Identification of a new allele HLA-B*40:213 by polymerase chain reaction sequence based typing in a Chinese patient suffering from chloroma

This new HLA-B allele differs from the closest allele B*40:01:01 by two nucleotide changes at codons 102 and 267.

Gemtuzumab Ozogamicin for Relapsed and Refractory Acute Myeloid Leukemia and Myeloid Sarcomas

Antibody-targeted chemotherapy is a promising approach in patients with hematological malignancies. In particular, gemtuzumab ozogamicin (GO, formerly CMA-676), an anti-CD33 antibody linked to calicheamicin, has been approved for the treatment of elderly patients with acute myeloid leukemia (AML) in relapse. Nevertheless, no data are until now available concerning the possible efficacy of GO for myeloid sarcomas (MS). We treated with GO 24 AML patients, in 5 cases presenting with myeloid sarcomas of the skin or bones. The overall complete response rate was 21%. The median duration of response was 6 months. Four out of the 5 patients with myeloid sarcoma showed a regression of the masses, in two cases also obtaining a clearance of marrow blasts. The most common adverse events included thrombocytopenia, neutropenia, infections, elevation of bilirubin and hepatic transaminases. Notably, severe bleeding occurred in 5 cases (21%). VOD was documented in 1 case. We conclude that GO is effective as a single agent in AML and myeloid sarcomas. Further data are required to clarify the possible correlation between GO administration and occurrence of bleeding.

[Extramedullary infiltration of acute monocytic leukemia/monoblastic sarcoma: a clinicopathologic and immunophenotype analysis of 5 cases]

OBJECTIVE

To study the clinicopathologic features, diagnosis and differential diagnosis of extramedullary infiltration of acute monocytic leukemia/monoblastic sarcoma.

METHODS

Five cases of extramedullary infiltration of acute monocytic leukemia/monoblastic sarcoma were selected from 102 cases of myeloid sarcoma diagnosed during the period from 1990 to 2006. The clinicopathologic findings and followup data were retrospectively analyzed. Immunohistochemical study was also carried out with SP method.

RESULTS

Among the 5 cases studied, 3 were males and 2 were females, including 2 children and 3 adults. Generalized lymphadenopathy was found in 4 patients and skin lesions were observed in 2 patients. The tumor cells in all cases were positive for CD68 (KP1), CD68 (PGM1), lysozyme and CD45. They were negative for MPO, CD15, CD163, TdT, CD117, T and B cell markers. The Ki-67 index ranged from 40% to 80%. Follow-up data were available in all the 5 patients. Four of the 5 patients died of the disease, with the average survival time being 6.25 months.

CONCLUSIONS

Monoblastic sarcoma is a rare disease with poor prognosis. It is almost impossible to distinguish monoblastic sarcoma from granulocytic sarcoma and other types of small round cell tumors on the basis of morphologic examination alone. Immunohistochemistry is mandatory for a correct diagnosis.

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.

Sino-orbital chloroma presenting as unilateral proptosis in a boy

Granulocytic sarcoma or chloroma is an unusual localized tumor composed of cells of myeloid origin. Involvement of the orbit and the ethmoid sinuses and presenting as proptosis is rare. Diagnosis could be difficult and delayed when there are no other systemic manifestations, especially with normal peripheral blood and bone marrow picture. We present one such case with unilateral proptosis as the sole presenting sign that posed a diagnostic challenge to us. Orbital decompression by an otolaryngologist may have a role in managing such a case.

Granulocytic sarcoma presenting as bilateral adrenal masses

Granulocytic sarcoma (GS) is a collection of immature myeloid cells contained outside the bone marrow often seen in association with acute myeloid leukemia or as a sign of leukemic transformation in myeloproliferative disorders. Rarely, GS is an isolated finding unaccompanied by another hematological disorder. GS can occur at a variety of sites, most commonly involving the bone, soft tissue, lymph nodes, or skin. We report GS presenting as bilateral adrenal masses in a patient without an antecedent hematologic illness.

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

We report a unique case of aleukemic granulocytic sarcoma of the neck, originally misdiagnosed as non-Hodgkin's lymphoma (NHL), though chloroma was also suspected due to a greenish macroscopic appearance and the presence of myeloid chloroacetate esterase (CAE)+ cells. The proof of clonal T cell receptor gamma chain (TcRgamma) gene rearrangements in the recurring tumor was deemed to confirm the initial diagnosis of T cell NHL. Altogether five distinct types of clonal TcRgamma gene rearrangements were found in the tumor, bone marrow and peripheral blood. Only retrospectively, using RT-PCR, did we detect the acute myeloid leukemia subset-specific fusion gene AML1/ETO in the frozen samples of the relapsed tumor, as well as in the otherwise unaffected bone marrow and peripheral blood (representing 'minimal initial disease' in the latter two samples). Simultaneous staining verified that the neoplastic CAE+ cells and CD45RO+ T cells were different populations.