Extramedullary infiltrates at diagnosis have no prognostic significance in children with acute myeloid leukaemia

Genomic profiling of myeloid sarcoma by array comparative genomic hybridization

Myeloid sarcoma (MS) is a tumor mass of myeloblasts or immature myeloid cells occurring in an extramedullary site. In this study, seven cases of MS [stomach (1), testis (1), skin (2), and lymph node (3)] and 3 synchronous and 1 follow-up bone marrow (BM) samples were studied for genomic abnormalities using array comparative genomic hybridization (array-CGH). Array-CGH construction used approximately 5,400 bacterial artificial chromosome clones from the RPCI-11 library, spanning the human genome. Data were analyzed using the DNAcopy software and custom heuristics. All MS cases had genomic abnormalities detected by array-CGH. Unbalanced genomic abnormalities in five MS cases were confirmed by conventional cytogenetics (CC) and/or fluorescence in situ hybridization (FISH); these abnormalities included loss of 4q32.1-q35.2, 6q16.1-q21, and 12p12.2-p13.2 and gain of 8q21.2-q24.3, 8, 11q21-q25, 13q21.32-q34, 19, and 21. Array-CGH was also invaluable in identifying possible deletions, partner translocations, and breakpoints that were questionable by CC. The remaining two MS cases had genomic aberrations detected by array-CGH, but were not studied further by CC/FISH. Chromosome 8 was most commonly abnormal (3/7 cases). Identical genomic abnormalities were demonstrated in MS and in synchronous BM in two cases. These results demonstrate that array-CGH is a powerful tool to screen MS tissue for unbalanced genomic abnormalities, allowing identification of chromosome abnormalities when concurrent BM is nonanalyzable or nonleukemic.

Extramedullary hematopoietic proliferations, extraosseous plasmacytomas, and ectopic splenic implants (splenosis)

Hematopoietic proliferations are well known to present ectopically outside the bone marrow, either in benign or malignant form. As such, they present a distinct problem with respect to morphologic interpretation because of their uncommonality in extramedullary sites and their capacity to simulate other lesions histologically. This review considers extramedullary myeloid tumors ("granulocytic sarcoma," "erythroblastic sarcoma," "megakaryocytic sarcoma"), tumefactive extramedullary hematopoiesis, and the peculiar condition known as "splenosis," with consideration of their clinical, microscopic, and cytohistochemical chararacteristics.

Children with acute myeloblastic leukemia presenting with extramedullary infiltration: the effects of high-dose steroid treatment

To evaluate whether children with acute myeloblastic leukemia (AML) presenting with extramedullary infiltration (EMI) have different clinical, morphologic features and prognosis from children without EMI, a 127 consecutive previously untreated children with AML were entered in this study. Fifty-one children (40%) had EMI at diagnosis and 27% of these showed multiple site involvement. Twenty-seven of 127 children (21%) presented myeloid tumors. No age related differences in the incidence of EMI was noted. However, analysis of clinical and biological features at diagnosis showed that WBC count > or =50 x 10(9) l(-1), hepatosplenomegaly >5 cm, FAB AML-M4 and AML-M5 subtypes and CD13, CD14 expression of bone marrow (BM) leukemic cells (>20%) were more frequent in children with EMI. Two consecutive treatment protocols were used. In both protocols remission was achieved with combined high-dose methylprednisolone (HDMP) as a differentiating and apoptosis inducing agent with mild cytotoxic chemotherapy (low-dose cytosine arabinoside (LD Ara-C), weekly mitoxantrone and Ara-C or 6-thioguanine). Administration of short-course (4-7 days) HDMP (20-30 mg/kg per day) alone resulted in a remarkable decrease in peripheral blood, BM blasts and in the size of EMI in responding patients. In both protocols, remission rate in patients with EMI was 71 and 80%, which was lower than that of the patients without EMI (87 and 89%). This may be attributed to the higher frequency of unfavorable features in children with EMI. However, in patients who presented with myeloblastoma and treated with a more intensive post-remission therapy (AML-94), the 4-year disease-free survival (DFS) and event-free survival (EFS) rates were not found to be significantly different from children who had no EMI (P>0.05). Whereas, the outcome of children who presented with gingival infiltration did not improve. In further studies, the prognostic significance of different localisation of EMI and the effect of addition of HDMP to cytotoxic chemotherapy should be explored in larger series.

Acute myeloid leukemia mimicking primary testicular neoplasm. Presentation of a case with review of literature

We describe a new unique case of acute myeloid leukemia (AML) in a 21-yr-old male presenting with abdominal pain, bilateral testicular masses and gynecomastia. Further work-up with computed tomography of the chest, abdomen and pelvis revealed massive retroperitoneal, peripancreatic and mediastinal lymphadenopathy, suggesting primary testicular neoplasm. The patient was subjected to right orchiectomy that showed infiltration of testicular tissue with malignant cells, originally misinterpreted as undifferentiated carcinoma. Immunohistochemistry studies, however, showed these cells to be strongly positive for myeloperoxidase and CD45, indicating a myeloid cell origin. Bone marrow (BM) aspirate and biopsy demonstrated replacement of marrow with immature myeloid cells. Both the morphology and immunophenotype of the blast cells were consistent with AML type M4 (acute myelo-monocytic leukemia), using French-American-British (FAB) classification. The patient received standard induction chemotherapy with cytosine arabinoside (ARA-C) and daunorubicin followed with two cycles of consolidation therapy with high dose ARA-C, which resulted in remission of BM disease and resolution of lymphadenopathy and left testicular masses. After the second cycle of consolidation therapy, the patient developed sepsis that was complicated by refractory disseminated intravascular coagulopathy. He expired with a clinical picture of multiple organ failure. The unique features of this case are presented and the related literature is reviewed.

Characteristics and outcome of t(8;21)-positive childhood acute myeloid leukemia: a single institution's experience

To elucidate the clinical and biological features of childhood acute myeloid leukemia (AML) with the t(8;21), we reviewed the records of patients with AML treated at St Jude Children's Research Hospital over a 17-year period (1980 to 1996). Of 298 patients with AML, 40 (13%) had blast cells that contained the t(8;21). This translocation was associated with a high frequency of French-American-British M2 morphology (82%) and the presence of granulocytic sarcoma (23%). Molecular analysis detected the AML1-ETO fusion transcript in all 25 cases with the t(8;21) tested, but failed to identify additional cases with AML1-ETO among the 127 cases with other cytogenetic findings. Compared to patients with other genetic abnormalities, those with the t(8;21) were less likely to have internal tandem duplications of the FLT3 gene (none of 10 vs 16 of 68). The 6-year overall survival estimate was 55% +/- 9% and the event-free survival estimate, 33% +/- 7%. Of the clinical and biological features examined, only gender was prognostically significant: the 6-year overall survival estimate for males was 68% +/- 10%, compared to 33% +/- 11 for female patients (P = 0.03). Treatment outcome was not influenced by the chemotherapy regimen used or by the use of autologous hematopoietic stem cell transplantation. These results suggest that t(8;21)-positive AML represents a heterogeneous disease with variable outcome. The reported favorable outcome for t(8;21)-positive AML in other studies may be due to the use of high-dose cytarabine.

Acute myeloid leukemia with inv(16)(p13q22): involvement of cervical lymph nodes and tonsils is common and may be a negative prognostic sign

Acute myeloid leukemia (AML) with inv(16)(p13q22) or the variant t(16;16)(p13;q22), is strongly associated with the FAB subtype M4Eo. A high incidence of CNS involvement was reported in the 1980s, but otherwise little is known about the pattern of extamedullary leukemia (EML) manifestations in this AML type. We have compiled clinical and cytogenetic data on 27 consecutive AML cases with inv(16)/t(16;16) from southern Sweden. In general, these AMLs displayed the clinical features that have previously been described as characteristic for this disease entity: low median age, hyperleukocytosis, M4Eo morphology, and a favorable prognosis. However, CNS leukemia was only seen in relapse in one patient diagnosed in 1980, whereas the most common EML manifestation in our series was lymphadenopathy (5/27, 19%), most often cervical with or without gross tonsillar enlargement. A review of previously published, clinically informative cases corroborates that lymphadenopathy, with preference for the cervical region, is the most common EML at diagnosis in inv(16)-positive AML (58/175, 33%). CNS leukemia, on the other hand, has been reported in only 17% of the cases, mostly in the relapse setting, with a diminishing frequency over time, possibly due to protective effects of high-dose cytarabine. Other reported EML sites include the scalp, ovaries, and the intestine. Cervicotonsillar EML was in our series associated with a shorter duration of first remission, (P < 0.05), and may hence prove to be an important clinical parameter when deciding treatment strategies in AML with inv(16)/t(16;16).

Isolated myelosarcoma in children--update and review

Primary myelosarcomas, also called leukemia cutis, granulocytic sarcomas or chloromas, are rare extramedullary manifestations of acute myeloid leukemia (AML) which precede bone marrow involvement. Skin infiltration was the most frequent localization associated with a myelomonocytic differentiation. Although first remission was achieved by most children, risk of relapse seemed to be increased. This might be caused by the specific biology of myelosarcomas, but also may be the result of delayed or reduced treatment. During the AML-BFM-studies 87/93/98 (11/1987-7/2000) 37 children with isolated myelosarcomas were diagnosed. Eighteen of the 37 patients survived with a 5-year overall survival estimation of 0.54+/-0.09 compared to 0.59+/-0.02; p(log rank) = 0.94. However, reduced or delayed treatment in 17 children led to an increased relapse rate of 71% compared to 35% in children treated soon after diagnosis. The 5-year overall survival in these patients was 0.41+/-0.11. According to our experience and review of the literature, an early diagnostic workup is needed in children with unusual skin lesions or tumors, considering myelosarcoma as primary manifestation of AML. Intensive AML-specific chemotherapy is generally recommended soon after diagnosis.