Since our publication, which first defined the malignant potential of
placental site trophoblastic tumor (PSTT), we have had a keen interest
in this rare, unique entity. This histologic entity is noted by its m
onomorphic population of trophoblast-like cells which are classified a
s originating in the intermediate trophoblast. These cells contain hym
man placental lactogen (HPL). This is in contrast to cytotrophoblastic
and syncytiotrophblastic tissues as the histologic, cytologic and inm
unohistochemical stain characteristics are disparate. Its rarity and t
he wide spectrum of clinical behavior combined with the lack of sensit
ivity of serum levels of beta hCG in predicting disease recurrence and
spread have lead to anecdotal reports outlining clinical management.
Most discerning to the clinician is the high mortality of metastatic p
lacental site trophoblastic tumor. At our institution, we have treated
two patients with a metastatic disease with a successful conclusion.
The durability of responses is 3 and 8 years. This report will present
these patients in detail and define the important characteristics of
successful treatment. The use of dose-intensive, multi-agent chemother
apy, early intervention when metastatic disease is discovered, imaging
techniques to define disease spread, surgery fur localized disease an
d the use of growth factors, most notably granulocyte colony-stimulati
ng factor (G-CSF), are the fundamentals of clinical care of placental
site trophoblastic tumor in patients with metastatic placental site tr
ophoblastic tumor.