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Sir,
The terminology and classification of Gestational Trophoblastic Disease (GTD) for its management is the topic of intense controversy and confusion, not only among undergraduates and postgraduates, but also among the faculty who are practicing gynaecologic oncology.
Thank you for the excellent review on classification of GTD with a critical analysis of each classification system in Obstetrics and Gynecology Communications 1999;3:15-22.
It has been emphasised clearly in the article that histopathology is not essential for diagnosis of choriocarcinoma. It is not surprising to see many faculty waiting for histopathology of uterine curettings before starting chemotherapy, instead of using sensitive b-hCG values. Trophoblastic tumours are a unique exception to the rule that histologic diagnosis of neoplasm is essential. The drawback of histopathology is that the cells of normal trophoblast at the placental site have been erroneously diagnosed as choriocarcinoma.1 Because of the similarity to early trophoblast in normal pregnancy, caution is needed in making the diagnosis based on barely sufficient uterine curretings. Failure to find any trophoblast on curettings from the endometrium does not exclude the presence of malignant trophoblast invading into the myometrium.
As suggested in this review there should be clear guidelines for metastatic survey of gestational trophoblastic tumour (GTT) to assign each patient to the particular risk score. The central nervous system is the second commonest site of metastasis in the high-risk group.2 Nearly all patients who have lung deposits have central nervous system metastases.3 Ideally, therefore, all patients with lung metastases should be evaluated for
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central nervous system metastases, either with computerised tomography (CT) scan or magnetic resonance imaging (MRI).
It has been clearly highlighted in this review that the World Health Organisation (WHO) prognostic scoring system is unclear on whether lung metastases should be included in the total number of metastases. Similarly, I would like to add that in the category of largest tumour, including the uterine, it is not very clear whether to include lung metastases for measuring the size of the largest tumour. Regarding ABO grouping in the WHO scoring system, it is suggested that it can be removed from the scoring system, because it is difficult for any centre to have complete data on both patients and the relevant partner.4
Liver metastases in GTT are a more powerful adverse risk factor than brain metastases. Hence, this anatomic site should be assigned a score of 4 or 6 instead of a score of 2 in the WHO scoring system.5 An interesting observation in a recent review of the literature4 was that the scores assigned in the WHO scoring system were 1, 2, and 3, instead of 0, 1, 2, 4, or 6.
An important practical point that has been brought out in this review is tumour-related surgery as a high risk factor. This group of patients does, however, have a greater tendency to relapse after stopping treatment. Finally, the National Institute of
Correspondence to:
Dr A P Manjunath. MD
Assistant Professor
Dept of Obstetrics and Gynecology
Kasturba Medical College and Hospital
Manipal - 576 119, Karnataka, India
Fax: 08252-70061,70062
E-mail:
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A P Manjunath
Manipal |
