Myeloblastoma (chloroma) in leukemia: case 2. Meningeal granulocytic sarcoma (chloroma) in essential thrombocythemia

RNA sequencing of myeloid sarcoma, shed light on myeloid sarcoma stratification

BACKGROUND

Myeloid sarcoma (MS) is a rare, extramedullary tumor consisting of myeloid blasts. Little is known about the genetic background of MS and the prognostic value of genetic abnormalities in MS. In particular, the broad variety of gene fusions that occur in MS is marginally covered by traditional testing methods due to lack of fresh tumor specimens.

METHODS

Here, we analyzed the clinical and genetic features of 61 MS cases. We performed RNA sequencing (RNA-seq) on formalin-fixed paraffin-embedded (FFPE) or fresh samples to analyze fusion genes in 26 cases. In addition, we performed genetic abnormalities-based risk stratification using fusion genes and gene mutations.

RESULTS

A total of 305 fusion genes were identified in 22 cases, including the following five recurrent fusion genes: RUNX1-RUNX1T1, CBFβ-MYH11, ETV6-MECOM, FUS-ERG, and PICALM-MLLT10. The prognosis in the adverse-risk group was significantly worse than that in the favorable/intermediate-risk group (median survival: 12 months vs. not reached; p = 0.0004).

CONCLUSION

These results indicated the efficacy of RNA-seq using FFPE-derived RNA as a clinical routine for detecting fusion genes, which can be used as markers for risk stratification in MS.

Granulocytic sarcoma: 32 cases and review of the literature

Thirty-two cases of granulocytic sarcoma (GS) are reported in this paper. Age range was from 16 - 70 years. GS was accompanied by AML in 13 cases, ALL (My+) in one case, CML in 11 cases and MDS in two cases. GS was diagnosed simultaneously with leukemia in five cases and preceded the leukemia in eight. Lymph node and soft tissue were the most commonly detected localizations. Seven cases had first been diagnosed as NHL. Histopathologically blastic, immature and mature variants were found in 11, nine and 11 cases respectively and overall survival was shortest in the blastic type. Myeloperoxidase and lysozyme were found to be positive in 30 and 24 cases respectively. Therapy was radiation in five cases and surgery in three. Systemic chemotherapy was given to the cases. The clinical outcome of the patients after the diagnosis of GS was poor. GS is a unique entity; prognosis is poor but it is important to detect the signaling pathways associated with migration of myeloid cells to the extra-medullary tissues. The critical factors for detecting this interesting tumor are to be aware of this disease, cooperation between clinician and pathologist and the application of special stains to detect the myeloid origin.

Multiple granulocytic sarcomas in essential thrombocythemia

A 59-year-old woman was diagnosed with essential thrombocythemia in 1988 and had been treated with hydroxyurea, mitobronitol, busulfan, and ranimustine, in that order. Hepatosplenomegaly, low-grade fever, and body weight loss manifested, and a few blasts were noted in the peripheral blood studied in March 2002. A biopsied specimen of the bone marrow showed myelofibrosis but not a leukemia in August 2004. An abnormal karyotype with der(1; 13) appeared for the first time. She was treated with low-dose prednisolone. In January 2005, she experienced left hip joint pain, and magnetic resonance scanning showed a tumoral lesion in the femoral head. Histological diagnosis of the biopsied mass revealed that it was a granulocytic sarcoma, and radiotherapy was performed. In April 2005, bone scintigraphy showed multiple lesions. She became febrile and red blood cell transfusion-dependent with hepatosplenomegaly and a small number of circulating blasts. Intravenous cytarabine (low dose) and etoposide relieved the fever and hepatosplenomegaly; however, she developed a pathologic fracture of the right humerus. An additional karyotypic abnormality (7q22 deletion) was noted. She subsequently died of infection. Granulocytic sarcoma is very rare in essential thrombocythemia, and this patient may be the first reported case of essential thrombocythemia that developed multiple lesions and a pathologic fracture without transformation to overt leukemia.

Myeloid sarcoma: clinico-pathologic, phenotypic and cytogenetic analysis of 92 adult patients

Myeloid sarcoma (MS) is a rare neoplasm whose knowledge is largely based on case reports and/or technically dated contributions. Ninety-two MSs in adulthood with clinical data available were evaluated both morphologically and immunohistochemically. Seventy-four cases were also studied by fluorescent in situ hybridization on tissue sections and/or conventional karyotyping on bone marrow or peripheral blood. Histologically, 50% of the tumors were of the blastic type, 43.5% either monoblastic or myelomonocytic and 6.5% corresponded to different histotypes. CD68/KP1 was the most commonly expressed marker (100%), followed by myeloperoxidase (83.6%), CD117 (80.4%), CD99 (54.3%), CD68/PG-M1 (51%), CD34 (43.4%), terminal-deoxy-nucleotidyl-transferase (31.5%), CD56 (13%), CD61/linker for activation of T cells (2.2%), CD30 (2.2%) and CD4 (1.1%). Foci of plasmacytoid monocyte differentiation were observed in intestinal cases carrying inv16. Chromosomal aberrations were detected in about 54% of cases: monosomy 7(10.8%), trisomy 8(10.4%) and mixed lineage leukemia-splitting (8.5%) were the commonest abnormalities, whereas t(8;21) was rare (2.2%). The behavior was dramatic irrespective of presentation, age, sex, phenotype and cytogenetics. Most if not all, long survivors received bone-marrow transplantation. The present report expands the spectrum of our knowledge showing that MS has frequent monoblastic/myelomonocytic differentiation, displays distinctive phenotypic profile, carries chromosomal aberrations other than t(8;21), and requires supra-maximal therapy.

Neurologic Complications of Lymphoma and Leukemia

Lymphoma and leukemia are systemic diseases that affect many end-organs, including the central nervous system. These cancers may directly affect the central or peripheral nervous systems by the production of intraparenchymal or extra-axial mass lesions or by meningeal infiltration. Vascular occlusion may occur as a result of blockage of blood vessels by tumor cells. A variety of paraneoplastic syndromes occur and are most commonly associated with plasma cell tumors. Coagulopathy and metabolic disturbances are direct and indirect effects of these cancers and also are associated with their treatment, resulting in disturbances of consciousness, intracranial hemorrhage, or ischemic stroke. The agents used in the treatment of lymphoma and leukemia are also associated with neurological toxicity. This chapter reviews these neurological manifestations of lymphoma and leukemia and their therapies.

Aberrant p15 gene promoter methylation in therapy-related myelodysplastic syndrome and acute myeloid leukaemia: clinicopathological and karyotypic associations

Seventeen patients with therapy-related myelodysplastic syndrome/acute myeloid leukaemia (t-MDS/AML) were examined for aberrant p15 gene methylation by methylation-specific polymerase chain reaction. Ten patients (58%) showed p15 methylation, which was significantly related to monosomy/deletion of chromosome 7q, but not to antecedent chemotherapy, blast count, leukaemic evolution or survival. In three of six patients with marrow samples obtained prior to the diagnosis of t-MDS/AML, p15 methylation predated disease development by up to 2 years. Bone marrow transplantation led to the disappearance of p15 methylation in one patient. These results showed that p15 methylation was an early event in the evolution of some t-MDS/AML patients.