Extramedullary relapse of acute myeloid leukemia in a surgical wound

Abstract

A 52-year-old woman diagnosed with Graves' thyroiditis 2 years previously was evaluated for surgical management due to medical non-compliance and a reluctance to pursue radioiodine ablation. A routine complete blood count (CBC) was within normal limits. There was no history of head or neck irradiation, and her family history was unknown, as she was adopted. She denied any bleeding or bruising difficulties. Thyroid ultrasound revealed a slightly heterogeneous gland without discrete nodules. There was no abnormal cervical adenopathy. Total thyroidectomy was performed, with some difficulty achieving hemostasis after the specimen was removed from the field. She was discharged on the first postoperative day, but had to be seen in the office on postoperative day 2 because of a large ecchymotic area around the incision. The wound edges had also separated. Pathology findings were consistent with Graves' disease without evidence of malignancy. On postoperative day 4 she was readmitted to the hospital for ongoing bleeding and pain at her thyroid incision. On admission, her platelet count was 79 6 10 9 /L and her white blood cell (WBC) count was 20.0 6 10 9 /L. Her platelet count continued to decrease, and the Hematology and Oncology service was consulted. Peripheral smear showed 35% blasts. Based on this finding, an acute leukemia was suspected. A bone marrow biopsy performed on postoperative day 6 demonstrated 70% cellularity with 82% blasts.Immunophenotyping by flow cytometry showed that blasts were positive for myeloperoxidase (MPO), CD33, CD15, CD36, CD64, and CD4 with minimal expression of CD14. Cytogenetic studies showed a karyotype 46,XX,i(8)(q10),der(22)t(8;22)(q13;q13) in 19 out of 20 metaphases. Based on the World Health Organization WHO classification of tumours of haematopoietic and lymphoid tissues, the patient was diagnosed with acute monoblastic leukemia. Induction chemotherapy was initiated with daunorobucin (60 mg/m 2 /day, days 1-3) and cytarabine (100 mg/ m 2 /day, days 1-7). On day 14 after induction chemotherapy, her bone marrow biopsy showed a cellularity of 15% with 2% blasts. Two weeks later, the patient was discharged in a stable condition. However, 2 weeks after discharge, she presented with an enlarging neck mass. On physical examination, she had developed an infiltrating irregular mass in the subcutaneous tissue beneath the thyroidectomy incision, which was painful and tender to palpation (Figure 1, upper). Ultrasound examination showed it to be very heterogeneous and hypervascular.A fine needle aspiration biopsy of the neck mass was performed. Morphologically, the cells resembled leukemic blasts. Immunohistochemistry showed positivity for CD45, CD15, CD4, and MPO. A computed tomography (CT) scan demonstrated a large anterior neck mass within the subcutaneous tissues, extending into the paratracheal space bilaterally without compression of the airways (Figure 1, lower). Prior to the procedure, her CBC was within normal limits, but in 48 h her white blood cell (WBC) count increased to 10.7 6 10 9...

Symptoms, Diagnosis, Mechanism, and Treatment of Extramedullary Relapse in Acute Myeloid Leukemia

“…EMR can occur in any part of the body, where CNS, skin, and soft tissues are the most common sites of EMR in AML patients [6], known as "refuge"; when EMR involves multiple organs, it can show diffuse multiorgan involvement. In some case reports, EMR including ocular [1,7], cardiac [8], breast [9], thyroid [10], ovarian [11,12], and bone [13].…”