Page 484 - Clinical Hematology_ Theory _ Procedures ( PDFDrive )

468 PART 6 ■ Neoplastic Disorders

exist. T e ys unction ppe rs to be loss o regul tory
MASTOCYTOSIS
sign ls th t control the pro uction o ture cells.

M st cells re e ector cells o in tory n llergic re c-

tions. T ese cells secrete v riety o v so ctive n proin- Chronic Myelogenous Leukemia

tory e i tors in their gr nules n high- nity ■ CML is one o the ost co on or s o chronic leu-

IgE-bin ing sites. ke i . T e ise se course is ch r cterize by chronic,

M stocytosis is unique n r re neopl s ef ne by in olent st ge th t requently tr ns or s into ter i-

bnor l exp nsion n ccu ul tion o clon l st cells n l, cute bl st crisis ph se. An cceler te ph se, when

(MCs) in one or ultiple org n syste s such s the skin, p tients beco e re r ctive to tr ition l ther py, y pre-

bone rrow, spleen, n g strointestin l tr ct. ce e the cute ph se.

T e WHO cl ssif c tion o stocytosis is ivi e into ■ T e Phil elphi chro oso e, Ph , w s the f rst berr nt
1
three v ri nts: cut neous n rel te skin lesions, syste ic chro oso e escribe in lign nt isor er. It is the

stocytosis (SM), n loc lize st cell tu ors such s frst e onstr ble he tologic l ch nge in ore th n

ss cell s rco . Syste ic stocytosis involves ulti o- 90% o CML p tients n is present in yelogenous n

c l histologic lesions in the bone rrow n other org ns. erythroi precursors s well s eg k ryocytes. P tients

L bor tory testing y reve l ne i . with CML or cute ly phobl stic leuke i express the

SM is clon l isor er ch r cterize by so tic ut - BCR gene re rr nge ent, which is the olecul r coun-

tion o the c-KI protooncogene. Ste cell ctor receptor is terp rt o the Ph chro oso e.
1
enco e or by c-KI (tyrosine kin se receptor), which is ■ T e clinic l course o CML c n be ch r cterize by three

jor regul tor o st cell evelop ent n he topoietic sep r te progressive ph ses.

ste cells. ■ In CML, the egree o leukocytosis is extre e. CML c n lso

One subgroup o syste ic st cell ise se is st cell be i entif e by the presence o the entire spectru o i -

leuke i , n ggressive leuke i . ture n ture yelogenous cells in the bloo n rrow.

MYELOPROLIFERATIVE NEOPLASM, Chronic Neutrophilic Leukemia and Atypical

UNCLASSIFIABLE (MPN-U) Chronic Myeloid Leukemia

T is c tegory, MPN-U, which y ccount or 10% to 15% ■ Chronic neutrophilic leuke i (CNL) n typic l

o MPN isor ers, c ptures isor ers th t express yelopro- chronic yeloi leuke i ( CML) re r re yeloi leu-

li er tive ch r cteristics but either ils to eet the criteri o ke i s with poor prognosis.

specif c con ition or h s e tures th t overl p with two or ■ Initi lly, bloo s e rs o p tients with CML n CML

ore specif c con itions. y look in istinguish ble bec use both ispl y pro i-

Most c ses o MPN-U ctu lly ll into one o three c t- nent i ture gr nulocytosis-pro yelocytes, yelocytes,

egories: PRV, essenti l thro bocythe i , or PMF. P tients n et yelocytes. However, there re istinct i er-

re in very e rly st ge o ise se in which they o not e - ences between the chronic ph se o CML, CML, n CNL.

onstr te the est blishe criteri or the c tegory or re t

l te st ge o v nce MPN in which extensive yelof bro- Chronic Eosinophilic Leukemias

sis, osteosclerosis, or tr ns or tion to n ggressive st ge A ong the hypereosinophilic syn ro es (HESs), there is

where the true isor er is obscure . ■ continuu o hypereosinophilic ise se. At one o the

P tients cl ssif e s MPN-U l ck Phil elphi chro o- spectru is the eosinophilic yeloproli er tive neopl s ,

so e n BCR-ABL usion gene.
eosinophilic leuke i . At the other en o the spectru

re benign con itions such s p r sitic in ection, sth ,

NOTE: This is a good time to complete end of chapter llergies, or rug hypersensitivity.

Review Questions. ■ PDGFRA- ssoci te chronic eosinophilic leuke i is
r re con ition. T e bone rrow is hypercellul r bec use

o eosinophilic proli er tion n c n exhibit Ch rcot-

Ley en cryst ls.
CHAPTER HIGHLIGHTS
■ New olecul r n i unologic ss ys h ve en ble

General Characteristics and Classi cation ore ef nitive etiologic cl ssif c tions, especi lly those
c ses ssoci te with eosinophilic yeloproli er tive neo-

■ Myeloproli er tive neopl s s re interrel te clon l pl s s. PDGFRA- ssoci te chronic eosinophilic leuke-
bnor lities resulting in n excessive proli er tion o i is c use by ut tions in the PDGFRA gene. As result

v rious phenotypic lly nor l ture cells. o this ut tion, n bnor l protein known s FIP1-like

■ Cl ssif c tions o MPNs inclu e CML, PRV, pri ry 1/pl telet- erive growth ctor lph is synthesize .
yelof brosis, n essenti l thro bocythe i . ■ Chronic eosinophilic leuke i , not otherwise specif e ,

■ No environ ent l c uses o MPNs h ve been i entif e , is clon l yeloproli er tive neopl s th t presents with
but it h s been suggeste th t genetic susceptibility y eosinophili not cl ssif e s nother neopl stic con ition.