Irritable Larynx Syndrome (ILS)(Morrison, Rammage & Emami, 1999) has as its central thesis the idea that we can develop neuroplastic changes in the brain when a threshold of tolerance to an irritation in the upper airway or larynx is passed, creating conditions which may include chronic cough and paradoxical vocal fold motion (PVFM).
This model is appealing for patients who have been told by health care providers, likely out of frustration, that they should "just quit coughing" or "just breathe." It is helpful to consider that perhaps it isn’t in the …
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The association between Down syndrome and acute myelogenous leukemia (AML) has been well documented.1,2,3 AML in Down syndrome is usually a specific type of megakaryoblastic leukemia (M7, AMKL).1 A myelodysplastic syndrome generally precedes this malignancy. Down syndrome patients with AMKL have a much better prognosis than other children with AML.5
A case study of a 22-month-old female with Down syndrome and myelodysplastic syndrome of a megakaryoblastic lineage is presented here. Upon admission to a pediatric hematology/oncology clinic, flow cytometry results reported a distinct population of phenotypically abnormal myeloblasts expressing myeloid antigens and the immature cell markers.
The patient was placed on a national research group study and began chemotherapy treatment. To date she has received two courses of cytarabine (ara-c) and daunorubicin therapy, which were tolerated well, and is awaiting her third course. Her blood counts stabilize for a while after treatments and her prognosis is good.
ABBREVATIONS: AMKL = acute megakaryoblastic leukemia; AML = acute myelogenous leukemia; BMT= bone marrow transplant; CBC = complete blood count; CMV = cytomegalovirus; RSV = respiratory syncytial virus; TAM = transient abnormal myelopoiesis.
INDEX TERMS: acute megakaryoblastic leukemia (M7, AMKL); acute myelogenous leukemia (AML); Down syndrome.
Clin Lab Sci 2006;19(3):161
The association between Down syndrome and AML has been well documented for nearly 70 years.1′2′3 Children with Down syndrome have a tenfold to 20-fold increased risk of developing AML over those who do not carry the extra chromosome 21.2 It is estimated that about two percent of children presenting with pediatric leukemia have Down syndrome.4 AML in Down syndrome is usually a specific type of acute megakaryoblastic leukemia (M7, AMKL).1 AMKL is very rare in the general population. A myelodysplastic syndrome generally precedes this malignancy. Myelodysplastic syndrome is a disease in which the bone marrow does not function normally and is sometimes referred to as preleukemia or “smoldering leukemia”. Chances are high for a Down syndrome patient with myelodysplastic syndrome to differentiate into AMKL.1
CASE PRESENTATION
The patient is a 22-month-old white female with Down syndrome. She appeared to be in a normal state of health with a past medical history of asthma and respiratory syncytial virus (RSV) for which she was being treated with Pulmicort and Xopenex nebulizers when needed. At birth, she was an uncomplicated 37 week delivery with a negative echocardiogram. She lives at home with her mother, father, and three year old sister. There are no sick contacts at home, and she does not attend daycare. She was taken to her local physician after her mother noticed that she was pale with decreased activity and seemed to be easily fatigued. A complete blood count (CBC) reported a white blood cell count of 5400/uL, hemoglobin 4.2g/dL, hematocrit 12.4%, and a platelet count of 8000/uL. A differential showed a predominance of lymphocytes and a few blasts. She was promptly referred to a pediatric hematology/oncology clinic for myelodysplasia with severe anemia and thrombocytopenia.
At the pediatrie oncology clinic a physical examination revealed a positive umbilical hernia and pinpoint petechia on her lower extremities and left forearm. All other vital signs proved unremarkable. She then received transfusions of packed red blood cells and platelets. The peripheral blood smear revealed a predominance of small, mature lymphocytes. There were a few blasts with round to oval nuclei, partially condensed chromatin, several tiny prominent nucleoli, and blue cytoplasm. Only occasional platelets were seen. The red cell morphology showed anisocytosis, poikilocytosis with occasional teardrop cells, spherocytes, ovalocytes, and a few schistocytes. There were also several mononuclear cells with oval nuclei, blue cytoplasm, and irregularities in shape that appeared to be monocytes. Her CBC and differential results from the pediatrie hematology/oncology laboratory are shown in Table 1.
A battery of tests ensued including bone marrow biopsies taken from the right and left posterior iliac spine. The biopsies were reviewed using para-aminosalicylic acid and haematoxylin and eosin stains. Marked megakaryocytic hyperplasia and reticulin fibrosis were noted along with marked erythroid and myeloid hypoplasia. Small lymphoid aggregates were also seen. Reticulin fibrosis is common in AMKL.
Cytogenetic studies were also performed. Chromosome analysis from cultured bone marrow cells revealed the presence of an abnormal, mosaic pattern consistent with a neoplastic process. Using Giemsa banding techniques, 20 metaphase cells were examined and all of them contained an extra chromosome 21 (trisomy 21). In addition, seven of the 20 cells contained an additional isochromosome 8q resulting in an 8q tetrasomy. The trisomy 21 is a constitutional abnormality because the patient was already known to have Down syndrome. Isochromosome 8q is not known to be diagnostic of any specific neoplasia but is probably the result of some dysplastic event occurring in the bone marrow.
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