Invasive breast carcinoma - IARC

Fig. 2.117 Small cell carcinoma, hypercalcaemic
type. The ovary is involved by a solid, knobby tumour
that has extended through the capsule to the right.
This tumour may also be confused with
adult type granulosa cell tumours, malignant
lymphoma and other small cell
malignant neoplasms that involve the
o v a ry {695}. The absence of membrane
i m m u n o reactivity for MIC2 protein (CD99)
serves to distinguish small cell carc i n o m a
f rom primitive neuro e c t o d e rmal tumour
(see section on germ cell tumours).
H i s t o g e n e s i s
The histogenesis of small cell carc i n o m a
has not been definitively established
{755}. It has been proposed that this
tumour may be a variant of a surf a c e
e p i t h e l i a l - s t romal tumour {2376}. A study
utilized a mouse xenograft model in which
tumour fragments of small cell carc i n o m a
w e re cultured in six subsequent generations
of nude mice. The transplanted
tumour morphology remained the same as
that of primary tumour from the patient,
and serum calcium levels were significantly
higher in tumour-bearing mice comp
a red to controls. By comparative genomic
hybridization and electron micro s c o p y
the tumour appeared to be a distinct
tumour entity, not related to either a germ
cell tumour or epithelial ovarian cancer
{3050}.
Genetic susceptibility
The neoplasm has been familial in several
instances. The tumour has occurred in
t h ree sisters, in two cousins and in a
mother and daughter {3204}. The familial
tumours were all bilateral in contrast to the
rarity of bilateral tumours in general.
Small cell carcinoma,
pulmonary type
Definition
A small cell carcinoma resembling pulmonary
small cell carcinomas of neuroendocrine
type.
Synonym
Small cell carcinoma of neuroendocrine
type.
Clinical features
Patients typically are postmenopausal
and present with pelvic or abdominal
masses.
A
Macroscopy
The tumours are typically large and solid
with a cystic component.
Histopathology
The pulmonary type resembles small cell
c a rcinoma of the lung and is associated
with a surface epithelial-stromal tumour,
most often endometrioid carcinoma {761}.
The neoplastic cells have nuclei with finely
stippled chromatin, lack nucleoli and
show molding. The cytoplasm is scant.
Mitoses are numerous. The appearance
varies somewhat depending on cellular
p reservation.
Prognosis and predictive factors
In the largest series of patients appro x i-
mately one-third of patients with stage IA
disease were alive and free of tumour at
last follow up {3204}. Almost all the patients
with a stage higher than IA died of disease.
B
Fig. 2.118 Small cell carcinoma, hypercalcaemic type. A Note the follicle-like space. B There is a diffuse proliferation
of mitotically active small cells with enlarged nuclei that contain small nucleoli.
Miscellaneous tumours and tumour-like conditions of the ovary 183