the myelodysplastic syndromes ( mds ) are characterized by proliferation of hematopoietic stem cells with abnormalities of differentiation leading to peripheral blood cytopenia and a preleukemic state .
the mechanism of transformation of mds to acute myeloid leukemia ( aml ) includes many factors , and prediction of the transformation is not yet clear .
we report a case of leukemic transformation of mds with multi - muscle involvement and whole - body 2-[f18 ] fluoro-2-deoxy - d - glucose positron emission tomography ( f18-fdg pet ) .
a 52-year - old female , presenting with high fever for 10 days , chills , frequent micturition , and urgency , was admitted to the regional hospital on 10 april 2009 .
were given , and after a week , she was relieved of the above - mentioned symptoms .
blood counts showed moderate pancytopenia ( hemoglobin 92 g / l , wbc 1.57  10/l and platelets 92  10/l ) . on 20 , 22 and 27
april , bone marrow aspiration biopsy was performed repeatedly , and the percentage of blast cells from bone marrow was 12.55% , 22.5% , and 26.5% , respectively .
on 20 april , flow cytology detected 13.50% blast cells from bone marrow , which had cd34 , cd2 , and cd41phenotype , and bone marrow biopsy microscopically revealed that granulocyte and megakaryocyte series reduced , and a fraction of plasma cells diffusing encroached that were mpo , cd38 , cd138 , cd68 , cd61 , cd3 , cd45ro , cd20 , cd79a .
however , 4.49% blast cells were detected that had cd34 , cd2 , cd7 , cd117 , cd71 , hla - drphenotype on 27 april , and it microscopically disclosed scattering immature mononuclear cells which were mpo , cd68 , and cd61 .
therefore , f18-fdg pet of whole body was carried out on 5 may , which manifested no evidence of malignancy , including that of bone marrow [ figure 1 ] .
the final diagnosis could not be made because of the patient 's resolution to give up treatment .
she was intermittently transfused blood without any other treatment for about 10 months since she had been discharged . on 25 march
, she was hospitalized with fever of 3 days duration accompanied by swelling and pain of the right upper leg and stern . on physical examination
routine blood analysis showed serious pancytopenia ( hemoglobin 81 g / l , wbc 0.67  10/l , platelets 35  10/l ) .
bone marrow aspiration displayed that immature monocytes accounted for 25.0% , periodic acid - schiff stain ( pas ) ( + ) , peroxidase stain ( pox ) ( + ) , considering aml .
flow cytometry detected 28.60% blast cells , which had cd34 , cd13 , cd64 , cd11b , hla - dr phenotype , from bone marrow .
whole - body lymphoimaging showed that lymph fluid circulation was unobstructed and soft tissues of the right lower limb were swollen [ figure 2 ] .
f18-fdg pet of whole body showed spotted and focal increased uptake in ribs , vertebrae , ilium , humerus , femur , tibia , and high intensity foci of fdg uptake in right axillary , mediastinal , bilaterally lung portal , peritoneal , right communistic and external iliac lymph nodes .
moreover , a significant lesion of increased metabolism infiltrated muscles of right rear upper legs , right gluteus maximus and medius [ figure 3 ] . according to the above outcomes and physical examination , the final diagnosis was inclined to be aml . as a result , treatment with cag chemotherapy regimen was started . during the course of chemotherapy , intumescence of right upper leg and stern conspicuously lessened . however , after less than a week , the patient died from cerebral hemorrhage and hernia .
f18-fdg pet manifests no evidence of malignancy , including that of bone marrow whole - body lymphoimaging shows easy and smooth lymph fluid circulation and lymph node enlargement f18-fdg pet demonstrates focal increased uptake in ribs , vertebrae , ilium , humerus , femur , tibia , and high intensity foci of fdg uptake in right axillary , mediastinal , bilaterally lung portal , peritoneal , right communistic and external iliac lymph nodes .
moreover , a chunk of lesion of increased metabolism infiltrated the muscles of right rear upper legs , right gluteus maximus and medius
the case reported here was that of an old woman presenting with pancytopenia , chromosome clonal abnormality , fluctuation of the percent of blast cells at 20% , and negative evidence of malignancy in whole - body f18-fdg pet .
after about 10 months , the blast cells accounted for about 25% , the morphology of which was similar to that of the previous ones , and f18-fdg pet demonstrated diffusing increased uptake in the right upper leg and lymph nodes , and patchy high uptake of bone marrow . in this case , the main differential diagnosis of pancytopenia was between leukemia and mds .
the percent of blast cells of bone marrow is critical to differentiate leukemia and mds . in this patient , retrospectively , it is speculated that it was the transformation from mds to aml in april 2009 , which might have led to inconsistent bone biopsies , aspirations and immunophenotypes .
immunophenotyping demonstrated that blast cells were of myeloid lineage , which is consistent with the earlier reports.[13 ] therefore , close follow - up was recommended . to the best of our knowledge
, few studies about multi - muscle of leg involvement have been reported , and obviously the diagnostic value of f18-fdg pet in the fields of mds and aml has been attributed to reduced f18-fdg pet uptake in the bone marrow . it was reported that f18-fdg pet performed in a patient with mds showed diffusing increased uptake of bone marrow of the whole body , which transformed into aml after 2 months , showing that f18-fdg pet may be an indicator for transformation of mds to aml . in this case , f18-fdg pet detected tumor burden and was positive for extramedullary infiltration in aml phase , which is compatible with the previous reports , but was negative for malignancy of bone marrow in the state of transformation phase , which is not concordant with the previous reports .
agool and others[68 ] reported that homogeneous increased uptake of bone marrow was seen in eight mds patients in 3-deoxy-3-[f18]-fluorothymidine positron emission tomography ( f18-flt pet ) , which , in comparison to f18-fdg pet , is more related to the rate of dna synthesis and cycling activity and provides visual and quantitative information on the entire bone marrow compartment .
perhaps it is more sensitive than f18-fdg pet in forecasting transformation of mds to aml .
the value of f18-fdg or f18-flt pet as an indicator in predicting the transformation of mds to aml needs to be explored in the future , and f18-fdg or f18-flt pet can reflect extramedullary infiltration and bone marrow cellularity of whole body , compared with invasive , regional biopsies and aspirations .
 the case reported here was that of an old woman characterized by pancytopenia , chromosome clonal abnormality , fluctuation of the percent of blast cells at 20% , and negative evidence of malignancy in whole - body 2-[f18 ] fluoro-2-deoxy - d - glucose positron emission tomography ( f18-fdg pet ) . 
 after about 10 months , the blast cells accounted for about 25% , the morphology of which was similar to that of previous ones , and f18-fdg pet demonstrated diffusing increased uptake in the right upper leg and lymph nodes and patchy high uptake of bone marrow . 
 2-[f18]-fluoro-2-deoxyglucose can reflect extramedullary infiltration and bone marrow cellularity of the whole body , compared with invasive , regional biopsies and aspirations . 
 the value of 2-[f18]-fluoro-2-deoxyglucose or 3-deoxy-3-[f18]-fluorothymidine positron emission tomography as an indicator in predicting the transformation of myelodysplastic syndrome to acute myeloid leukemia needs to be explored in the future . 
INTRODUCTION
CASE REPORT
DISCUSSION