CHAPTER X CHAPTER 4 - Cancer et environnement

A
B
the surgical scar and adjacent tissue of
the skin, scrotum, epididymis or cord and
metastasis have been found in inguinal
and retroperitoneal nodes, abdominal
peritoneum, lungs, mediastinum, bone
and brain {1239,2051}. There have been
reports of peritoneal mesotheliomas presenting
initially in the tunica vaginalis
{36} and of simultaneous mesotheliomas
of pleura, peritoneum and tunica vaginalis
{124}. We have seen other cases in
which the intrascrotal lesions preceded
peritoneal and/or pleural disease by up
to four years.
C
Fig. 4.96 A Adenomatoid tumour. This is the classic tubular morphology with vacuolated cells. B Vacuolated
cells mimicking endothelial cells. Masson trichrome stain. C In this example the stroma is entirely smooth
muscle. Masson trichrome stain. D Peripheral lymphocytic aggregates are commonly seen.
only 80 cases had been reported {353}.
In one study of all mesotheliomas, including
pleural, peritoneal and pericardial,
only 6 of 1785 were of tunica vaginalis
origin {1836}.
Clinical features
The age at presentation ranges from 6 to
91 years with most occurring between
ages 55 and 75 {2051}. 10% of reported
cases have been in patients younger
than 25 years {2051,2664}. In descending
order of frequency paratesticular
mesotheliomas have been discovered
incidental to hernia repair, a palpable
tumour associated with a hydrocele and
a palpable tumour only. There have also
been sporadic cases presenting with
localized soreness or swelling, acute
hydrocele, recurrent hydrocele, haematocele
and diffuse thickening of the spermatic
cord. It is now possible to anticipate
the correct diagnosis with imaging
studies, particularly when combined with
cytology {2051}. Demonstration of multiple
nodular masses within a hydrocele,
particularly if irregular contours are
seen, will generally prove to be a
mesothelioma {819}. The incidence of
asbestos exposure in patients with tunica
vaginalis mesotheliomas has been
cited as 23% {2051}, 41% {1239} and
even 50% in a small series {135}. To
date, asbestos exposure is the only
D
known risk factor and the incidence of
exposure correlates with that reported
for pleural tumours {1239}.
Macroscopy
The common appearance of the gross
specimen is thickening of the tunica
vaginalis with multiple friable nodules or
excrescences. The tunica albuginea may
also be involved. The fluid of the hydrocele
sac is described as clear or
haemorrhagic {1239,1800,2051}. White
or tan masses of firm tissue may be
found where the tumour infiltrates into the
hilus or periphery of the testis or into the
epididymis or spermatic cord.
Tumour spread
Most recurrences occur in the first 2
years of follow-up {2090} and are seen in
Fig. 4.97 Malignant mesothelioma. Tunica vaginalis
with multiple friable excrescences.
Histopathology
Microscopically about 75% of these will
be purely epithelial in type while the others
are biphasic, with varying amounts of
the sarcomatoid morphology {287,1239,
2051}. The epithelial type usually shows
a papillary and tubulopapillary morphology,
often with solid sheets of cells. The
cell structure is variable; the cells covering
the papillations are usually rounded
or cuboidal, often with a bland appearance
but may be flattened or low columnar.
Where the cells are arranged in solid
sheets, variation in size and shape is the
rule. The cytoplasm is eosinophilic and
varies in amount {1800}. Nucleoli are
often prominent. The sarcomatoid element
shows fascicles of spindle cells
which may include a storiform pattern
similar to malignant fibrous histiocytoma
{1239}. Mesotheliomas of the tunica will
usually show cellular atypia of the
mesothelial surface indicative of in situ
neoplasia {2051}.
Immunohistochemistry
By immunohistochemistry the cells are
uniformly reactive with cytokeratin
(AE1/AE3) in both epithelial and spindle
cell elements. EMA and vimentin are also
usually positive and calretinin has been
Fig. 4.98 Malignant mesothelioma with tubulopapillary
morphology.
268 Tumours of the testis and paratesticular tissue