Leukemic Transformation of Longstanding Essential Thrombocythemia

Case Report

Ann Hematol Onco. 2023; 10(4): 1433.

Leukemic Transformation of Longstanding Essential Thrombocythemia

Weir SJ¹*; Talari MP²; Nakhoul I³

¹Medical Student, Edward via College of Osteopathic Medicine, USA

²Department of Internal Medicine, Johnston Memorial Hospital, USA

³Department of Hematology and Oncology, Ballad Health Cancer Center, USA

*Corresponding author: Seth Weir Medical Student, Edward via College of Osteopathic Medicine, USA. Email: [email protected]

Received: June 26, 2023 Accepted: July 22, 2023 Published: July 29, 2023


Acute Myeloid Leukemia (AML) represents only 1% of all cancers, despite being the most frequent type of leukemia [1]. Multiple genetic pathways are associated with AML, causing various changes in genetic transcription, apoptosis, chromatin remodeling, and protein levels. One such pathway, the JAK-STAT pathway, governs cellular proliferation, differentiation, and apoptosis, and is linked to both AML and myeloproliferative neoplasms due to mutations [2]. The JAK V617F mutation is the most common mutation in this pathway, occurring in about 50% of Essential Thrombocythemia (ET) patients, as described in this report [2]. While rare, transformation of Essential Thrombocythemia (ET) to AML occurs in 1-4% of cases [3]. This report presents a case of AML in a 76-year-old male with a medical history of ET. Following an abnormal peripheral blood smear, bone marrow biopsy confirmed the diagnosis. The current report aims to emphasize the significance of regular screening and monitoring for patients with long-standing Essential Thrombocythemia (ET), especially those under suppressive therapy. The transformation of ET to acute leukemia is associated with an unfavorable prognosis, underscoring the importance of early diagnosis. Therefore, this case serves to draw attention to the criticality of timely intervention through routine follow-up to achieve optimal outcomes for patients with ET.

Keywords: Acute Myeloid Leukemia; AML; ET; Essential thrombocythemia; Leukemic transformation

Case Presentation

This case describes a 76-year-old male with a past medical history of hypertension, Gastroesophageal Reflux Disease (GERD), vitamin B12 deficiency, and Essential Thrombocythemia (ET) for the past 19 years. The patient had an initial platelet count of 1143 K/uL and was tested for the JAK V617F mutation 8 years ago, when it was detected. The patient's ET was managed with Hydrea 500 mg BID for 13 years with a target platelet count of less than 600,000 K/uL. However, the patient had to decrease his Hydrea to 500 mg QD due to worsening anemia. On presentation to the oncology clinic, the patient's CBC showed low white blood cell counts (2.4 K/uL), low hemoglobin (8.7 g/dL), low hematocrit (26.3%), and a platelet count of 267 K/uL. The patient was found to have blast of 0.34 K/uL on manual differential. A Peripheral Blood Smear (PBS) was performed to further workup the patient's anemia, and it showed 5% blast-like cells, marked anisopoikilocytosis with dacrocytes and schistocytes, and no rouleaux formations.

Bone marrow biopsy was done, and it demonstrated increased blast-like cells (32.6%) with the cells of interest being 2-3x the size of normal red blood cells. Cytoplasmic granules were noted, and the cells were CD34 positive in 25-30%, with those that were positive expressing myeloperoxidase. The cells were negative for CD79a, cCD3, and TdT. Cells were TP 53 positive, IDH1 negative, IDH2 negative, and NPM1 negative. FLT3 mutation was not detected. Chromosomal analysis indicated an abnormal karyotype of: 62~65<3n>,XYY,-3,-5,add l(6)(q21),-7,+8,-12,-13,-15,-16,-17,-17,+18, add (19) (q13.3),-20,+22,+mar[cp17]/46,XY [3]. The bone marrow biopsy result was consistent with transformation of ET into Acute Myeloid Leukemia (AML) in Figure 1-4.