Invasive breast carcinoma - IARC

associated with mature teratomas
showed an identical homozygous genotype
for the malignant component and
the mature teratomatous tissues, thus
demonstrating a direct pathogenetic
relationship {683}.
Prognosis and predictive features
The prognosis of squamous cell carcinoma
is poor with a 15-52% overall 5-year
survival and disease related death usually
within 9 months. Vascular invasion is
associated with a high mortality rate
{1214}. Although relatively few cases
have been reported, the prognosis of
adenocarcinoma appears to be similar to
that of squamous cell carcinoma {2970}.
Sarcomas
A
Sarcomas account for 8% of cases of
malignancies in dermoid cysts and are
more often seen in younger patients than
those with squamous cell carc i n o m a .
Cases of leiomyosarcoma, angiosarcoma
{2021}, osteosarcoma {2006}, chond
ro s a rcoma, fibro s a rcoma, rhabd
o m y o s a rcoma and malignant fibro u s
histiocytoma have been reported {2605}.
Melanocytic tumours
Melanomas are rare, occurring much
less commonly than metastatic
melanoma {630}. Overall, one-half of the
patients with stage I dermoid-associated
melanoma are alive at 2 years {404}.
Melanocytic naevi of various types may
arise within a typical dermoid cyst
{1544}.
Sebaceous tumours
Sebaceous tumours are specialized neoplasms
arising within an ovarian dermoid
cyst that resemble various forms of cutaneous
sebaceous gland tumours (sebaceous
adenoma, basal cell carcinoma
with sebaceous diff e rentiation, sebaceous
carcinoma). The hallmark of these
lesions is the presence of large numbers
of mature, foamy or bubbly sebaceous
cells that stain positively with oil red O in
a tumour arising within a dermoid cyst
{491}.
Pituitary-type tumours
Corticotroph cell adenoma and prolactinoma,
respectively responsible for
B
Fig. 2.109 Ependymoma of the ovary. A The tumour cells have uniform nuclei and form two rosettes. B Many
tumour cells are strongly positive for glial fibrillary acidic protein with accentuated staining around the
rosettes.
Cushing syndrome and hyperprolactinema
with amenorrhea, may arise within a
typical dermoid cyst and have a benign
clinical course {143,1389,2162}.
Retinal anlage tumours
Pigmented progonoma and malignant
tumours derived from retinal anlage within
ovarian teratomas have macroscopically
pigmented areas that correspond to
solid nests, tubules and papillae composed
of atypical cells with melanin-containing
cytoplasm {1112,1466,2712}.
Other monodermal teratomas and
related tumours
Neural cyst of the ovary lined by a single
layer of ependymal cells with white matter,
astrocytes and reactive glia in the
underlying wall corresponds to a monodermal
teratoma with unidirectional neurogenic
diff e rentiation {894}. Similarly,
endodermal variants of mature teratoma
lined exclusively by respiratory epithelium
{508} and ovarian epidermoid cysts
{823} may fall into the category of monodermal
teratoma.
Mucinous cystadenomas arising within
mature teratomas have a homozygous
teratomatous genotype, supporting their
g e rm cell origin {1731}. Mesoderm a l
derived tumours such as lipoma composed
of mature adipocytes with scattered
benign sweat glands may occur
{961}. Glomus tumour may rarely arise
within a typical dermoid cyst {2682}.
Germ cell tumours 175