Extramedullary Relapse In Acute Leukemia Following Allogeneic Hematopoietic Stem Cell Transplantation: Incidence, Risk Factors And Outcomes

Infiltration of thyroid papillary cancer tissue with myeloid leukemic cells: a case report

BACKGROUND

Extramedullary leukemia, also known as myeloid sarcoma, is a rare form of acute myeloid leukemia and often accompanies bone marrow involvement. Myeloid infiltration of the thyroid gland is extremely rare. Here, a unique case in which thyroid cancer tissue was infiltrated with myeloid cells is presented.

CASE PRESENTATION

We present a case of thyroid papillary cancer infiltrated by blastic cells and bilateral breast and axillary myeloid sarcoma in a 30-year-old Caucasian female patient with a history of osteosarcoma and MDS-RAEB2. The patient firstly received 6 cycles of chemotherapy for osteosarcoma, and allogeneic hematopoietic stem cell transplantation was performed after anthracycline-based chemotherapy due to MDS-RAEB2. The patient remained in remission on follow-up in terms of both osteosarcoma and MDS-RAEB2. Malignant features (Bethesda VI) were observed in the fine needle aspiration biopsy performed from a newly developed firm, fixed thyroid nodule approximately 4-5 cm in length in the left thyroid lobe. Because of the Bethesda VI thyroid nodule, the patient underwent total thyroidectomy. In the pathological evaluation, CD34-, CD117-, MPO-, and HLA-DR-positive blastic cells which infiltrated into follicular variant papillary thyroid carcinoma were detected. In the evaluation performed due to blastic cell infiltration, multiple lesions showing increased 18-fluorodeoxyglucose activity in bilateral breast and axillae were detected. Myeloid sarcoma was found as a result of tru-cut biopsy from these lesions. A fungal cystic lesion was detected in the frontal region of the patient who developed altered consciousness after the second cycle of treatment of myeloid sarcoma. During her follow-up in the intensive care unit, she died of cranial septic embolism and acute infarction.

CONCLUSIONS

Here, we present a very interesting case that is the first. A staged approach to diagnosis with methods including immunohistochemical staining, radiological imaging methods, and cytogenetic and molecular analyses can help make the definitive diagnosis.

Extramedullary relapse of acute leukemia after allogeneic hematopoietic stem cell transplantation: different characteristics between acute myelogenous leukemia and acute lymphoblastic leukemia

Extramedullary relapse (EMR) of acute leukemia (AL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a contributor to post-transplantation mortality and remains poorly understood, especially the different characteristics of EMR in patients with acute myelogenous leukemia (AML) and those with acute lymphoblastic leukemia (ALL). To investigate the incidence, risk factors, and clinical outcomes of EMR for AML and ALL, we performed a retrospective analysis of 362 patients with AL who underwent allo-HSCT at the First affiliated Hospital of Soochow University between January 2001 and March 2012. Compared with patients with AML, those with ALL had a higher incidence of EMR (12.9% versus 4.6%; P = .009). The most common site of EMR was the central nervous system, especially in the ALL group. Multivariate analyses identified the leading risk factors for EMR in the patients with AML as advanced disease status at HSCT, hyperleukocytosis at diagnosis, history of extramedullary leukemia before HSCT, and a total body irradiation-based conditioning regimen, and the top risk factors for EMR in the patients with ALL as hyperleukocytosis at diagnosis, adverse cytogenetics, and transfusion of peripheral blood stem cells. The prognosis for EMR of AL is poor, and treatment options are very limited; however, the estimated 3-year overall survival (OS) was significantly lower in patients with AML compared with those with ALL (0 versus 18.5%; P = .000). The characteristics of post-allo-HSCT EMR differed between the patients with AML and those with ALL, possibly suggesting different pathogenetic mechanisms for EMR of AML and EMR of ALL after allo-HSCT; further investigation is needed.

Extramedullary relapse of acute myeloid leukemia after allogeneic hematopoietic stem cell transplantation: an easily overlooked but significant pattern of relapse

Acute myeloid leukemia may manifest as myeloid sarcoma in a variety of extramedullary (EM) tissues at diagnosis or at relapse. Although EM relapse after allogeneic hematopoietic stem cell transplantation (alloSCT) has been considered to be rare, recent studies have suggested that it occurs in 5% to 12% of patients who receive alloSCT, accounting for 7% to 46% of total relapses. The incidence of EM relapse after immunomodulation (eg, donor lymphocyte infusion) or a second SCT is even higher. Moreover, patients with EM relapse are more likely to have had preceding acute graft-versus-host disease or chronic graft-versus-host disease relative to those with bone marrow relapse. Collectively, these observations suggest that the preferential occurrence of the graft-versus-leukemia effect underlies the pathogenesis of EM relapse. Establishing an early diagnosis of EM relapse has been challenging because of the immense diversity in the relapse sites; however, recent studies have suggested the usefulness of (18)F-fluorodeoxyglucose positron emission tomography scans in the detection of EM relapse. As a treatment for EM relapse, a combination of local and systemic therapy should be considered, because local therapy alone often results in subsequent systemic relapse. The prognosis for patients who develop EM relapse after SCT remains poor but is slightly better than that after bone marrow relapse. In addition to an early diagnosis with new modalities, clinical studies using new agents that may offer systemic activity while preserving the graft-versus-leukemia effect are warranted as part of an effort to improve the clinical outcome.