Page 494 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

478 PART 6 ■ Neoplastic Disorders

the subsequent evelop ent o AML. P tients with long- Chil ren with pri ry MDSs c n h ve clinic l n

r eletion o chro oso e 20 (20q-) usu lly h ve intr c- l bor tory e tures o juvenile chronic yeloi leuke i .

t ble yspl stic syn ro es, n ny progress to leuke i . So e pe i tric p tients coul be consi ere to h ve either

Although e novo n secon ry MDSs sh re cert in the onoso y 7 syn ro e or juvenile chronic yeloi leu-

clinic l n cytogenetic e tures, ore th n 20% o p tients ke i , in ic ting th t these two entities re not utu lly

with e novo MDS h ve nor l k ryotype, n ne rly ll exclusive. In these p tients, bnor l requencies o he -

these p tients survive beyon 5 ye rs. In contr st, secon - topoietic progenitors or i erenti tion p tterns in culture

ry MDS is requently ssoci te with clon l chro oso e or both c n occur. Abnor lities o en ect the erythroi

bnor lities, n overt leuke i gener lly occurs within 1 n the gr nulopoietic line ges, pre o in ntly bnor l-

ye r. ppe ring croph ge colonies. Clinic l outco es re poor,

with r pi tr ns or tion to AML in ost p tients.

Clinical Signs and Symptoms Sum m ary of Cell Line Abnorm alities

A history o in ections, blee ing, weight loss, or c r iov s- Erythrocyte Abnorm alities

cul r sy pto s y be reporte by p tient. In ections re Erythroi bnor lities o bloo n bone rrow re

c use by ys unction l gr nulocytic neutrophils or bso- co on bec use MDS is o in te by ine ective he to-

lute gr nulocytopeni . He orrh ges c n occur bec use o poiesis. Isl n s o erythroi hyperpl si with erythrobl stic

ecre se or ys unction l pl telets. Ane i is co on e or ities c n be seen in the bone rrow. T e eg lo-

initi l presenting sy pto . A p ucity o other physic l bl stic ch nges (e.g., nucle r-cytopl s ic yssynchrony)

sy pto s is usu lly present. o en re si il r to those o nutrition l eg lobl stic ne-

Neutrophilic er tosis h s occurre occ sion lly in i s. Erythrobl sts (rubribl sts) y be ultinucle te ,

MDS p tients. In these p tients, biopsy speci ens o skin r g ente , or issh pe . Abnor l nucle r sh pes inclu e

lesions showe signif c nt inf ltr tion by neutrophils with in ent tions, lobes, or n irregul r outline. Cytopl s ic

nucle r no lies, th t is, hyposeg ent tion (pseu o– st ining is o en uneven, n the cell rgins y be r gge

Pelger-Huët no ly) or hyperseg ent tion. or in istinct n y ispl y punct te b sophilic stippling.

About one ourth o p tients with RA e onstr te ring

Laboratory Manifestations si erobl sts si il r to those o si erobl stic ne i s in the

bone rrow. Ring si erobl sts re sc rce in eg lobl stic
Cellular Abnorm alities ne i s. P tients with RARS usu lly present with u l

Ane i , low pl telet count, n low tot l leukocyte count, popul tion o re cells: inor one th t is hypochro ic

usu lly with n bsolute neutropeni , re co only pres- n icrocytic, o en ispl ying b sophilic stippling, n

ent ( ble 24.3). Peripher l bloo s e rs requently exhibit jor one th t is crocytic with high e n corpuscul r

re bloo cell (RBC) bnor lities n l rge ys unction l volu e n eg lobl stoi ch nges. An occ sion l nucle-

pl telets. MDS is ch r cteristic lly ni este by p ncyto- te RBC y be seen in the peripher l bloo .

peni in the peripher l bloo , yspl si o two or three cell

lines th t y initi lly be in just one cell line, n low leu- Leukocyte Abnorm alities

ke ic bl st count in the bone rrow n peripher l bloo . Abnor lities o the yeloi series re gener lly ore subtle

P ncytopeni occurs in ore th n 50% o p tients. th n those o yserythropoiesis. Neutrophils re o en gr n-

So e c tegoric l ch r cteristics o MDS types re over- ul r or hypogr nul r. Precursor rrow yelocytes y

l pping. T e he topoietic isor ers constituting MDSs lso l ck secon ry gr nules. A ense ri o b sophili y

lso sh re so e co on e tures with the e rly ph ses o occur t the cell periphery. Pri ry gr nules y be bsent

yeloproli er tive ise ses, especi lly AML. However, the ro pro yelocytes.

bone rrow o ny p ncytopenic p tients y reve l Myelocytes n pro yelocytes c n h ve centr l, roun

cute leuke i , e novo or ro other c uses, inclu ing nuclei. Nucle r no lies inclu e the pseu o–Pelger-Huët

MDS. In ition, p ncytopeni y represent n pl stic no ly n the twinning e or ity. T e twinning e or-

ne i . Distinguishing between MDS n pl stic ne i ity involves two iscrete seg ente str n s in tetr -

c n be i cult, bec use both o these isor ers c n h ve ploi cell, which lso pro uces n bnor lly l rge cell.

si il r clinic l n orphologic l e tures (see Ch pter 13 Hyperseg ent tion y lso be seen. Peripher l bloo n

or iscussion o pl stic ne i ). MDS ust lso be bone rrow neutrophils h ve si il r no lies.

i erenti te ro secon ry ne i s (e.g., vit in B Low ly phocyte counts in bone rrow c n be observe .
12
ef ciency). A signif c nt ecre se o CD3- ef ne p n ly phocytes in

P tients with ggressive subtypes o MDSs (i.e., RAEB) peripher l bloo c n be exhibite . T is re uction is pri r-

requently h ve thro bocytopeni n neutropeni , n ily conf ne to the CD4- ef ne helper subset, but there c n

their rrow e onstr tes ys eg k ryocytopoiesis n be rel tive incre se in the CD8- ef ne suppressor sub-

ysgr nulocytopoiesis s co p re to the ore benign sub- popul tion. As result, the r tio o CD4-CD8 ly phocytes

types (i.e., RA n RARS). In ition, leuke ic tr ns or - is reverse . Consequently, bnor lities o cell- e i te

tion ost requently co es ro the ggressive subtypes. i unity unction c n occur.