- This 35 Year Old White Woman Initially Presented With Thrombocytosis Platelet Count 1200 X 109 L Discovered On Routin 1 (221.33 KiB) Viewed 30 times
- This 35 Year Old White Woman Initially Presented With Thrombocytosis Platelet Count 1200 X 109 L Discovered On Routin 2 (28.11 KiB) Viewed 30 times
This 35-year-old white woman initially presented with thrombocytosis (platelet count, 1200 x 109/L) discovered on routine physical examination. Her WBC and Hgb values were normal. The history was unremarkable except for occasional epistaxis and minor bruising. She was advised to have a routine follow-up examination and CBC every 3 months and, despite a continually elevated platelet count, remained asymptomatic for 3 years. At that time, she was seen by her physician with complaints of dizziness, visual disturbances, and erythromelalgia. She had also had recent dental surgery and experienced a major perioperative bleeding episode. Mild splenomegaly was noted. Her platelet count was 2500 x 10°/L. Other laboratory values were as follows: WBC count: 18.5 x 105/L; Hct: 28.5%; prolonged bleeding time; reduced platelet adhesion; and defective platelet aggregation with epinephrine. Bone marrow biopsy demonstrated megakaryocytic hyperplasia with massive platelet clumping. Erythroid and myeloid hyperplasia, as well as a mild increase in reticulin content, were also observed. Plateletpheresis was performed to rapidly reduce the marked thrombocytosis. The patient was treated with the myelosuppressive agent hydroxyurea in dosag varying from 1 g/day to 500 mg five times per week, depending on the platelet counts. The bleeding and vaso-occlusive symptoms were resolved, and coagulation abnormalities were corrected. Close follow-up is necessary for this patient to ensure a continued beneficial clinical and laboratory response. COMMENT This case highlights the common findings in essential thrombocythemia (ET); namely, marked increased platelet counts, thrombohemorrhagic events, splenomegaly, and bone marrow megakaryocytic hyperplasia. Although this is primarily a disease of upper-middle-age (50 to 70 years) a second population of younger, predominantly female patients exists. Two-thirds of patients are asymptomatic, as was this patient initially. With the advent of automated cell counte that routinely generate platelet counts, asymptomatic patients are being discovered more frequently. The erythromelalgia noted in this patient represents one of the most characteristic vaso-occlusive manifestations. Prolonged bleeding after trauma or surgery i a common finding related to platelet dysfunction. In an asymptomatic young patient with platelet counts below 1000 to 1500 x 10°/L, it is advisable to withhold myelosuppressive therapy, because these patien do well for many years untreated. When a patient requiring surgery presents with markedly increased platelet count and hemorrhagic complications, plateletpheresis will lower the platelet count dramatically. In addition, myelosuppression is necessary to control the hyperproliferative process. Causes of reactive thrombocytosis, such as iron deficiency anemia, malignancy, inflammatory disorders, splenectomy, and so on, are generally easy to exclude based on the clinical and hematologic features of the individual patient. To reliably exclude the other chronic MPDs, the PVSG guidelines should be followed. T distinguish a patient with ET from an iron-deficient PV patient, serum iron, TIBC, ferritin, and bone marrow iron stains are usually sufficient. A trial of oral iron i rarely required. In patients with anemia, splenomegaly, thrombocytosis, and leukocytosis, the presence of the Ph chromosome is unequivocal evidence of CML The outlook for long-term survival in ET is encouraging as long as appropriate measures are taken to minimize thrombohemorrhagic complications. Many patients can tolerate markedly increased platelet counts for years without any complications. The introduction of plateletpheresis has allowed dramatic response in life-threatening or urgent surgical situations. In addition, hydroxyurea has proved to be an effective chemotherapeutic agent. MLT 220: Myeloproliferative Neoplasms Homework Page 11 of
QUESTIONS 1. Why did this patient experience a major perioperative bleeding episode when her platelet count was 2500 x 109/L? 2. Erythromelalgia can progress into what clinical manifestation? 3. What is the reason for the megakaryocytic hyperplasia seen in the bone marrow biopsy?