[Incidence of primary malignant lesions in clinically benign teratoma: on the problem of adequate surgical procedure].

The Problem of an Adequate Surgical Approach: Frequency of malignant teratomas is, according to the literature, 2%-10%. Examining 194 own cases (1983-1993) it was 1.5%. We found one squamous cell carcinoma (0.5%). Additionally we found 2 immature teratomas (1%). We point out the different biological behaviour of malignant mature teratomas and immature teratomas. We agree with the majority of authors that the method of choice is the intact removal of all teratomas without iatrogen rupture or contamination of the abdominal cavity by contents of the teratoma. This adequate surgical procedure can and should be performed by laparotomy or laparoscopy with endobag. The often practised method of cutting open the cyst during laparoscopy, sucking off the contents or cutting the teratoma into pieces, has been proven to lead to implantation and worsening the prognosis in case of a malignant teratoma. Even the rinsing of the abdominal cavity, usually carried out with this method, could not compensate always for the disadvantage of this "dirty" endoscopical method compared with usual oncological standards. This is pointed out by case reports in the literature and the first analysis of a German survey with early-follow-up of 192 laparoscopically managed ovarian malignancies [11a]. The principle of intact removal of every teratoma should again be kept in mind.