Discussion
This large nationwide study showed that a conservative approach is
possible in OMT, with 60% of patients who kept at least one ovary. The
incidence of recurrence was low at 8.3% and was not influenced by the
type of initial surgical approach or the type of tumor resection. Risk
factors for recurrence were intrinsic to the tumor features, such as a
large palpable mass and bilateral synchronous forms at diagnosis.
The clinical presentation of OMT in our series did not differ from the
literature (1, 3, 4, 14), with the most frequent revealing symptom being
abdominal pain in 61% of cases. One-third of patients underwent
emergency surgery and revealed adnexal torsion in 40% of cases, which
represents 25% of the whole cohort. This incidence is relatively high
compared to the 3% to 16% of cases in cohorts including both adults
and children in the literature (6-8, 15, 20, 21). A palpable mass was
present in 27% of cases in our cohort. Data on the exact size of the
lesion was not available for all patients, and the retrospective nature
of our study precludes any analysis of the risk of recurrence according
to tumor size. Nevertheless, the association of a palpable mass with a
risk of recurrence as an independent variable suggests that the size of
the teratoma may influence the risk of recurrence.
Elevations in AFP and HCG are considered features of a malignant GCT,
but in a case of OMT, these tumor markers are usually normal (14, 15).
An elevation in AFP was observed in five cases in our series and may be
related to the presence of a small immature teratoma or a differentiated
liver component (3, 23). This possibility prompts avoidance of any
spillage during teratoma surgery because of the possible association
with an immature component, which was not found at the preoperative
staging.
Our experience showed, as others, that laparoscopy and laparotomy can
both be safely practiced for OMT surgery without any influence on OMT
recurrence (19, 24). Laparoscopy has the advantages of decreasing
postoperative pain, complications, and length of hospitalization (6, 8,
20, 22, 25). It also minimizes postoperative adhesions, which may have
an impact on fertility (6, 7, 24). All of these benefits promote
laparoscopy as the first surgical approach in adults (6, 20, 21).
However, more tumor rupture and spillage are described during
laparoscopy (6, 26), and this risk is increased when OSS is considered.
In our study, laparotomy with or without preceding laparoscopy was
performed in 83% of cases and comprised OSS in 58% of these cases.
Laparoscopy was performed only in 15% of cases, precluding any analysis
of the influence of the type of surgery on the second event in this
group. In the whole cohort, however, OSS did not increase the risk of a
second event. In the literature, unilateral oophorectomy seems to have
no impact on puberty development (27) but could advance menopause by 1.1
to 1.8 years with the health consequences of estrogen deprivation (16,
17, 28, 29). Bilateral forms and second events, reported in 5% and
8.3% of cases in our cohort, may lead to additional amputation of the
ovarian tissue. All these features favor conservative surgery in OMT to
preserve the ovarian tissue and reserve as much as possible (8, 11, 14,
25, 30). In our series, all patients maintained at least one ovary even
after recurrence. Additionally, fertility preservation should be
contemplated in cases of bilateral forms at diagnosis or of a second
event after surgery (31). In this case of benign indications at the
postpubertal stage, oocyte cryopreservation is still the highest-yield
strategy to offer (31). Cryopreservation of ovarian tissue is also an
option and remains the only one before the onset of puberty (31-33).
The incidence of metachronous OMT was 8.3% in our cohort, slightly
lower than the 10 to 20% reported in the literature (6, 8, 17, 19).
Recurrence was observed mainly on the contralateral ovary (62%) or on
both ovaries (10%). The second tumor occurred on the same ovary in only
28% of recurrent cases, an observation already made in other reports
(6, 8, 17). This suggests that metachronous OMT is more a new event than
a local recurrence of the primary tumor. This hypothesis is supported by
DNA profile analysis of OMT at diagnosis and after relapse (34) and PCR
analysis of a case with synchronous bilateral OMT (2). Multiple
synchronous forms and the observation in our study that bilateral forms
are at risk of a second event may suggest a genetic origin in OMT (6).
Data on the presence of a familial history was retrieved in only three
percent of cases in our cohort. This incidence is certainly higher, as
the questioning for familial history is not systematic and information
on this is difficult to retrieve. To date, no specific germinal gene
pathogenic variant background has ever been documented in such families,
as in our cohort (15, 35, 36).
Risk factors for a second event related in our study were also the
occurrence of a perioperative rupture. As most of the recurrences were
on the contralateral ovary, it is difficult to interpret and could be
biased by confounding factors such as the size of the lesion, although
no significant association was observed between perioperative rupture
and palpable mass. Other studies did not find perioperative rupture to
be a risk factor for recurrence in an adult population (7, 37).
As the EFS curve did not show any plateau, it suggests the need for
prolonged surveillance after surgery (18). Considering the median time
to a second event of 30.5 months and the slow growth rate of this benign
tumor, we propose a pelvic and abdominal US exam every 6 months during
the five years following initial surgery. Patients and family should be
informed of the risk of recurrence and of the importance of consulting
in cases of pelvic symptoms. These patients have amputation of their
ovarian capital and may also present adnexal torsion on a functional
cyst or tumor recurrence, even years after the initial event. They must
therefore be considered at risk for premature ovarian failure.
In conclusion, despite the limitations linked to the retrospective
nature of our analysis, these results support a conservative approach
for OMTs in children. The rationale for surgery is the risk of adnexal
torsion and the natural growth of the teratoma, which may preclude any
possibility of OSS (6, 17, 20). In an emergency, laparoscopy is a good
option, particularly when adnexal torsion is observed; simple detorsion
is recommended with a second-step resection surgery. When planned
resection is performed, OSS should be preferred, and laparoscopy should
be considered only if there is no doubt on the benign nature of the
lesion. If this is not the case, TO should be performed preferentially
with a laparotomy preceded by a laparoscopic exploration of the
peritoneum, and peritoneal fluid sending for analysis. Laparoscopy
should be proposed only if the removal of the tumor can be performed
without rupture, avoiding morcellation of the specimen to allow proper
pathological analysis of the tumor (38). Finally, the observation of
multiple bilateral lesions and/or familial history as well as the
contralateral side of most metachronous lesions suggest a genetic
predisposing background and invite wider genetic investigations in
pediatric OMTs.