Invasive breast carcinoma - IARC

c a rcinomas are difficult to diagnose
since struma ovarii generally lacks a
capsule and has irregular margins. The
thyroid tissue of struma may be uniformly
malignant in some cases, undoubtedly
arising in such cases from histological
foci of normal-appearing thyroid tissue,
which are not extensive enough in itself
to qualify for the diagnosis of struma
ovarii.
Fig. 2.104 Genetic analysis of various histological components selectively microdissected from a mature
ovarian teratoma using microsatellite markers INT-2 (11q13) and D95303 (99). Teratomatous components
are homozygous showing one allelic band, whereas lymphocytes associated with squamous and respiratory
epithelium are heterozygous with both allelic bands, similar to host tissue (normal ovarian stroma).
malignant struma ovarii re p re s e n t i n g
0.01% of all ovarian tumours and 5-10%
of all struma ovarii. Most patients are in
their fifth decade {3146}.
Clinical features
Signs and symptoms
Patients present with a palpable abdominal
mass or unusual symptoms including
Meigs syndrome {983}, cervical thyroid
hypertrophy and thyrotoxicosis (5% of
cases) with high pelvic iodine uptake
{2697}. An elevated serum level of thyroglobulin
occurs in malignant struma
ovarii {2412}.
Macroscopy
The tumour is unilateral and varies from
0.5-10 cm in diameter. It has a brown
solid and gelatinous sectioned surface
and sometimes appears as a nodule
within a dermoid cyst. Entirely cystic strumas
containing green gelatinous material
also occur {2831}.
Histopathology
Struma ovarii is composed of normal or
hyperplastic thyroid-type tissue with patterns
seen in thyroid adenoma such as
microfollicular, macrofollicular, trabecular
and solid. Oxyphil or clear cells may be
found {2832}. Cystic struma is composed
of thin fibrous septa lined by flat,
cuboidal cells with sparse typical thyroid
follicles in the cyst wall {2831}.
Immunoreactivity for thyroglobulin may
be helpful in problematic cases such as
cystic struma, oxyphilic or clear cell variants
and a trabecular architecture that
might be indistinguishable from Sertoli-
Leydig cell tumours. Criteria used for
malignant changes within struma ovarii
are the same as those used for a diagnosis
of malignancy in the thyroid gland
{677,2387}. Papillary carcinomas (85%
of cases) display the characteristic
ground glass nuclei. However, follicular
Fig. 2.105 Meiotic division. Primordial germ cells are
heterozygous with all informative microsatellite
markers. After the first meiotic division and crossing
over between homologous chromatids, a homozygous
genotype is demonstrated with microsatellite
marker “a” while a heterozygous genotype is seen
with microsatellite marker ”b”.
Prognosis and predictive factors
Tumours with the morphology of papillary
or follicular thyroid cancer and extraovarian
spread at presentation are probably
the only lesions that deserve a designation
of malignant struma, whilst the
so-called "benign strumatosis", peritoneal
implants composed of benign thyroid-type
tissue, does not alter the prognosis.
Factors increasing the likelihood of
recurrences include the size, the presence
of ascites or adhesions and solid
a rc h i t e c t u re, whereas the mitotic rate
and vascular invasion (identified in 15%
of malignant strumas) are not prognostically
helpful features {2387}.
Carcinoids
Definition
These tumours contain extensive components
of well diff e rentiated neuro e n-
docrine cells and most subtypes resemble
carcinoids of the gastro i n t e s t i n a l
tract. They may occur in pure form or
within a dermoid cyst, a mucinous cystic
tumour or a Brenner tumour. It should be
distinguished from isolated neuro e n-
docrine cells found within some mucinous
and Sertoli-Leydig cell tumours.
Epidemiology
Ovarian carcinoids account for 0.5-1.7%
of all carcinoids {2743}, and the age
range is 14-79 years (mean 53) {166,
2388,2390,2392}.
Clinical features
Signs and symptoms
Carcinoid syndrome is a clinical sign of
insular carcinoids in 30% of patients and
is rare in trabecular (13%) and strumal
(3.2%) carcinoids {631,2743}. Peptide
YY production by the tumour cells causes
severe constipation and pain with
defecation in 25% of trabecular carcinoids
{2656}. Strumal carcinoids may
cause symptoms of functioning thyroid
tissue in 8% of cases {2390}.
172 Tumours of the ovary and peritoneum