Full text of DOI:10.1016/S0022-5347(05)67864-0

0022-5347/00/1633-0961/0
®
THE JOURNAL OF UROLOGY
Vol. 163, 961–963, March 2000
Copyright © 2000 by AMERICAN UROLOGICAL ASSOCIATION, INC.®
Printed in U.S.A.
ECTOPIC AND UNDESCENDED TESTES: 2 VARIANTS OF A SINGLE
CONGENITAL ANOMALY?
˜
JOEL C. HUTCHESON, HOWARD M. SNYDER, III, ZACHARY V. ZUNIGA, STEPHEN A. ZDERIC,
DELRAY J. SCHULTZ, DOUGLAS A. CANNING AND DALE S. HUFF
From the Divisions of Pediatric Urology, Children’s Hospital of Philadelphia, Philadelphia and Magee-Woman’s Hospital, Pittsburgh,
Pennsylvania
ABSTRACT
Purpose: We compared pathological findings in ectopic and undescended testis to determine
whether the pathological evidence supports the hypothesis that the 2 conditions are variants of
the same congenital anomaly.
Materials and Methods: We identified 24 boys with ectopic testis not in the superfical inguinal
pouch of Denis Browne. Seven boys were excluded from study due to unavailable clinical records
for 3, contralateral undescended testis in 2 and inadequate biopsy specimens in 2. Pathological
findings of ectopic testis in the remaining 17 patients were compared with those of age matched
patients with unilateral undescended testis. Total germ cell count, testicular volume, patency of
the processus vaginalis and epididymal abnormalities were compared. Data were analyzed using
the Wilcoxon matched pairs signed rank and Fisher’s exact tests.
Results: No difference was noted in total germ cell count (p ϭ 0.33), testicular volume
(p ϭ 0.1475), processus vaginalis patency (p ϭ 0.0854) or epididymal abnormalities (p ϭ 1.00) in
the 2 groups. Of the 24 boys (8%) with ectopic testis 2 also had a contralateral undescended testis.
Conclusions: Similar pathological findings in ectopic and undescended testes as well as the
association of ectopic testis with a contralateral undescended testis suggest that ectopic and
undescended testes are variants of the same congenital anomaly. Thus, boys with ectopic testis
may have an increased incidence of subfertility and testicular malignancy. This spectrum of
abnormal testicular position, and its range of pathological conditions and complications may
appropriately be called the undescended testis sequence.
KEY WORDS: testis; abnormalities; tissue, ectopic; cryptorchidism
Undescended testis or cryptorchidism is a common genito- lum predominates, so that the testis follows it to an abnormal
urinary anomaly in which the testis fails to descend com- position.8
pletely and is located along the normal pathway of descent in
Two recent studies indicated that the testicular histopa-
the retroperitoneum, inguinal canal or scrotal entrance. It is thology of ectopic testis in the superficial inguinal pouch is
noted in 2% to 3% of males at birth. Spontaneous descent similar to that of undescended testes, suggesting that the 2
may occur during year 1 of life and only 0.8% of boys is conditions are variants of the same abnormality.9, 10 If ectopic
affected at age 1 year.1 Some evidence suggests that cryp- testis is caused by mechanical factors without endocrinopa-
torchidism is associated with an incomplete form of hypogo- thy, one may expect that the total germ cell count and tes-
nadotropic hypogonadism.2, 3 The proposed endocrinopathy ticular volume would be greater than in undescended testis.
may result in failed descent, and also in abnormalities of the Furthermore, a lower rate of a patent processus vaginalis
epidiydmis and processus vaginalis.4
and malformed epididymides would be present in patients
The normal surge in gonadotropin and testosterone at 60 to with an ectopic than an undescended testis. At our institu-
90 days of life leads to 2 critical stages in the maturation of tion we noted similar histopathological findings in unde-
male germ cells. Gonocytes disappear and adult dark sper- scended and ectopic testes, specifically a decreased germ cell
matogonia simultaneously appear at ages 3 to 6 months, and count and failed maturation of gonocytes to spermatogonia.
primary spermatocytes appear at ages 4 to 5 years.5, 6 Unde- We compare the pathological findings in ectopic testis at
scended testes often demonstrate abnormal germ cell devel- locations other than the superficial inguinal pouch of Denis
opment, as manifested by a decreased total and an abnormal Browne with those of undescended testis to assess the hy-
differential germ cell count. These abnormalities are associ- pothesis that undescended and ectopic testes are variants of
ated with an increased incidence of subfertility and testicular the same abnormality.
cancer.7
Ectopic testis is thought to result from an abnormality of
terminal testicular descent in which the testis initially de-
MATERIALS AND METHODS
We identified 24 boys with ectopic testis not in the superficial
inguinal pouch of Denis Browne from 2,248 treated with orchio-
pexy and testicular biopsy at Children’s Hospital of Philadel-
phia between 1985 and 1997. Of the patients with an ectopic
scends normally through the external inguinal ring but then
due to some mechanical failure comes to rest at a location
outside the normal pathway of descent. An ectopic testis may
be located in the superficial inguinal pouch of Denis Browne,
perineum and penis, or lateral to the scrotum, pubic region,
thigh or contralateral scrotum. A controversial theory holds
that 1 of 4 proposed nonscrotal branches of the gubernacu-
testis
3 with unavailable medical records, 2 with an
ectopic testis also had an undescended contralateral testis, and
2 with inadequate biopsy specimens were excluded from study,
leaving 17 for analysis. In our case-control study for each of the
17 cases the statistician selected an age matched control with a
Accepted for publication October 15, 1999.
961

962
ECTOPIC AND UNDESCENDED TESTIS
unilateral undescended testis in the inguinal canal and the date scrotum in 3. The processus vaginalis was patent in 4 pa-
of surgery as close as possible to that of the case under study. tients and only 1 had an epididymal abnormality.
Patients who had previously undergone groin surgery or hor-
Age of the 7 boys with an ectopic testis lateral to the
monal therapy, or had an undescended contralateral testis or scrotum ranged from 6.5 to 30 months (mean 16). The ectopic
fewer than 50 tubules in the testicular biopsy were excluded testis was on the right side in 3 patients and on the left side
from each group.
in 4. One boy had a hydrocele on the affected side and 1 had
The position of the ectopic testis was recorded. The ceph- distal hypospadias. The processus vaginalis was patent in 6
alocaudal, ventrodorsal and mediolateral dimensions of the of the 7 cases, while the gubernacular attachment was lateral
testes were measured with calipers, and testicular volume to the scrotum in 6 and scrotal in 1. Three patients had
was calculated using Lambert’s formula.8 The processus epididymal anomalies.
vaginalis was categorized as patent or nonpatent. Epididy-
Age of the 3 boys with a femoral ectopic testis ranged from
mal abnormalities were classified as head-body-tail attached, 10 months to 12 years 8 months (mean 5 years). The ectopic
head detached, tail detached or whole epididymis detached testis was on the right side in 1 patient and on the left side in
from the testis with head and tail attachment being the 2. No associated genitourinary abnormalities were identified
normal configuration. Other features documented but not in any of the 3 cases. The processus vaginalis was patent in
statistically analyzed include patient age, affected side, as- 1 of the 3 boys, while the gubernacular attachment was
sociated genitourinary abnormalities and site of gubernacu- lateral to the scrotum in 1 and femoral in 2. An epididymal
lar attachment.
Biopsy specimens were fixed in 2.5% gluteraldehyde, em-
anomaly was present in 1 case.
No significant difference was noted in ectopic and unde-
bedded in epon, sectioned at 0.4 to 1.0 ␮. and stained with scended testes in the number of germ cells per tubule and
toluidine blue. Using histomorphometric analysis we calcu- testicular volume (p ϭ 0.33 and 0.1475, respectively, see
lated the number of germ cells per seminiferous tubule, in- table). Similarly there was no statistically significant differ-
cluding gonocytes, adult dark and pale spermatogonia, pri- ence in a patent processus vaginalis or epididymal abnormal-
mary spermatocytes and unclassified forms.4 The number of ity. A patent processus vaginalis was present and absent in
germ cells per tubule and volume of the ectopic testes were 11 and 6 patients with ectopic, and in 15 and 2 with unde-
compared with those of the case control undescended testes scended testis, respectively (p ϭ 0.0854). An epididymal ab-
using the Wilcoxon matched pairs signed rank test. The normality was present and absent in 5 and 12 patients with
number of ectopic testes with a patent processus vaginalis ectopic, and in 7 and 10 with undescended testis, respectively
and epididymal abnormalities was compared with those as- (p ϭ 1.00).
sociated with undescended testes using Fisher’s exact test.
DISCUSSION
RESULTS
The mechanism of testicular descent has been a matter of
The 24 boys with ectopic testis at positions other than in debate since 1742, when it was initially described by Hunter.11
the superficial inguinal pouch of Denis Browne comprise More recent evidence suggests that the cause of undescended
1.6% of the 2,248 who underwent orchiopexy and testicular testis may be an incomplete manifestation of hypogonado-
biopsy. Of the 24 ectopic testes 10 were perineal, 10 lateral to tropic hypogonadism.3 Ectopic testis is rare, and the patho-
the scrotum and 4 femoral. Of the 3 testes excluded from genesis has been seldom studied but has traditionally been
study because of unavailable medical records 1 was perineal thought to be due to mechanical factors.
and 2 were lateral to the scrotum, while 1 each of the 2
Two previous studies compared histopathological findings
excluded because of a contralateral undescended testis was of ectopic testes in the superficial inguinal pouch of Denis
perineal and femoral, respectively. Of the 2 cases excluded Browne with those of undescended testes. Snyder et al ob-
due to inadequate biopsy 1 testis was perineal and 1 lateral served no difference in the number of germ cells per seminif-
to the scrotum. Of the 17 cases included in our study 7 testes erous tubule in 75 testes in the superficial inguinal pouch
were perineal, 7 were lateral to the scrotum and 3 were and 491 unilateral undescended testes.9 Herzog et al re-
femoral. These 17 cases are described.
ported that the number of germ cells per seminiferous tubule
Age of the 7 boys with a perineal ectopic testis ranged from in testes in the superficial inguinal pouch was significantly
6 to 30 months (mean 12). Four testes were on the right side lower than that in normal controls and similar to that in low
and 3 were on the left side. The only associated genitourinary undescended testes.10 These 2 studies imply that ectopic
anomaly was a contralateral hydrocele. The gubernacular testes in the superficial inguinal pouch are associated with
attachment was to the perineum in 4 cases and lateral to the the same endocrinopathy proposed as the cause of unde-
Age, germ cells per tubule and testis volume in 17 patients with ectopic testis and controls with undescended testis
Age (mos.)
Germ Cells/Tubule
Vol. (cm.3)
Matched Pair No.
Pt.
Control
Pt.
Control
Pt.
Control
1
2
6
6
6
5.5
9
30
11
14
6
19
10
162
6
20
27
31
14
13
17
2.91
2.04
0.46
1.63
2.06
1.71
0.70
0.36
0.48
0.00
3.29
0.15
0.00
0.05
1.69
0.37
6.49
2.17
1.66
0.19
0.18
2.18
0.03
1.01
0.05
1.18
1.61
1.93
0.35
0.98
0.02
0.22
0.78
0.39
1.05
0.66
0.71
0.92
1.01
0.62
0.64
0.29
0.62
3.02
0.74
0.59
0.45
0.59
0.47
0.71
0.51
1.60
0.85
0.89
0.63
1.01
0.85
0.51
0.35
0.64
7.66
0.49
0.78
0.91
0.39
0.51
0.95
0.51
3
9
4
30
11
14
7.5
20
10
5
6
7
8
9
10
11
12
13
14
15
16
17
150
6.5
20
27
30
14
13
4

ECTOPIC AND UNDESCENDED TESTIS
963
scended testes. Elevated temperature related to abnormal
position may have a role in the pathogenesis of germ cell
abnormalities in cryptorchid and ectopic testes.12, 13 How-
ever, we have observed germ cell abnormalities in the con-
tralateral, normally descended testis in patients with a cryp-
torchid testis.14
Our study shows that ectopic testes not in the superficial
inguinal pouch have a similar decrease in the number of
germ cells per tubule and testicular volume as well as similar
abnormalities of the processus vaginalis and epididymis as
those associated with undescended testes. Furthermore, ap-
proximately 8% of patients with an ectopic testis also have an
undescended contralateral testis.
gonadal axis in cryptorchid infants and children. Eur J Ped,
suppl., 146: S2, 1987
4. Elder, J. S.: Epididymal anomalies associated with hydrocele/
hernia and cryptorchidism: implications regarding testicular
descent. J Urol, 148: 624, 1992
5. Huff, D. S., Wu, H.-Y., Snyder, H. M., III et al: Early postnatal
testicular maldevelopment in cryptorchidism. J Urol, 146: 630,
1991
6. Baker, B. A., Morley, R. and Lucas, A.: Plasma testosterone in
preterm infants with cryptorchidism. Arch Dis Child, 63: 1198,
1988
7. Kogan, J. S.: Fertility in cryptorchidism. In: Cryptorchidism:
Management and Implications. Edited by F. Hadz˘iselimovic´.
New York: Springer-Verlag, chapt. 6, pp. 71–82, 1983
8. Rajfer, J.: Congenital anomalies of the testis and scrotum. In:
Campbell’s Urology, 7th ed. Edited by P. C. Walsh, A. B. Retik,
E. D. Vaughan, Jr. et al. Philadelphia: W. B. Saunders Co., vol.
2, chapt. 72, pp. 2172–2192, 1998
CONCLUSIONS
Our findings imply that undescended and ectopic testes in
the superficial inguinal pouch or at any other location may be
variants of the same congenital anomaly. Ectopic testis may
be due to the same endocrinopathy, and may cause a similar
risk for future subfertility and testicular malignancy. This
spectrum of abnormal testicular positions, and their range of
pathological conditions and complications may appropriately
be called the undescended testis sequence.
9. Snyder, H. M., III, Wu, H.-Y., Huff, D. S. et al: The undescended
testis in the superficial inguinal pouch is not ectopic. J Urol,
145: 278A, abstract 261, 1991
10. Herzog, B., Steigert, M. and Hadz˘iselimovic´, F.: Is a testis lo-
cated at the superficial inguinal pouch (Denis Browne Pouch)
comparable to a true cryptorchid testis? J Urol, 148: 622, 1992
11. Backhouse, K. M.: The natural history of testicular descent and
maldescent. Proc Roy Soc Med, 59: 357, 1966
12. Parvinen, M.: Observations on freshly isolated and accurately
identified spermatogenic cells of the rat. Early effects of heat
and short-time experimental cryptorchidism. Virchows Arch B
Cell Pathol, 13: 38, 1973
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