may be impaired when the hematocrit rises above 60%. Correction of the primary disorders relieves this form of polycythemia.
Stress Polycythemia (Spurious polycythemia, Gaisbock’s Syndrome)
This is rare condition seen at times in persons who undergo severe mental stress. The erythropoietin levels are normal. The polycythemia is only relative. Mechanism of production is unknown. Often, the blood pressure is elevated (“Gaisbock’s syndrome”). Removal of tension and psychological adaption brings about relief.
Essential Thrombocythemia (Megakaryocytic Myelosis)
This is the rarest among the myeloproliferative syndromes, seen in older subjects presenting with thombotic and hemorrhagic manifestations. The platelet count may exceed 1000 X 109/liter (1000,000/cmm) and megakaryocytes are increased in the marrow. It is a neoplastic process occurring equally in both sexes. Spleen may be enlarged in 60% of the cases. Clinical features combine hemorrhagic and thrombotic lesions.
Polycythemia In Blood Specimen
Hematology: The main abnormality is a gross elevation of the platelet count, often above 1000,000/cmm. Though, the count is high, platelet function may be defective.
Diagnosis: The condition should be suspected when there are hemorrhagic and thrombotic tendencies, especially gangrene of the fingers or toes, associated with splenomegaly, and elevated platelet counts.
Course and prognosis: The course is benign, punctuated with complications. Some cases end up as polycythemia vera, others as chronic myeloid leukemia or myelofibrosis. Some cases run true to type for over 10 years.
Treatment: Busulphan and 32P may be employed as for polycythemia vera. Removal of platelets by a cell separator has been attempted to tide over an emergency, when platelet counts are very high. Aspirin 150 mg orally daily may help in preventing thrombotic tendencies.
© 2014 Funom Theophilus Makama