Cytodiagnosis of placental site trophoblastic tumor. A report of two cases.
BACKGROUND
Placental site trophoblastic tumor (PSTT) is a rare form of trophoblastic neoplasm. Approximately 100 cases of PSTT have been reported, but we found no report on its cytodiagnosis.


METHODS
Case 1, a 39-year-old female, came to the hospital because of abnormal genital bleeding. Case 2, a 36-year-old female came because of amenorrhea for a year. In both cases, endometrial smear and intrauterine curettage suggested trophoblastic disease, and hysterectomy was performed. Laboratory data revealed a mild increase in human chorionic gonadotropin (hCG) and beta-hCG but normal human placental lactogen (hPL). In the cytologic examination, the background contained some hemorrhagic and fibrinous areas but no necrosis. Most tumor cells stained light green, were round or polygonal, and contained abundant cytoplasm. Some were palely stained and had vacuoles. Some cells showed hyperchromatism, an irregular nucleus, fine-to-coarse chromatin granules and markedly different sizes. Most of the cells were hPL positive, and a few were hCG positive.


CONCLUSIONS
Both cases were considered benign because of rare mitoses despite cellular pleomorphism. However, careful follow-up is required. The differential diagnosis of PSTT is difficult from cytologic and biopsy specimens alone but may be achieved with additional magnetic resonance imaging findings and positive staining of hPL and hCG.
Ishi
K
K
Department of Clinical Laboratory, Juntendo University Urayasu Hospital, Japan.
Suzuki
F
F
Saito
A
A
Koyatsu
J
J
Akutsu
S
S
Kubota
T
T
D000328:Adult; D000568:Amenorrhea / Q000209:etiology; D014408:Biomarkers, Tumor / Q000032:analysis; D002455:Cell Division; D002822:Choriocarcinoma / Q000175:diagnosis; D006063:Chorionic Gonadotropin / Q000032:analysis; D003937:Diagnosis, Differential; D054278:Embryonal Carcinoma Stem Cells; D005260:Female; D006801:Humans; D007890:Leiomyosarcoma / Q000175:diagnosis; D008279:Magnetic Resonance Imaging; D009363:Neoplasm Proteins / Q000032:analysis; D014411:Neoplastic Stem Cells / Q000648:ultrastructure; D010920:Placenta / Q000473:pathology*; D010928:Placental Lactogen / Q000032:analysis; D011247:Pregnancy; D014328:Trophoblastic Neoplasms / Q000737:chemistry / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D014592:Uterine Hemorrhage / Q000209:etiology; D014594:Uterine Neoplasms / Q000737:chemistry / Q000150:complications / Q000175:diagnosis* / Q000473:pathology
D014408:Biomarkers, Tumor; D006063:Chorionic Gonadotropin; D009363:Neoplasm Proteins; D010928:Placental Lactogen