[GUIDELINES FOR DIAGNOSIS AND TREATMENT OF PATIENTS WITH MYELODYSPLASTIC SYNDROME].

Myelodysplastic syndrome Working Group of the Croatian Cooperative Group for Hematologic Diseases (CROHEM), Referral center of the Ministry of Health of the Republic of Croatia for diagnostics and treatment of MDS, as well as the Croatian Society for Haematology of the Croatian Medical Association have made Croatian guidelines for diagnosis and treatment of myelodysplastic syndrome (MDS). MDS is a heterogeneous group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, dysplasia, cytopenia and risk of transformation to acute myeloid leukemia (AML). Diagnosis is based on morphological characteristics of hematopoietic cells supplemented with the cytogenetic analysis and bone marrow flow cytometry. Due to great differences in the natural course of the disease, i.e. time to progression to AML and the expected time of survival several scoring systems have been developed to determine the disease risk. The treatment of patients with MDS is based on the risk factors of the disease as well as the individual risk of treatment.

Imaging­based diagnosis of intrapancreatic accessory spleen: A case report.

During a routine ultrasound examination of the abdomen, a 60-year-old male patient was diagnosed with mass in the tail of the pancreas. However, computed tomography (CT) suggested that the lesion was an intrapancreatic accessory spleen (IPAS). IPAS is a congenital anomaly, which usually does not present with symptoms. IPAS occurs during embryologic splenic development when a portion of the splenic tissue fails to fuse with the main body of the spleen. IPAS does not require treatment, except when it is combined with idiopathic thrombocytopenic purpura. In the present case, the diagnosis of IPAS was confirmed using magnetic resonance imaging (MRI). On CT and MRI, the IPAS had a density and intensity comparable with that of the spleen in all plain and contrast-enhanced phases. Due to comorbidities, the patient refused further evaluation or surgery. The lesion was periodically monitored using CT every 1-2 years. Since the tumour was stable during the 7-year follow-up, it was concluded that it was an IPAS. In patients that cannot undergo surgery, a characteristic location (near the spleen) and imaging features (such as a 'zebra-patterned' enhancement in the arterial phase on CT and high signal intensity on diffusion-weighted imaging sequences on MRI, which is comparative to that of the normal spleen) may allow for a diagnose of IPAS with a high level of certainty. Being aware of this condition could aid a correct diagnosis of IPAS and prevent unnecessary surgery.

Analysis of Ikaros family splicing variants in human hematopoietic lineages.

Transcription factors from the Ikaros family are involved in lymphocyte differentiation and have a critical role at specific check points of the haemopoietic pathway. However, how developmentally regulated changes are reflected in gene expression programs of lymphocyte differentiation is not well understood. It has been suggested that disregulation of transcription factors from the Ikaros family is associated with the development of different human leukemias. In this work we analyzed the state of Ikaros family members in different leukemic cells with the aim to explore the transcriptional control of human hematopoietic lineages and shed some new light on our understanding of transcription factor significance in human leukemias. By means of RT-PCR and specific primers we investigated the expression of Ikaros, Aiolos and Helios transcription factors and their splicing variants in seven leukemia cell lines derived from different types of leukemia (ALL, CML, AML) and lymphoma (histiocytic lymphoma, Burkitt lymphoma and anaplastic large cell lymphoma). In all of the cell lines examined Ikaros was present in dominant Ik1 to Ik4 isoforms and small Ik6 isoform was absent. Aiolos was expressed in the majority of the cell lines, of both, B and T origin, in the form of the full length Aio1. Helios was also present only in two long isoforms Hel1 and Hel2, and was absent in one third of the lines. Similar distribution of positive and negative expression of Aiolos and Helios found in various types of leukemias could implicate common pathways of their regulation.

An unusual presentation of Gaucher's disease: aortic valve fibrosis in a patient homozygous for a rare G377S mutation.

Gaucher's disease (GD) has variable presentations, but cardiac involvement is a generally uncommon clinical manifestation of the disease. In the past 25 years, the underlying genetic disorder in GD has been well characterized, with almost 300 mutations identified in the glucocerebrosidase gene (GBA). Nevertheless, clear genotype-phenotype correlations have been confirmed only for the most frequent mutations. We present a female patient, who was known to have aortic valve pathology from the age of 30. Despite medical follow up, at the age of 60 she presented with heart failure (NYHA III). At that time echocardiography showed severe fibrosed aortic valve stenosis. Valvuloplasty was planned, when thrombocytopenia, previously considered to be autoimmune, became severe. Anemia and leukopenia were also noted. Moderate splenomegaly and severe bone marrow infiltration were found on MRI. Bone marrow aspiration revealed typical Gaucher cells and the enzyme activity assay confirmed the diagnosis. DNA investigation showed that the patient is homozygous for the G377S mutation. To our knowledge, of all mutations identified so far, only homozygosity for the D409H mutation has been associated with cardiovascular valvular disease in patients with a rare type 3c GD. G377S, found in our patient, is a rare mutation, previously reported as a 'mild' mutation, because of the finding that homoallelic patients were essentialy asymptomatic or had mild disease. Our patient, also homozygous for G377S mutation, had a severe form of type 1 GD, with rare cardiac valve involvement, which is a previously unreported clinical presentation for this mutation. This case further proves that patients with the same genotypes can have different phenotypes, emphasizing the influence of other genetic and/or environmental factors.

Multimodal image analysis of chronic leukemic lymphoproliferative disorders and the hypothesis of "single" and "multiple" programmed stops in the development of typical and atypical forms of leukemias and lymphomas.

The study consisted of morphometric analysis, assessment of the argyrophilic nucleolar organization region (AgNOR) characteristics, and image cytometry (ICM) in different tumor mass compartments: bone marrow (BM), peripheral blood (PB) and lymph nodes (LN) from patients with chronic leukemic lymphoproliferative disorders. A total of 71895 cells were analyzed on SFORM PC (VAMSTEC, Zagreb). Correlation between morphometric, AgNOR and ICM characteristics revealed the cells with low proliferative activity to possess small, homogeneous AgNOR, with the majority of cells in the peak of DNA histogram. The cells with high proliferative activity had inhomogeneous AgNOR, mostly containing greater DNA content than peak cells, pathologic mitoses (DNA > 4N), or the majority of cells were in the S-phase of the cell cycle. Cells with medium proliferative activity and annular AgNOR were in-between. Analysis of different tumor mass compartments showed that lymphatic cells with the affinity to accumulate in BM regularly exhibited low proliferative activity (a lower percentage of cells in SFC and highest percentage of cells in the peak of the G0/G1 phase). The cells in LN exhibited the characteristics of proliferative cells (an increased number of AgNOR, larger and more proliferative inhomogeneous AgNOR, and lowest percentage of cells in the G0/G1 phase). The migration of cells from BM to LN and between lymph nodes occurred through PB (there were cells with low and high proliferative activity: a higher proportion of cells in SFC and at the same time in the G0/G1 phase of the cell cycle). Analysis of cell size and proliferative activity in different compartments of tumor mass revealed that the cells in BM and PB did not differ substantially according to size and proliferative activity, while an inverse pattern was observed between PB and LN. As small cells are inactive and larger cells more proliferative, the analysis quite unexpectedly showed the PB cells to be largest and most inactive, in contrast to LN where the cells were smallest and most active. The "single" and "multiple programmed stops" have been hypothesized in the development of typical forms of leukemias and lymphomas and atypical forms of subacute and subchronic leukemias. Differentiation impairment may occur at any stage, and different "stop" locations result in different morphology and affinity to accumulation in bone marrow, peripheral blood and lymph nodes.