Placental Site Trophoblastic Tumour and EpitheloidTrophoblastic Tumour in a Group of MalignantTumours of the Trophoblast Recorded in the Centre forTrophoblastic Disease in the Czech Republic in1955-2000

Overview

Objective:
To establish the role of Placental Site Trophoblastic Tumour (PSTT) and so calledEpitheloid Trophoblastic Tumour (ETT) among malignant trophoblastic tumours (MTT).Design of the study: Retrospective analysis.Setting: Trophoblastic Disease Centre (TDC-CZ) in the Czech Rep., Institute of Mother and ChildCare (UPMD), Prague 4.Methods: Clinical pathologic analysis of 367 malignant trophoblastic tumours (MTT) was perfor-med during the years 1955 to 2000. All cases were diagnosed, evaluated and treated in the TDC-CZ in the Czech Rep.Results: Based on the comparison of development stages of orthologic trophoblast 5 types of MTTwere introduced: 1. typical „classical“ choriocarcinoma (CH), so called No Special Type (CH-NST), 2. CH-syntiotrophoblastic (CH-SYN), 3. CH-cytotrophoblastic (CH-CYT), 4. CH-dissociated(CH-DIS), 5. Ch-undifferentiated (CH-UND).Malignant types of PSTT are morphologically identical with CH-CYT and CH-DIS, ETT correlateswith CH-UND. The occurrence of all types of CH is presented in relation to different treatmentstrategy in three periods of time: 1. period (1955-1963) without chemotherapy (CHT), 2. period(1964-1980) undifferentiated CHT, 3. period (1981-2000) differentiated chemotherapy - treatmentprotocols.During the whole period CH-NST was detected 294x, and represented 80,1% of all MTT. CH-SYNwas diagnosed 14x i.e. 3,8%, CH-CYT in 12 cases, i.e. 3,3%, CH-DIS in 22 cases, i.e. 6% and CH-UNDwas diagnosed 25x, i.e. 6,8%.During all three periods the number of MTT was nearly the same but the mortality has changeddramatically. In the first period mortality presented 94,5% in all types, in the second periodmortality dropped to 43,6% and in the third period to 5,8%. Significant differences in mortalitywere due to histological type. In CH-NST mortality represented only 3,2% and in highly differenti-ated type CH-SYN it was 0%. On the other hand mortality in poorly differentiated types repre-sented in CH-CYT 40%, in CH-UND 18,1%, in CH-DIS 11,1%.Lethality of PSTT comprises the mortality of CH-CYT and CH-DIS together and in the first periodrepresented 100%, in the second period it dropper to 53,8% and in the third period to 21,4%.Mortality on ETT correlating to CH-UND comprised in the first period 100%, in the second period44,4% and in the third period 18,1%.-due to aggressive polychemotherapy and early surgicalintervention.Conclusion: Presented morphologic characteristic makes routine bioptic diagnosis of malignanttypes of PSTT and ETT possible as well as their differentiation from benign trophoblastic lesion.These tumours - PSTT and ETT-belong to poorly differentiated MTT.

Key words:
Placental Site Trophoblastic Tumour, Epitheloid Trophoblastic Tumour, mortality on