In the past, a lymphangiogram or surgical laparotomy (which involves opening the abdominal cavity and visually inspecting for tumors) were performed. Lymphangiograms or laparotomies are very rarely performed, having been supplanted by improvements in imaging with the CT scan and PET scan.On the basis of this staging, the person will be classified according to a staging classification (the Ann Arbor staging classification scheme is a common one):
Stage I is involvement of a single lymph node region (I) (mostly the cervical region) or single extralymphatic site (Ie);
Stage II is involvement of two or more lymph node regions on the same side of the diaphragm (II) or of one lymph node region and a contiguous extralymphatic site (IIe);
Stage III is involvement of lymph node regions on both sides of the diaphragm, which may include the spleen (IIIs) or limited contiguous extralymphatic organ or site (IIIe, IIIes);
Stage IV is disseminated involvement of one or more extralymphatic organs.The absence of systemic symptoms is signified by adding "A" to the stage; the presence of systemic symptoms is signified by adding "B" to the stage. For localised extranodal extension from mass of nodes that does not advance the stage, subscript "E" is added. Splenic involvement is signified by adding "S" to the stage. The inclusion of "bulky disease" is signified by "X". Pathology
MacroscopyAffected lymph nodes (most often, laterocervical lymph nodes) are enlarged, but their shape is preserved because the capsule is not invaded. Usually, the cut surface is white-grey and uniform; in some histological subtypes (e.g.
Other less frequent signs and symptoms consist of anaemia, fever, weight loss, night sweats, infection, bleeding, synovitis, lymphadenopathy, skin rashes, pleural effusion, pericardial effusion and peritoneal effusion. Cause
Although the cause of CMML is unknown, environmental carcinogens, ionising radiation and cytotoxic agents may have a role in causing disease. Approximately one third of cases of MDS with a monocyte count of >10% and <1x109/L will progress to CMML. Pathogenesis
With a high rate of Ras mutation in CMML, deregulation of this signalling pathway has been linked to the pathogenesis of the disease. Tumour necrosis factor, GM-CSF, interleukin-3, interleukin-4, interleukin-6, and interleukin-10 may have a role in hyperproliferative CMML cells. These cytokines can stimulate the growth of CMML in vitro. Hypermethylation of cytosine residues (usually in the promoter regions of genes) occurs in many malignancies to regulate gene expression. One commonly hypermethylated gene in CMML is p15INK4b, a gene involved in cell cycle regulation. Genetic mutations
Clonal genetic abnormalities are common in CMML but they are not specific for diagnosis of the disease. The most common found are the 8+, −7/del (7q) and structural 12p abnormalities. KRAS and NRAS are mutated in 25–40% of the cases of CMML. The Jak2 V617F mutation is found in 10% of cases. Mutations in transcription factors such as RUNX1, CEBPA, NPM1 and WT1 have been found in up to 30% of cases. Mutations of CBL are found in approximately 5–18% of cases. Mutations in the TET2 gene are found in approximately 40–50% of CMML.