Invasive breast carcinoma - IARC

Fig. 2.99 Mature cystic teratoma. T1-weighted precontrast
magnetic resonance image. A fat-fluid
level is seen (arrow).
Fig. 2.100 Mature cystic teratoma with dark hair.
The Rokitansky protuberance is composed of fatty
tissue, bone, and teeth protuding into the lumen.
Fig. 2.101 Fetiform teratoma (homunculus). Limb
buds are apparent, and there is abundant hair over
the cephalic portion.
diploid in 90% of cases, whereas most
(66%) of grade 3 tumours are aneuploid
{165,2684}. Similarly, karyotypic abnormalities
are most often seen in grade 3
tumours {165}. Immature teratomas show
fewer DNA copy number changes
detected by comparative genomic
hybridization than other ovarian germ
cell tumours and do not usually exhibit a
gain of 12p or i(12p) {1518,2378}.
Prognosis and predictive factors
The stage and grade of the primary
tumour and the grade of its metastases
are important predictive factors. Prior to
the chemotherapy era, the overall survival
rate of patients with grade 1, 2 and
3 neoplasms was 82%, 63% and 30%,
respectively {2060}.
The use of cisplatin-based combination
chemotherapy has dramatically
improved the survival rate of patients; 90-
100% of those receiving this regimen
remain disease-free {989}.
The tumour grade is a crucial feature that
determines behaviour and type of therapy.
Patients with grade 1 tumours that are
stage IA and those with mature (grade 0)
implants do not re q u i re adjuvant
chemotherapy. Those with grade 2 or 3
tumours, including stage IA, as well as
those with immature implants re q u i re
combination chemotherapy. The management
of patients with grade 1
implants/metastases is not well established.
A recent re p o rt from the Pediatric
Oncology Group concludes that surgery
alone is curative in children and adolescents
with immature teratoma of any
grade, reserving chemotherapy for
cases with relapse {600}. Also, in immature
teratomas occurring in childhood,
the presence of histological foci of yolk
sac tumour rather than the grade of the
immature component, per se, is the only
predictor of recurrence {1174}.
Mature teratoma
Definition
A cystic or, more rarely, a solid tumour
composed exclusively of mature, adulttype
tissues. A cyst lined by mature tissue
resembling the epidermis with its
appendages is clinically designated as
"dermoid cyst". Homunculus or fetiform
teratoma is a rare type of mature, solid
teratoma containing highly organized
structures resembling a malformed fetus
("homunculus" = little man).
Epidemiology
Age
Although most mature cystic teratomas
occur during the reproductive years, they
have a wide age distribution, from 2-80
years (mean, 32), and 5% occur in postmenopausal
women {564}. Mature solid
teratoma occurs mainly in the first two
decades of life {199,2922}.
Incidence
M a t u re cystic teratoma accounts for 27-
44% of all ovarian tumours and up to
58% of the benign tumours {1502}. In
addition to their pure form, derm o i d
cysts are found macroscopically within
25% of immature teratomas and in the
o v a ry contralateral to a malignant primitrive
germ cell tumour in 10-15% of the
cases.
Clinical features
Signs and symptoms
Most mature cystic teratomas present
with a mass, but at least 25% (up to 60%
in some series) are discovered incidentally
{546}. Symptoms such as a pelvic
mass or pain are more common when the
mature teratoma is solid {199,2922}.
The following complications have been
d e s c r i b e d :
(1) Torsion of the pedicle occurs in 10-
16% of the cases, is responsible for acute
abdominal pain and may be complicated
by infarction, perforation or intra-abdominal
haemorrhage.
(2) Tumour rupture occurs in 1% of cases
and can be spontaneous or traumatic.
The spillage of the cyst contents into the
peritoneum produces chemical peritonitis
with granulomatous nodules mimicking
t u b e rculosis or carcinomatosis. Rupture of
m a t u re teratoma containing neuro g l i a l
elements is thought to be responsible for
gliomatosis peritonei characterized by
peritoneal “implants” composed of mature
glial tissue and does not affect the pro g-
nosis {2389}. However, a recent molecular
study has demonstrated that these glial
implants were heterozygous, whereas the
associated mature ovarian teratomas
w e re homozygous at the same micro s a t e l-
lite loci. This finding suggests that glial
implants may arise from metaplasia of
pluripotent müllerian stem cells rather
than from implantation of the associated
ovarian teratomas {845}. Similarly, peritoneal
melanosis characterized by pigmentation
of the peritoneum has been
re p o rted in cases of dermoid cysts.
(3) Infection of the tumour occurs in 1% of
c a s e s .
170 Tumours of the ovary and peritoneum