Aleukemic granulocytic sarcoma with AML1/ETO fusion gene expression and clonal T cell populations

Aleukemic extramedullary T lymphoid/myeloid bilineage hematopoietic and lymphoid malignancy with progression to bilineage leukemia at relapse: A case report

Bilineage T lymphoid and myeloid (T/My) neoplasms are rare entities among the hematopoietic and lymphoid malignancies. The majority of patients present with leukemic symptoms in which blasts are observed in the peripheral blood (PB) or bone marrow (BM) at a percentage of >20% of nucleated cells. Only a minimal number of cases of T/My bilineage hematopoietic and lymphoid malignancy have been reported with extramedullary infiltration as the initial symptom. The origin of the neoplastic cells in T/My bilineage malignancy has been documented as the hematopoietic stem cells. The present study reports the case of a 31-year-old man with a T/My bilineage malignancy, which initially showed cervical lymph node enlargement beyond the diagnostic criteria of leukemia in the PB and in the BM. Two distinct malignant populations were detected in the cervical lymph node and pleural effusion, one of which was positive for MPO-staining, while the other was positive for cytoplasmic cluster of differentiation 3. Mutations in platelet-derived growth factor receptor α, platelet-derived growth factor receptor β, fibroblast growth factor receptor 1 and other chromosome abnormalities were excluded. The patient obtained complete remission after conventional chemotherapy, but relapsed with bilineage leukemia within a short period of time. Lymphoid and myeloid lineages have been reported to be differentiated from multipotent progenitors asymmetrically. However, the cellular mutation stage in T/My bilineage malignancy remains unclear. The present study also reviews the origin, development and therapeutic strategies for extramedullary T/My bilineage malignancy.

Cardiac granulocytic sarcoma diagnosed by intracardiac echocardiography-guided biopsy

A 52-year-old man presented with clinical and echocardiographic signs of cardiac tamponade. A transthoracic echocardiogram revealed a large right atrial mass that obstructed the superior vena cava flow. Cardiac magnetic resonance imaging and computed tomography demonstrated extracardiac tumour invasion of the free atrial wall extending to the right pulmonary hilus. Intracardiac echocardiography-guided biopsy of the tumour revealed the tissue diagnosis-granulocytic sarcoma of the heart. The patient was effectively treated with radiotherapy, chemotherapy and allogeneic haematopoietic stem cell transplantation. He has remained free of the disease for 12 months after treatment.

Precursor B lymphoblastic leukemia 32 months after local therapy for a primary extramedullary myeloid cell tumor

A primary extramedullary myeloid cell tumor (pEMT) of an inguinal lymph node was completely excised without subsequent anti-tumor therapy in a 6-year-old child. Clinical observation and monitoring of blood and bone marrow (BM) did not reveal any pathologic results before 32 months, when a precursor B lymphoblastic leukemia was diagnosed. Identical T-cell receptor gamma rearrangement in nodal pEMT and in precursor B lymphoblastic leukemia in BM indicates a clonal relationship of these two tumors.

Myeloid sarcoma: clinical and morphologic criteria useful for diagnosis

Extramedullary accumulation of myeloblasts or immature myeloid cells form tumors called myeloid sarcoma in the WHO classification. Such tumors develop in lymphoid organs, bone (skull, orbit, etc.), skin, soft tissue, various mucosae and organs, and the CNS. They may precede or occur concurrently with acute myeloid leukemia, or reveal blastic transformation of chronic myeloproliferative disorders or myelodysplastic syndromes. They may also reveal relapses in treated patients. They are constituted by a diffuse infiltrate made up of medium-to-large cells. The cells are difficult to identify. Imprints are very useful. Immunohistochemistry can help diagnose and distinguish four variants: granulocytic myeloperoxidase (MPO+, CD 68+ [KP1+/-, PGM1-] lysozyme+, CD 34+/-), monoblastic (MPO-, CD 68+, [KP1+, PGM1+] lysozyme+, CD 34-), myelomonoblastic (MPO-, CD 68+, [KP1+, PGM1+] lysozyme+, CD 34-), or megakaryoblastic (positivity for factor VIII, CD 61, CD 31). Immunohistochemistry sometimes demonstrates expression of CD 43, CD 7, CD 79a, and CD 56 (particularly the monoblastic variant with t[8;21]). Recently the demonstration of CD 99 and CD 117, which can now be done on paraffin sections, may be useful to identify blasts of granulocytic origin. The diagnosis is missed in about 50% of cases when immunohistochemistry is not used. Patients with myeloid sarcomas should be treated in the same way as patients with acute myeloblastic leukemia. Disease progression and prognosis are similar for the two conditions.