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

Lymphoma and plasmacytoma of the
testis and paratesticular tissues
A. Marx
P.J. Woodward
Definition
Primary lymphomas or plasmacytomas
of testes or paratesticular tissues arise in
the testicles, epididymis or spermatic
cord and are neither associated with lymphoma
elsewhere nor leukemia. Involvement
of these anatomic structures by
systemic lymphomas/leukemias or plasma
cell myeloma defines secondary testicular
or paratesticular lymphomas or
plasma cell neoplasias.
Incidence and clinical features
Testicular lymphoma (TL) and
plasmacytoma
The majority of primary lymphomas of the
male genital tract arise in the testes {756,
1429,2944,2945}. Testicular lymphomas
(TL) constitute 2% of all testicular neoplasms,
2% of all high grade lymphomas
and 5% of all extranodal lymphomas in
men. Primary (stage IE) TL constitute 40-
60% of all TL {1429,2944,2945}. Most
patients with TL are 60-80 years of age
(19-91), and in this age group TL is the
single most frequent testicular tumour
{2001,2938,2945}.
Only single cases of primary plasmacytoma
of the testis, all in older men, have been
reported {1166,1968,2541}. One case was
associated with HIV infection {2138}.
In children primary testicular lymphomas
are rare and typically occur prior to
puberty (3–10 years of age) {767,1761,
1999,2076}. Secondary involvement of
A
the testis occurs in about 5% of childhood
systemic lymphomas {547,1296}.
Paratesticular lymphoma and
plasmacytoma
The majority of paratesticular lymphomas
is seen in connection with TL, and 25-
60% of TL show extension to paratesticular
sites {509,756,767,1670,2944}.
Secondary involvement of paratesticular
structures in the absence of testicular
lymphoma is exceedingly rare {1073}.
Primary paratesticular lymphomas {1073,
1288,1670,2718} and plasmacytomas
{758} are rare as well. Primary paratesticular
lymphoma appears to peak in a
young (20–30 years of age) {1073} and
an older (34–73 years of age) {1073,
2718} age group with a favourable clinical
course only in the former {1073}.
Clinical features and macroscopy
Primary lymphoma and plasmacytoma of
testis and paratesticular tissues typically
present with unilateral enlargement of the
scrotum or swelling in the inguinal
region. “B-symptoms” are rare in primary
lesions. Bilateral simultaneous involvement
of the testis is typical for lymphoblastic
lymphoma, but rare in other
entities {756}. Bilateral paratesticular
lymphoma is rare as well {1670}. By contrast,
involvement of the contralateral
testis during lymphoma recurrence is
common (10-40%) {1429,2944,2945}.
Fig. 4.87 Lymphoma. A Coronal T2-weighted MRI shows these lesions as hypointense masses (arrows) within
the normal higher signal parenchyma. B Lymphoma involving the spermatic cord. Axial CT image through
the level of the spermatic cord shows diffuse enlargement on the right side by a soft tissue mass (large
arrow). The left spermatic cord is normal (small arrow).
B
Macroscopically, the cut surface usually
reveals poorly demarcated tan, grey and
necrotic or haemorrhagic single or multiple
nodules or diffuse enlargement of
testis or paratesticular tissues {767,1073,
1296,2076,2718}.
Imaging
Testicular lymphoma
The sonographic appearance of testicular
lymphoma is variable and often indistinguishable
from that of germ cell tumours.
They are generally discrete hypoechoic
lesions, which may completely infiltrate
the testis {913,1657}. In contrast to most
germ cell tumours, lymphoma is often
bilateral and multifocal. It may also
involve the extratesticular tissues.
Paratesticular lymphoma
Paratesticular lymphoma may appear
radiologically as multiple nodules or as
diffuse infiltration of the epididymis or
spermatic cord {2070}. Sonographically
lymphomatous masses will generally be
hypoechoic. The testes are usually also
involved. When multiple masses are
identified involving both the testicular
and extratesticular tissues lymphoma is
the first consideration. Although less
common, metastases can give a similar
appearance.
Histopathology
Testicular lymphoma (TL) and
plasmacytoma
In adult testis, primary diffuse large B-
cell lymphoma (DLCL) is the single most
frequent lymphoma (70-80%) {1429,
2944,2945}. DLCL cells infiltrate around
seminiferous tubules, cause arrest of
spermatogenesis, interstitial fibrosis,
tubular hyalinization and loss of tubules
{756,2825}. Primary MALT lymphomas
{1174}, follicular lymphomas {756}, T-cell
lymphomas {1131,2825}, and CD56+,
EBV-associated T/NK-cell lymphomas of
nasal type {402} are exceptional.
Primary testicular plasmacytoma is less
frequent than DLCL {98,643,756,1486,
2497}. It forms nodules composed of
Lymphoma and plasmacytoma of the testis and paratesticular tissues 263