Eble JN, Sauter G., Epstein JI, Sesterhenn IA - iarc

Sex cord / gonadal stromal tumours
I.A. Sesterhenn
J. Cheville
P.J. Woodward
I. Damjanov
G.K. Jacobsen
M. Nistal
R. Paniagua
A.A. Renshaw
Sex cord / gonadal stromal
tumours, pure forms
Included in this category are Leydig cell
tumours, Sertoli cell tumours, granulosa
cell tumours and tumours of the thecoma/fibroma
group.
These tumours constitute about 4-6% of
adult testicular tumours and over 30% of
testicular tumours in infants and children.
The name given to this group does not
indicate a preference for any particular
concept of testicular embryogenesis. As
with the germ cell tumours, the aim
throughout this section is to closely parallel
the WHO terminology and classification
of ovarian tumours.
About 10% of these tumours, almost
always in adults, metastasize. However, it
may not be possible on histological
grounds to forecast their behaviour. Some
of these tumours occur in androgen insensitivity
syndrome (AIS) and adrenogenital
syndrome (AGS) and should be classified
under tumour-like lesions.
Leydig cell tumour
Definition
A tumour composed of elements recapitulating
normal development and evolution
of Leydig cells.
ICD-O codes
Leydig cell tumour 8650/1
Malignant Leydig cell tumour 8650/3
Fig. 4.61 Leydig cell tumour.
Synonym
Interstitial cell tumour.
Epidemiology
Leydig cell tumours account for 1-3% of
testicular tumours {1318,1800,2664}. In
infants and children, they constitute about
3% of testis tumours and 14% of stromal
tumours {2366}. Unlike germ cell tumours,
there is no race predilection {1800}.
Occasionally, Leydig cell tumours are
seen in patients with Klinefelter syndrome
{1800,2664}. About 5-10% of patients
have a history of cryptorchidism {1318}.
Clinical features
Signs and symptoms
The tumour is most common in the 3 rd to
6 th decade and in children between 3
and 9 years {1318,2366}. Painless testicular
enlargement is the most common
presentation. Gynecomastia is seen in
about 30% of patients either as a presenting
feature or at clinical evaluation
for a testicular mass {979,2664}. Libido
A
B
Fig. 4.62 Leydig cell tumour. A Typical morphological
appearance. B Leydig cell tumour. Note the
Reinke crystals.
and potency may be compromized. In
children, precocious puberty is not
uncommon {2831}. Leydig cell tumours
produce steroids, particularly testosterone,
androstenedione and dehydroepi-androsterone
{298,2831}. Serum
estrogen and estradiol levels may be elevated
{828}. The latter may be associated
with low testosterone and follicle stimulating
hormone levels {213,1738}.
Progesterone, urinary pregnanediol and
urinary 17-ketosteroid levels may be elevated
{535,2052}. Bilaterality is rare
{1318,1800}.
A
Fig. 4.63 Leydig cell tumour. A Leydig cell tumour with cords of tumour cells. B Tumour cells stain intensely
for inhibin, which is also present to a lesser extend in adjacent tubules.
B
Imaging
Leydig cell tumours are generally well
defined, hypoechoic, small solid masses
but may show cystic areas, haemorrhage
or necrosis. The sonographic
appearance is quite variable and is
indistinguishable from germ cell
tumours. There are no sonographic criteria,
which can differentiate benign from
malignant Leydig cell tumours and
orchiectomy is required.
250 Tumours of the testis and paratesticular tissue