Transition of endometrial stromal sarcoma into high-grade sarcoma.
BACKGROUND
Endometrial stromal sarcoma typically is of low grade and hormone-sensitive. Although these characteristics result in an indolent behavior, little data are available on the evolution over time.


METHODS
We report on two cases where microscopic and immunohistochemic assessment of the tumor on several occasions during 8 and 25 years of follow up enabled us to document a transition of a low-grade into a high-grade malignancy. These were mainly characterized by increased cellular atypia, absence of spiral arterioles and an increased mitotic index and proliferation index (MIB1). Since this transition was related to clinical loss of hormone sensitivity, the therapeutic approach consisting of hormonal treatment in combination with repetitive surgery was switched to chemotherapy only.


CONCLUSIONS
These long-term follow up data provide insight in endometrial stromal sarcoma tumor biology and highlight the importance of sampling recurrent tumors to estimate biologic behavior in order to tailor subsequent treatment.
Amant
Frederic
F
Division of Gynecological Oncology, Department of Obstetrics and Gynecology, UZ Gasthuisberg, Katholieke Universiteit Leuven, Herestraat 49, 3000 Leuven, Belgium. Frederic.amant@uz.kuleuven.ac.be
Woestenborghs
Heidi
H
Vandenbroucke
Vanessa
V
Berteloot
Patrick
P
Neven
Patrick
P
Moerman
Philippe
P
Vergote
Ignace
I
D000328:Adult; D002471:Cell Transformation, Neoplastic; D003131:Combined Modality Therapy; D003937:Diagnosis, Differential; D016889:Endometrial Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D005260:Female; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D018203:Sarcoma, Endometrial Stromal / Q000175:diagnosis* / Q000473:pathology / Q000628:therapy; D017154:Stromal Cells