DOI:10.2214/AJR.04.1895
AJR 2006; 186:483-490
© American Roentgen Ray Society
Solid Extratesticular Masses in Children: Radiographic and Pathologic Correlation
Tammy Sung1,
Wolfram F. J. Riedlinger2,
David A. Diamond3 and
Jeanne S. Chow4
1 Department of Radiology, Brigham and Women's Hospital, 75 Francis St., Boston,
MA 02115.
2 Department of Pathology, Children's Hospital Boston, Boston, MA 02115.
3 Department of Urology, Children's Hospital Boston, Boston, MA 02115.
4 Department of Radiology, Children's Hospital Boston, Boston, MA 02115.
Received December 13, 2004;
accepted after revision January 27, 2005.
Address correspondence to T. Sung
(tsung{at}partners.org).
Abstract
OBJECTIVE. The purpose of this pictorial essay is to review the
sonographic and pathologic appearances of the most common solid and complex
extratesticular masses in children.
CONCLUSION. Solid or complex extratesticular masses, especially
those that are rapidly growing and are painless, raise concerns regarding
malignant rhabdomyosarcoma. Mimickers of rhabdomyosarcoma include inflammatory
processes such as pseudotumor, chronic epididymitis, or meconium periorchitis.
Because sonography cannot distinguish benign from malignant, worrisome
extratesticular masses should be biopsied or removed.
Keywords: genitourinary tract imaging pediatric imaging scrotal disease sonography testicular mass
Introduction
Unlike solid extratesticular masses in adults, which are generally benign
[1], 50% of painless
extratesticular masses in children are malignant
[2]. The most common neoplasm
is paratesticular rhabdomyosarcoma.
Evaluation of scrotal disease in children begins with history and physical
examination. Sonography, the imaging technique of choice
[3], characterizes scrotal
lesions as intratesticular or extratesticular and solid, cystic, or complex
[1]. Cystic extratesticular
masses such as spermatoceles or hydroceles are typically benign and have been
well described [1]. Inguinal
hernias, especially those containing bowel, are diagnosed easily by sonogram.
However, a sonogram cannot determine if a solid and complex extratesticular
mass is benign or malignant
[4].
Using pathologic specimens obtained at Children's Hospital Boston between
1994 and 2004, this pictorial essay reviews the literature and describes
common solid and complex extratesticular masses in children, including
malignant rhabdomyosarcoma. Based on clinical presentation, masses are divided
into two categories: painless and painful.
Painless Masses
Rhabdomyosarcoma
Other than paratesticular lipomas found incidentally during surgery,
rhabdomyosarcomas were the most commonly resected extratesticular masses in
the past 10 years at Children's Hospital Boston. Four percent of these common
childhood tumors occur in the paratesticular location
[5] (Figs.
1A,
1B,
1C,
2A, and
2B). The embryonal subtype is
the most common. Patients typically present with unilateral painless scrotal
swelling not associated with fever. With multimodality therapy, the survival
after rhabdomyosarcoma resection is reported to be 80% at 3 years
[4].

View larger version (117K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1A 4-year-old boy who presented with painless enlargement of right
scrotum due to paratesticular rhabdomyosarcoma. Sagittal sonogram of right
testicle shows heterogeneous solid mass (arrows) encircling testis
(T) separate from epididymis (E). After surgical excision, pathology showed
embryonal-type rhabdomyosarcoma.
|
|

View larger version (185K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1B 4-year-old boy who presented with painless enlargement of right
scrotum due to paratesticular rhabdomyosarcoma. Photomicrograph of
histopathologic specimen shows highly cellular neoplasm composed of abundant
small, round blue cells arranged with lack of cohesive pattern. (H and E,
x10)
|
|

View larger version (157K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1C 4-year-old boy who presented with painless enlargement of right
scrotum due to paratesticular rhabdomyosarcoma. Photomicrograph of
histopathologic specimen shows tumor, composed of undifferentiated small,
round to spindle cells with dark nuclei and scant cytoplasm and interspersed
differentiated rhabdomyoblasts with eosinophilic cytoplasm. Tumor cells are
surrounded by connective tissue with variable myxoid appearance. (H and E,
x60)
|
|

View larger version (138K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2A 15-year-old boy who presented with enlarging painless right scrotal
mass due to rhabdomyosarcoma. Sagittal sonogram shows hypoechoic mass (M)
(arrow) that is separate from adjacent testis (T) and compresses
epididymis (E). There is increased blood flow to mass by color Doppler (not
shown). Surgical excision was performed.
|
|

View larger version (181K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2B 15-year-old boy who presented with enlarging painless right scrotal
mass due to rhabdomyosarcoma. Photomicrograph of histopathologic specimen
shows undifferentiated small, round to spindle cells with dark nuclei and
scant cytoplasm embedded in connective tissue with focal myxoid appearance.
Interspersed are well-differentiated rhabdomyoblasts with eosinophilic
cytoplasm. (H and E, x60)
|
|
Rhabdomyosarcomas vary in appearance from mostly solid to primarily cystic
with solid nodules, reflecting the gross pathologic appearance of a solid mass
with occasional cystic degeneration and hemorrhage.

View larger version (110K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3A 14-year-old boy with painless right scrotal mass secondary to
fibrous pseudotumor. Sagittal sonogram of right scrotum shows hypoechoic mass
(M) (arrow) in epididymis that is discrete and separate from testis
(T).
|
|

View larger version (171K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3B 14-year-old boy with painless right scrotal mass secondary to
fibrous pseudotumor. Photomicrograph of histopathologic specimen shows
granulation tissue composed of capillary-size vessels associated with chronic
inflammatory lymphoplasmacytic cell infiltrate in background of focal
hyalinized fibrous tissue. (H and E, x40)
|
|

View larger version (157K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4A 17-year-old boy who presented with firm, mobile, nonpainful left
scrotal mass secondary to inflammatory pseudotumor. Sagittal sonogram shows
part of normal left testis (T) and large hypoechoic mass (M) (arrow)
that is superior to testis. Mass is homogeneous and well defined and has mild
peripheral vascular flow on color Doppler evaluation (not shown).
|
|
Pseudotumor
Fibrous pseudotumor (chronic periorchitis, nodular fibrous periorchitis,
and nonspecific paratesticular fibrosis) (Figs.
3A and
3B) and inflammatory
pseudotumor (plasma cell granuloma) (Figs.
4A,
4B, and
4C) are benign, reactive,
nonneoplastic lesions of the spermatic cord, epididymis, and tunica caused by
fibroinflammatory reaction. Patients often have a history of trauma or
infection [5].

View larger version (172K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4B 17-year-old boy who presented with firm, mobile, nonpainful left
scrotal mass secondary to inflammatory pseudotumor. Photomicrograph of
histopathologic specimen shows predominantly collagen-filled stroma in a
vaguely nodular pattern with rare interspersed chronic inflammatory cells.
There is neither hemorrhage nor necrosis evident. (H and E, x20)
|
|

View larger version (184K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4C 17-year-old boy who presented with firm, mobile, nonpainful left
scrotal mass secondary to inflammatory pseudotumor. Photomicrograph of
histopathologic specimen shows associated mixed acute and chronic inflammatory
infiltrate encompassing neutrophils, lymphocytes, plasma cells, histiocytes,
eosinophils, and occasional mast cells. Within collagenous background are
spindle cells without nuclear hyperchromasia or cytologic atypia. (H and E,
x20)
|
|
On a sonogram, both variants of pseudotumor mimic rhabdomyosarcoma, and the
diagnosis is rarely made before surgical resection
[1]. However, on histologic
sections, both lesions look distinctly different. Pseudotumors are commonly
associated with hydroceles and hematoceles
[5].
Meconium Periorchitis
Meconium periorchitis (meconium granuloma, meconium vaginalitis) (Figs.
5A and
5B) is a very rare masslike
lesion that arises as a result of inflammatory reaction from meconium within
the scrotal sac. Fewer than 30 cases are described in the literature
[6]. In fetal and early
postnatal periods, a patent processus vaginalis allows spilled meconium from
bowel perforation to spread into the scrotal sac. Consistency and appearance
of meconium in the scrotum evolve over time. Soft extratesticular mass at
birth eventually hardens and becomes partially calcified
[6]. Meconium causes
foreign-body giant-cell reaction, chronic inflammation, and finally, scarring.
Peritoneal and scrotal calcifications resulting from chronic inflammation are
clues to a diagnosis of meconium periorchitis.

View larger version (113K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5A 7-day-old male neonate who presented with severe swelling of scrotum
secondary to meconium periorchitis. Transverse sonogram of scrotum shows
marked skin thickening and complex fluid collections surrounding testis (T).
Multiple echogenic foci with shadowing (arrow) represent calcified
meconium.
|
|

View larger version (174K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 5B 7-day-old male neonate who presented with severe swelling of scrotum
secondary to meconium periorchitis. Photomicrograph of histopathologic
specimen reveals chronically inflamed myxoid stroma with massive accumulation
of polymorphonuclear leukocytes and intermixed chronic inflammatory cells and
with histiocytes harboring browning meconium pigment in their cytoplasm. (H
and E, x40)
|
|

View larger version (95K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 6A 14-year-old boy who presented with hard, mobile, painless scrotal
mass secondary to cellular neurofibroma. Transverse sonogram of bilateral
testes (T) shows a hypoechoic mass (N) that is discrete from adjacent
testicle.
|
|

View larger version (101K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 6B 14-year-old boy who presented with hard, mobile, painless scrotal
mass secondary to cellular neurofibroma. Sagittal sonogram of same patient
shows hypoechoic paratesticular mass (N) (arrow) with increased flow
on color Doppler that is discrete from adjacent testicle (T).
|
|

View larger version (177K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 6C 14-year-old boy who presented with hard, mobile, painless scrotal
mass secondary to cellular neurofibroma. Photomicrograph of histopathologic
specimen shows elongated, irregularly shaped cells without nuclear atypia.
Lesional cells with wavy, dark-staining nuclei are arranged in interlacing
bundles, small whorls, and short fascicles. They are embedded in moderate
amounts of mucoid or collagenous matrix. Mast cells, lymphocytes, and
occasional xanthoma cells are present elsewhere. (H and E, x40)
|
|
Cellular Neurofibroma
Cellular neurofibroma (Figs.
6A,
6B, and
6C) of the spermatic cord is a
rare solid extratesticular mass in adults and children
[7]. Neurofibromas arise from
nerve cells along the muscularis propria or ensheathing small nerves. This
diagnosis should be considered in patients with neurofibromatosis 1 because
this disease is associated with an increased incidence of neurofibromas.
However, when there is no history of neurofibromatosis and the lesion is
solitary, clinical and radiologic findings are nonspecific
[7]. These smooth white-to-tan
tumors rarely have secondary degenerative changes such as cyst formation or
hemorrhage and appear homogeneous on a sonogram.
Painful Scrotal Masses
Epididymal Inflammation
Epididymal inflammation leading to chronic epididymitis can be misdiagnosed
as rhabdomyosarcoma. Although clinical history and the presence of pain help
to differentiate epididymal infection from tumor, the diagnosis is not always
clear [8]. Chronic epididymitis
may feel and appear masslike (Figs.
7A and
7B), mimicking extratesticular
neoplasms.

View larger version (108K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 7A 18-year-old man who presented with palpable right scrotal mass and
vague right testicular pain for 2 months secondary to chronic epididymitis.
Sagittal sonogram of right scrotum shows a solid hypoechoic mass (E) that
appears separate from testis (T) and epididymis with increased flow on color
Doppler imaging. At inguinal exploration, biopsy of mass and pathology showed
chronic epididymitis with fibrosis.
|
|

View larger version (174K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 7B 18-year-old man who presented with palpable right scrotal mass and
vague right testicular pain for 2 months secondary to chronic epididymitis.
Photomicrograph of histopathologic specimen shows variable numbers of chronic
inflammatory cells (i.e., lymphocytes, plasma cells, and histiocytes within
collagenized stroma surrounding unremarkable epididymal tubules and ducts).
Lymphoid follicles with reactive germinal centers and noncaseating epithelioid
granulomas, resulting from sperm-spillage, are seen elsewhere. (H and E,
x20)
|
|

View larger version (115K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 8A 15-year-old boy who presented with 1-week history of right groin and
scrotal pain due to torsed appendix testis. Parasagittal sonogram shows right
testis (T) with adjacent hyperechoic mass (A) without appreciable flow on
color Doppler evaluation.
|
|

View larger version (111K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 8B 15-year-old boy who presented with 1-week history of right groin and
scrotal pain due to torsed appendix testis. Transverse sonogram of same
patient shows heterogeneously echogenic paratesticular mass (A). Although
physical examination and sonogram were consistent with torsed appendix testis,
patient underwent surgical scrotal exploration.
|
|
Torsed Appendix
The appendix epididymis and appendix testis are embryologic remnants of the
mesonephric (wolffian) duct and paramesonephric (müllerian) duct,
respectively [1]. Torsion of
these appendages causes acute scrotal pain and a focal bluish discoloration
beneath the skin (so-called "blue-dot" sign). A tender nodule is
commonly palpated on physical examination
[3]. A sonogram (Figs.
8A,
8B, and
8C) typically shows a
hyperemic hyperechoic small oval mass adjacent to the testis or epididymis,
which may be associated with epididymal inflammation and hydrocele. With time,
the torsed appendages involute and may calcify
[3].

View larger version (171K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 8C 15-year-old boy who presented with 1-week history of right groin and
scrotal pain due to torsed appendix testis. Photomicrograph of histopathologic
specimen shows marked hemorrhagic infarction and ectatic and congested
vascular spaces with leakage and resulting fresh hemorrhage. Scattered
hemosiderin pigment-laden macrophages can be found in areas. (H and E,
x10)
|
|

View larger version (129K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 9A 4-day-old male neonate who presented with swollen penis and swollen,
firm scrotum after circumcision, found to have scrotal abscesses. Sagittal
sonogram shows skin thickening and hyperemia of scrotal skin consistent with
cellulitis. Complex cystic collection is adjacent to testis (T).
|
|

View larger version (115K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 9B 4-day-old male neonate who presented with swollen penis and swollen,
firm scrotum after circumcision, found to have scrotal abscesses. Transverse
sonogram shows marked increased flow surrounding testis (T) and adjacent
complex fluid collection. At surgery, bilateral scrotal abscesses were incised
and drained.
|
|

View larger version (175K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 9C 4-day-old male neonate who presented with swollen penis and swollen,
firm scrotum after circumcision, found to have scrotal abscesses.
Photomicrograph of histopathologic specimen shows sheets of abundant
polymorphonuclear leukocytes and nuclear fragments consistent with abscess. (H
and E, x20)
|
|
Scrotal Abscess
Scrotal abscess (Figs. 9A,
9B, and
9C) can be a complication of
epididymoorchitis, trauma, or surgery. The clinical history and physical
examination of a painful hyperemic scrotum help in making the diagnosis. On a
sonogram, this extratesticular lesion can have a variety of appearances. Areas
of infection are generally hyperemic and heterogeneous in echotexture. If
organized, an abscess may have a well-defined hyperemic wall. If there is gas
within the collection, hyperechoic foci with "dirty" shadowing are
seen.
Conclusion
Solid or complex extratesticular masses, especially those that present as
rapidly growing and painless, may be malignant rhabdomyosarcoma. A history of
trauma or acute pain and findings of erythema or tenderness help to
distinguish acute inflammatory processes from possibly malignant lesions.
Mimickers of rhabdomyosarcoma include chronic inflammatory processes such as
pseudotumor, chronic epididymitis, or meconium periorchitis, and less
commonly, other tumors. Adenomatoid tumors, common in adults, are rare in
children and only one case appeared as an incidental finding in our series. If
there is history of neurofibromatosis 1, the extratesticular mass may
represent a neurofibroma. Lipomas are commonly found in pathologic specimens
but are rarely the cause of the original surgery. Splenogonadal fusion
[5] and supernumerary testes
[1] are also occasionally
diagnosed. Because no pathologically proven cases were reported in our 10-year
search, none was included in this article. Although lymphomas have been
reported in the literature, none was found in our surgical-pathologic
specimens over the past decade.
Because a sonogram cannot distinguish benign from malignant, worrisome
extratesticular masses need to be biopsied or removed.
References
- Woodward PJ, Schwab CM, Sesterhenn IA. From the archives of the
AFIP: extratesticular scrotal massesradiologic-pathologic correlation.
RadioGraphics 2003;23
: 215-240[Abstract/Free Full Text]
- Aragona F, Talenti E, Santacatterina U, Perale R, Passerini Glazel
G. Unusual, benign asymptomatic scrotal masses in children: case reports and
review of the literature. Int Urol Nephrol1994; 26:563
-570[Medline]
- Frush DP, Sheldon CA. Diagnostic imaging for pediatric scrotal
disorders. RadioGraphics 1998;18
: 969-985[Abstract]
- Skoog SJ. Benign and malignant pediatric scrotal masses.
Pediatr Clin North Am 1997;44
: 1229-1250[Medline]
- Akbar SA, Sayyed TA, Jafri SZ, Hasteh F, Neill JS. Multimodality
imaging of paratesticular neoplasms and their rare mimics.
RadioGraphics 2003;23
: 1461-1476[Abstract/Free Full Text]
- Williams HJ, Abernethy LJ, Losty PD, Kotiloglu E. Meconium
periorchitis: a rare cause of a paratesticular mass. Pediatr
Radiol 2004; 34:421
-423[Medline]
- Jiang R, Chen JH, Chen M, Li QM. Male genital schwannoma: review of
5 cases. Asian J Androl 2003;5
: 251-254[Medline]
- Mak CW, Chou CK, Su CC, Huan SK, Chang JM. Ultrasound diagnosis of
paratesticular rhabdomyosarcoma. Br J Radiol2004; 77:250
-252[Abstract/Free Full Text]

CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
J. W. Stengel and E. M. Remer
Sonography of the Scrotum: Self-Assessment Module
Am. J. Roentgenol.,
June 1, 2008;
190(6_Supplement):
S42 - S45.
[Abstract]
[Full Text]
[PDF]
|
 |
|