Bohring–Opitz syndrome (BOS) is a medical syndrome caused by a mutation in the ASXL1 gene. It is diagnosed by genetic testing and is characterised by characteristic craniofacial appearance, fixed contractures of the upper limbs, abnormal posture, feeding difficulties, intellectual disability, small size at birth, and failure to thrive. Some of these features are shared with other genetic syndromes.

Genetically, de novo truncating mutations in ASXL1 have been shown to account for approximately 50% of Bohring–Opitz syndrome cases.

The syndrome is extremely rare, with fewer than 80 known cases worldwide. The leading cause of death is respiratory infections. Children with BOS can have feeding difficulties, recurring respiratory infections, sleep apnea, developmental delay, failure to thrive, abnormal hair density and length, Wilm’s Tumors, brain abnormalities, silent aspiration, and other issues.

The Düsseldorf score stratifies cases using four categories, giving one point for each; bone marrow blasts ≥5%, LDH >200U/L, haemoglobin ≤9g/dL and a platelet count ≤100,000/uL. A score of 0 indicates a low risk group' 1-2 indicates an intermediate risk group and 3-4 indicates a high risk group. The cumulative 2 year survival of scores 0, 1-2 and 3-4 is 91%, 52% and 9%; and risk of AML transformation is 0%, 19% and 54% respectively.

The International Prognostic Scoring System (IPSS) was developed in the mid-1990s to assess the prognosis of MDS patients. This system stratifies cases into 2 groups; a lower-risk group (sub divided into low and intermediate-1) and a higher risk (subdivided into intermediate-2 and high). It uses the blast percentage, number of cytopaenias and bone marrow cytogenetics data to place cases of CMML into these groups. Due to the scoring system being developed for MDS, the more myeloproliferative cases of CMML (WBC >13x10) are excluded from the scoring system. Although the IPSS scoring system is used clinically, there is a high variability in each group. For this reason, new modalities for assessing prognosis in MDS (and CMML) are being developed.

Primary myelofibrosis (PMF) is associated with the "JAK2V617F" mutation in up to 50% of cases, the "JAK2" exon 12 mutations in 1-2% of cases, and the MPL (thrombopoietin receptor) mutation in up to 5% of cases:

- Prefibrotic/cellular phase - increased, small and atypical megakaryocytes which cluster, reticulin fibrosis, later trichrome (collagenous) fibrosis, and increased myeloid precursors

- Fibrotic phase - collagenous fibrosis with lack of marrow elements

While investigational drug therapies exist, no curative drug treatment exists for any of the MPDs. The goal of treatment for ET and PV is prevention of thrombohemorrhagic complications. The goal of treatment for MF is amelioration of anemia, splenomegaly, and other symptoms. Low-dose aspirin is effective in PV and ET. Tyrosine kinase inhibitors like imatinib have improved the prognosis of CML patients to near-normal life expectancy.

Recently, a "JAK2" inhibitor, namely ruxolitinib, has been approved for use in primary myelofibrosis. Trials of these inhibitors are in progress for the treatment of the other myeloproliferative neoplasms.

The first clue to a diagnosis of AML is typically an abnormal result on a complete blood count. While an excess of abnormal white blood cells (leukocytosis) is a common finding with the leukemia, and leukemic blasts are sometimes seen, AML can also present with isolated decreases in platelets, red blood cells, or even with a low white blood cell count (leukopenia). While a presumptive diagnosis of AML can be made by examination of the peripheral blood smear when there are circulating leukemic blasts, a definitive diagnosis usually requires an adequate bone marrow aspiration and biopsy as well as ruling out pernicious anemia (Vitamin B12 deficiency), folic acid deficiency and copper deficiency.

Marrow or blood is examined under light microscopy, as well as flow cytometry, to diagnose the presence of leukemia, to differentiate AML from other types of leukemia (e.g. acute lymphoblastic leukemia - ALL), and to classify the subtype of disease. A sample of marrow or blood is typically also tested for chromosomal abnormalities by routine cytogenetics or fluorescent "in situ" hybridization. Genetic studies may also be performed to look for specific mutations in genes such as "FLT3", nucleophosmin, and "KIT", which may influence the outcome of the disease.

Cytochemical stains on blood and bone marrow smears are helpful in the distinction of AML from ALL, and in subclassification of AML. The combination of a myeloperoxidase or Sudan black stain and a nonspecific esterase stain will provide the desired information in most cases. The myeloperoxidase or Sudan black reactions are most useful in establishing the identity of AML and distinguishing it from ALL. The nonspecific esterase stain is used to identify a monocytic component in AMLs and to distinguish a poorly differentiated monoblastic leukemia from ALL.

The diagnosis and classification of AML can be challenging, and should be performed by a qualified hematopathologist or hematologist. In straightforward cases, the presence of certain morphologic features (such as Auer rods) or specific flow cytometry results can distinguish AML from other leukemias; however, in the absence of such features, diagnosis may be more difficult.

The two most commonly used classification schemata for AML are the older French-American-British (FAB) system and the newer World Health Organization (WHO) system. According to the widely used WHO criteria, the diagnosis of AML is established by demonstrating involvement of more than 20% of the blood and/or bone marrow by leukemic myeloblasts, except in the three best prognosis forms of acute myeloid leukemia with recurrent genetic abnormalities (t(8;21), inv(16), and t(15;17)) in which the presence of the genetic abnormality is diagnostic irrespective of blast percent. The French–American–British (FAB) classification is a bit more stringent, requiring a blast percentage of at least 30% in bone marrow (BM) or peripheral blood (PB) for the diagnosis of AML. AML must be carefully differentiated from "preleukemic" conditions such as myelodysplastic or myeloproliferative syndromes, which are treated differently.

Because acute promyelocytic leukemia (APL) has the highest curability and requires a unique form of treatment, it is important to quickly establish or exclude the diagnosis of this subtype of leukemia. Fluorescent "in situ" hybridization performed on blood or bone marrow is often used for this purpose, as it readily identifies the chromosomal translocation [t(15;17)(q22;q12);] that characterizes APL. There is also a need to molecularly detect the presence of PML/RARA fusion protein, which is an oncogenic product of that translocation.

The WHO 2008 classification of acute myeloid leukemia attempts to be more clinically useful and to produce more meaningful prognostic information than the FAB criteria. Each of the WHO categories contains numerous descriptive subcategories of interest to the hematopathologist and oncologist; however, most of the clinically significant information in the WHO schema is communicated via categorization into one of the subtypes listed below.

The WHO subtypes of AML are:

Acute leukemias of ambiguous lineage (also known as mixed phenotype or biphenotypic acute leukemia) occur when the leukemic cells can not be classified as either myeloid or lymphoid cells, or where both types of cells are present.