Angiogenesis plays a key role in solid tumor growth. The purpose of this work was to study angiogenesis in acute myeloid leukemia (AML). We stained bone marrow samples from 20 adult patients with untreated AML and 20 normal controls using endothelial cell markers (ULEX-E and von Willebrand factor [vWF]). The number of vessels per millimeter length of bone marrow core biopsy specimen was scored by light microscopy. Using ULEX-E staining, AML marrows had (average ± SEM) 8.3 ± 3.6 vessels/mm (range, 3.7-19.3), whereas normal marrows had 4.3 ± 1.8 vessels/mm (range, 1.6-7.9). A similar difference was noted using vWF staining (8.6 ± 3.0 vessels/mm vs 4.9 ± 2.2 vessels/mm in AML vs normal bone marrows, respectively). The differences between the numbers of vessels/mm in AML and normal marrows were highly significant (P < .0001 for both ULEX-E and vWF staining). When analyzed by FAB category, there was no difference in the average number of vessels/mm among the different subgroups of AML. Using reverse transcriptase polymerase chain reaction, we observed that the HL-60 and U937 human AML cell lines and 4 of 4 freshly isolated AML cells from untreated patients expressed mRNA for vascular endothelial growth factor (VEGF). Both cell lines as well as all fresh AML isolates tested expressed VEGF protein. Basic fibroblast growth factor was expressed only in HL-60 cells and in only 3 of 4 fresh AML samples. These observations suggest that angiogenesis may play a role in the pathogenesis of AML. Inhibition of angiogenesis could constitute a novel strategy for the treatment of AML. (Blood. 2000;95:309-313).

A b s t r a c t Extramedullary plasmacytoma (EMP),

Background Accurate quantification of malignant cells in the peripheral blood of patients with cutaneous T cell lymphoma (CTCL) is important for early detection, prognosis, and monitoring disease burden. Objective Determine the spectrum of current clinical practices; critically evaluate elements of current ISCL B1 and B2 staging criteria; and assess the potential role of TCR-Vβ analysis by flow cytometry. Methods We assessed current clinical practices by survey, and performed a retrospective analysis of 161 patients evaluated at Yale (2011-2014) to compare the sensitivity, specificity, PPV, and NPV of parameters for ISCL B2 staging. Results There was heterogeneity in clinical practices among institutions. ISCL B1 criteria did not capture five Yale cohort patients with immunophenotypic abnormalities who later progressed. TCR-Vβ testing was more specific than PCR and aided diagnosis in detecting clonality, but was of limited benefit in quantification of tumor burden. Limitations Because of limited follow-up involving a single center, further investigation will be necessary to conclude whether our proposed diagnostic algorithm is of general clinical benefit. Conclusion We propose further study of “modified B1 criteria”: CD4/CD8 ratio ≥5, %CD4+/CD26- ≥ 20%, %CD4+/CD7- ≥ 20%, with evidence of clonality. TCR-Vβ testing should be considered in future diagnostic and staging algorithms.

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Extramedullary hematopoiesis (EMH) in the spleen is a characteristic feature of the chronic myeloproliferative disorders (CMPDs) and various other neoplastic or reactive myeloid conditions. However, the origin of these hematopoietic precursor cells and the molecular mechanisms underlying their development in the spleen is uncertain. The V617F mutation in the Janus Kinase 2 gene (JAK2 V617F ) was recently shown to be frequently and preferentially present in the peripheral blood and bone marrow cells of CMPD patients, and the resulting dysregulation of its downstream targets is important to CMPD pathogenesis. To determine the occurrence and potential role of JAK2 V617F in splenic EMH cells, we studied splenectomy specimens from 47 patients with significant EMH. JAK2 V617F was detected by real-time PCR melting curve analysis in 22 specimens, including 11/17 chronic idiopathic myelofibrosis, 7/7 polycythemia vera, 1/1 essential thrombocythemia, 1/3 CMPD unclassifiable, 1/5 chronic myelomonocytic leukemia, 0/5 chronic myelogenous leukemia, 1/3 myelodysplastic syndrome and 0/6 acute myeloblastic leukemia cases, whereas only the JAK2 wild-type allele was detected in the other 25. Nineteen of 20 cases with adequate bone marrow samples available for molecular examination demonstrated concordant JAK2 genotypes. Laser-capture microdissection was then used to enrich the EMH and non-EMH splenic cell fractions, confirming that the mutant alleles specifically originated from the EMH cells. Furthermore, megakaryocytes in the JAK2 V617F -positive splenectomy specimens expressed higher levels of Bcl-xL, an antiapoptotic protein and downstream target of the JAK2/STAT5 pathway. Thus, JAK2 V617F is frequently present in splenic EMH cells associated with CMPD, but it is rarely identified in splenic EMH cells associated with other myeloid disorders. Our results indicate that the precursor cells leading to extramedullary hematopoietic expansion in CMPD most likely originate from the transformed bone marrow clone. Also, dysregulation of downstream pathways such as Bcl-xL may be important to CMPD disease pathogenesis in the spleen. Modern Pathology (2007) 20, 929-935;

Angiomatoid fibrous histiocytoma (AFH) is generally considered a soft tissue sarcoma of low malignant potential that occurs in children/young adults and most frequently affects the extremities. AFH infrequently recurs and rarely metastasizes. AFH has a characteristic histomorphology, and immunohistochemical reactivities for desmin and CD68 have led to myofibroblastic and fibrohistiocytic histogenetic hypotheses, respectively. Although only a limited number of AFH cases have been molecularly characterized, many have demonstrated evidence of an underlying translocation event. Reverse transcription-polymerase chain reaction and fluorescence in situ hybridization studies suggest that chromosomal rearrangement in AFH most frequently involve the EWS, CREB, ATF-1, and FUS genes. We report the first pathologically confirmed case of an AFH presenting as an intracerebral primary in a previously healthy 25-year-old man. Genetic analyses revealed a t(12;22)(q13;q12) and a unique underlying clear cell sarcomalike type 1 EWS/ATF-1 gene fusion.

Angiogenesis plays a key role in solid tumor growth. The purpose of this work was to study angiogenesis in acute myeloid leukemia (AML). We stained bone marrow samples from 20 adult patients with untreated AML and 20 normal controls using endothelial cell markers (ULEX-E and von Willebrand factor [vWF]). The number of vessels per millimeter length of bone marrow core biopsy specimen was scored by light microscopy. Using ULEX-E staining, AML marrows had (average ± SEM) 8.3 ± 3.6 vessels/mm (range, 3.7-19.3), whereas normal marrows had 4.3 ± 1.8 vessels/mm (range, 1.6-7.9). A similar difference was noted using vWF staining (8.6 ± 3.0 vessels/mm vs 4.9 ± 2.2 vessels/mm in AML vs normal bone marrows, respectively). The differences between the numbers of vessels/mm in AML and normal marrows were highly significant (P < .0001 for both ULEX-E and vWF staining). When analyzed by FAB category, there was no difference in the average number of vessels/mm among the different subgroups of AML. Using reverse transcriptase polymerase chain reaction, we observed that the HL-60 and U937 human AML cell lines and 4 of 4 freshly isolated AML cells from untreated patients expressed mRNA for vascular endothelial growth factor (VEGF). Both cell lines as well as all fresh AML isolates tested expressed VEGF protein. Basic fibroblast growth factor was expressed only in HL-60 cells and in only 3 of 4 fresh AML samples. These observations suggest that angiogenesis may play a role in the pathogenesis of AML. Inhibition of angiogenesis could constitute a novel strategy for the treatment of AML. (Blood. 2000;95:309-313).

No abstract