Symptom Finder - Polycythemia
POLYCYTHEMIA
Pathophysiology will help to form a list of diagnostic possibilities in a case of polycythemia. First, it is important to exclude those cases of polycythemia that are due to a reduced plasma volume such as dehydration, diarrhea, and Gaisböck syndrome in which the actual red cell mass is normal. Next, separate those cases of polycythemia that are caused by an outside stimulus to the bone marrow. This involves two groups: those with anoxia as the stimulus and those with the hormone erythropoietin as the stimulus.
The anoxic group includes pulmonary emphysema, alveolar hypoventilation, and cyanotic congenital heart disease. The group with erythropoietin as the stimulus includes pheochromocytoma, Cushing disease, hydronephrosis, renal cell carcinoma, renal cyst, cerebellar hemangioblastoma, and hematoma. Finally, we are left with the form of polycythemia that has no outside stimulus for red cell production: polycythemia vera. This is most likely a neoplastic disorder, and, in fact, it has been termed a “myeloproliferative” syndrome. In this disorder, there is also leukocytosis and thrombocytosis, which are distinguishing features.
Approach to the Diagnosis
Blood volume studies, serum and urine osmolality studies, and electrolyte assessment will help differentiate relative or spurious forms of polycythemia. Arterial blood gas analysis will distinguish those cases associated with anoxia such as pulmonary emphysema and cyanotic heart disease. Determining the blood erythropoietin will help to differentiate cases where the erythropoietin is the stimulus such as renal carcinoma and pulmonary emphysema. The erythropoietin is low in polycythemia vera.
Other Useful Tests
1. CBC (polycythemia)
2. Platelet count (polycythemia vera)
3. Chemistry panel (renal disease, heart disease)
4. IVP (hypernephroma)
5. CT scan of the abdomen (hypernephroma)
6. Chest x-ray (pulmonary emphysema)
7. Pulmonary function studies (pulmonary fibrosis or emphysema)
8. Cardiac catheterization (congenital heart disease)
9. Pulmonary consult
10. Hematology consult
11. Bone marrow examination (myeloproliferative disorder)
Pathophysiology will help to form a list of diagnostic possibilities in a case of polycythemia. First, it is important to exclude those cases of polycythemia that are due to a reduced plasma volume such as dehydration, diarrhea, and Gaisböck syndrome in which the actual red cell mass is normal. Next, separate those cases of polycythemia that are caused by an outside stimulus to the bone marrow. This involves two groups: those with anoxia as the stimulus and those with the hormone erythropoietin as the stimulus.
The anoxic group includes pulmonary emphysema, alveolar hypoventilation, and cyanotic congenital heart disease. The group with erythropoietin as the stimulus includes pheochromocytoma, Cushing disease, hydronephrosis, renal cell carcinoma, renal cyst, cerebellar hemangioblastoma, and hematoma. Finally, we are left with the form of polycythemia that has no outside stimulus for red cell production: polycythemia vera. This is most likely a neoplastic disorder, and, in fact, it has been termed a “myeloproliferative” syndrome. In this disorder, there is also leukocytosis and thrombocytosis, which are distinguishing features.
Approach to the Diagnosis
Blood volume studies, serum and urine osmolality studies, and electrolyte assessment will help differentiate relative or spurious forms of polycythemia. Arterial blood gas analysis will distinguish those cases associated with anoxia such as pulmonary emphysema and cyanotic heart disease. Determining the blood erythropoietin will help to differentiate cases where the erythropoietin is the stimulus such as renal carcinoma and pulmonary emphysema. The erythropoietin is low in polycythemia vera.
Other Useful Tests
1. CBC (polycythemia)
2. Platelet count (polycythemia vera)
3. Chemistry panel (renal disease, heart disease)
4. IVP (hypernephroma)
5. CT scan of the abdomen (hypernephroma)
6. Chest x-ray (pulmonary emphysema)
7. Pulmonary function studies (pulmonary fibrosis or emphysema)
8. Cardiac catheterization (congenital heart disease)
9. Pulmonary consult
10. Hematology consult
11. Bone marrow examination (myeloproliferative disorder)