Ruptured Median Raphe Cyst Mimicking a Vascular Penile Mass on Ultrasound

Abstract

Median raphe cysts are uncommon benign cysts thought to occur due to improper fusion of the genital tubercle and can occur anywhere along the median raphe, from the glans to the anus, most commonly occurring along the ventral penile shaft. Limited information is available in the literature about the common imaging features of median raphe cysts with available reports highlighting an avascular cystic lesion. Our case demonstrates a 10-year-old male patient presenting with a ventral penile mass that demonstrated interval growth in the absence of trauma without overlying skin changes. Doppler ultrasound examination demonstrated a solid vascular mass measuring up to 1.6 cm at the ventral aspect of the penis with arterial and venous waveforms. The patient underwent elective resection of the mass which revealed a 2.0 cm inflamed glandular subtype median raphe cyst. This report demonstrates an atypical imaging presentation of an inflamed median raphe cyst, particularly that of a heterogeneous solid mass with arterial and venous blood flow on ultrasound.

Full text

Case Report
Ruptured Median Raphe Cyst Mimicking a Vascular Penile Mass
on Ultrasound
Amir Pakray ,
1
Andrew Surro,
1
Donald Gibson,
1
and Ahmad Tahawi
2
1
Department of Diagnostic Radiology, Beaumont Hospital, Royal Oak, MI, Michigan, USA
2
Michigan State University College of Osteopathic Medicine, East Lansing, MI, Michigan, USA
Correspondence should be addressed to Amir Pakray; amir.pakray@beaumont.org
Received 19 September 2020; Revised 7 December 2021; Accepted 7 February 2022; Published 28 February 2022
Academic Editor: Daniel P. Link
Copyright © 2022 Amir Pakray et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Median raphe cysts are uncommon benign cysts thought to occur due to improper fusion of the genital tubercle and can occur
anywhere along the median raphe, from the glans to the anus, most commonly occurring along the ventral penile shaft.
Limited information is available in the literature about the common imaging features of median raphe cysts with available
reports highlighting an avascular cystic lesion. Our case demonstrates a 10-year-old male patient presenting with a ventral
penile mass that demonstrated interval growth in the absence of trauma without overlying skin changes. Doppler ultrasound
examination demonstrated a solid vascular mass measuring up to 1.6 cm at the ventral aspect of the penis with arterial and
venous waveforms. The patient underwent elective resection of the mass which revealed a 2.0 cm inflamed glandular subtype
median raphe cyst. This report demonstrates an atypical imaging presentation of an inflamed median raphe cyst, particularly
that of a heterogeneous solid mass with arterial and venous blood flow on ultrasound.
1. Introduction
Median raphe cysts (MRC) are rare benign cysts known to
occur along the median raphe, which extends from the
urethral meatus and continues caudally along the scrotum
down to the perineum. They are thought to arise due to
abnormal fusion of the genital tubercle during the fourth
week of fetal development; however, various theories exist
in the literature with the exact pathogenesis uncertain [1].
Approximately 100 cases of median raphe cysts have been
reported to date. A review of these reports demonstrates
encounters by pediatricians, urologists, pathologists, der-
matologists, and radiologists, elucidating the importance
in understanding the multidisciplinary presentation of
MRCs for proper diagnosis and management. A bimodal
pattern of presentation has been noted (1-10 years age
and 21-40 years age) with the patient typically presenting
with cosmetic concerns. [2]. A majority of these lesions
are asymptomatic, and when symptomatic, issues with
urination and coitus are the most common presenting
concerns [2]. Literature has shown that more distal MRCs
along the median raphe are more commonly associated
with symptoms such as difficulty micturating [2].
MRCs are often misdiagnosed as more common entities
such as Cowper gland cysts, dermoid cysts, steatocystomas,
or neoplasms depending on the location [3]. The diagnosis
of an MRC is typically a clinical one however imaging can
be useful to evaluate composition, vascularity, and the extent
of the lesion. A definitive diagnosis is ultimately made on
histological examination. Various histological subtypes have
been demonstrated, most commonly the urethral type which
is composed of a urothelium-like epithelium, whereas the
glandular subtype occurs less commonly [2, 3]. In fact, as
noted by Syed et al., a compilation of reviews displayed only
3 glandular subtypes among 55 patients, highlighting the
novelty of our case [3]. Ultrasound and MRI allow for ana-
tomical assessment in order to understand the extent of
the lesion and to rule out communication with neighboring
structures or vascularity. Typical imaging features described
in the literature are that of an avascular cyst on ultrasound
[3–6]. Similarly, a cystic structure with high T2 signal can
be seen on MRI imaging [4, 7]. A urethrogram may be
Hindawi
Case Reports in Radiology
Volume 2022, Article ID 8899541, 4 pages
https://doi.org/10.1155/2022/8899541

obtained if suspected fistulous urethral communication is
not definitively ruled out on US or MRI. Standard of care
for MRC treatment involves local excision with primary
closure, however, there are case reports noting success
with various options from simple aspiration to wide local
excision with deroofing for deeper/larger lesions [8].
Delayed intervention can result in inflammation of the
MRC increasing the likelihood of iatrogenic urethral injury
in addition to the cosmetic and symptomatic
manifestations of treatment delay [5].
2. Case Presentation
A 10-year-old male with no significant past medical history
presented to the emergency department with isolated penile
shaft swelling and minimal pain without infectious symp-
toms, difficulty urinating or hematuria. The patient denied
any trauma to the area of concern and was discharged with
instructions to follow up with his primary care physician
(PCP). An assessment by the PCP on the next day showed
the swelling had decreased, and the patient was sent home
with hydroxyzine for pruritus and irritation. At the one week
follow up with the PCP, the patient displayed continued
decrease in edema with a firm palpable mass at the distal
ventral aspect of the penis. The patient also reluctantly con-
firmed that the mass had been present for as long as he could
remember, however, he added that it had recently enlarged.
Penile ultrasound was then performed which exhibited a
heterogeneous solid mass measuring 1:4×1:0×1:6cm aris-
ing from the subcutaneous tissue of the distal ventral shaft
and appeared separate from the left corpus cavernosum
and urethra (Figure 1). Color Doppler revealed vascular flow
within the lesion (Figure 2), and Spectral Doppler showed
arterial and venous waveforms within the lesion (Figure 3).
These imaging features are not typical of median raphe cysts
or other common cystic lesions, and a neoplastic etiology
was favored rather than a benign cystic lesion.
Five days later, the patient was taken to the operating
room where a 2 cm mass was identified. The mass was very
adherent to the spongiosum and right corporal body on
the ventral aspect below the coronal sulcus. The mass
appeared cystic in nature and when entered, thick brown/
yellow material was encountered. Cultures displayed no
growth however many polymorphonuclear leukocytes and
red blood cells were seen. Frozen sections demonstrated a
benign cystic lesion lined with mucin-producing cuboidal
epithelium and urothelium consistent with an inflamed
glandular type median raphe cyst with focal rupture
(Figure 4). Subsequent cystoscopy confirmed no fistulous
tract between the mass and the urethra.
3. Discussion
Our case is a novel presentation of a median raphe cyst
masquerading as a large vascular penile shaft mass. Typical
imaging features of MRCs in the literature are those of an
avascular cystic lesion on ultrasound [3–6]. Our case dem-
onstrates several atypical imaging features on ultrasound
including an internal echogenicity suggestive of a solid mass.
The most atypical feature was internal Doppler flow with
arterial and venous waveforms on spectral analysis, which
is most consistent with a vascular mass. These imaging fea-
tures warranted the diagnostic consideration of a neoplastic
etiology. Although a penile neoplasm and benign cystic
lesion would both be managed operatively, a preliminary
diagnosis of a penile neoplasm may cause unnecessary stress
to the patient and family. Two case reports, Yu et al. and
Parnham et al., describe a solid-appearing lesion on ultra-
sound, however, both studies demonstrated an avascular
mass unlike our case [4, 7]. In the case described by Yu
(a) (b)
Figure 1: Grey scale ultrasound of the penile median raphe cyst. (a) Transverse view of the distal penile shaft demonstrating the
heterogeneous solid mass (arrows) in relation to the corpora cavernosa (∗) and corpus spongiosum (+). (b) Sagittal view demonstrating
the solid-appearing median raphe cyst (∗) at the ventrolateral aspect of the distal penile shaft.
⁎
⁎
+
Figure 2: Grey scale ultrasound with Doppler demonstrating
Doppler flow to the median raphe cyst (arrows). The corpora
cavernosa (∗) and corpus spongiosum (+) are seen distinct from
the cyst.
2 Case Reports in Radiology

and Capolicchio, the lesion demonstrated a high T2 signal
on MRI consistent with a cyst [7]. The median raphe cyst
appearing as a soft tissue lesion by Parnham et al. also did
not demonstrate vascularity or enhancement on contrast-
enhanced imaging [4]. Our case highlights the importance
of considering a complicated median raphe cyst in the differ-
ential of a midline penile lesion which appears solid and
demonstrates internal vascularity.
Given the lack of infectious symptoms or overlying signs
of cellulitis, consideration of an infected MRC was not
immediately entertained. When an MRC is infected, the
patient may present with pain, overlying erythema, or exud-
ing pus typically occurring post coitum [3]. In addition to
considering an infected MRC when the history suggests
interval increase in size, one must consider rupture as well.
In our case, the history of recent enlargement without overt
infectious symptoms or history of intercourse may have sug-
gested rupture rather than infection. The patient had no
operative complications, and satisfactory results on follow-
up were noted. Postoperative fistulous complications have
been reported [2], therefore, caution should be taken in cases
where inflammation or adhesions are encountered in
infected or ruptured MRCs.
Our case also demonstrates the limitations of lesion
characterization on ultrasound. Typical cystic penile lesions
are seen on ultrasound as avascular anechoic structures
and may have internal echoes if complicated by debris such
as protein [9]. Acoustic through transmission is another
common identifying feature of cysts. Additionally, internal
Doppler flow should not be present in cysts whereas it is a
feature seen with vascular masses.
4. Conclusion
We present a novel case of a ruptured glandular subtype
median raphe cyst in a 10-year-old with recent enlargement
prior to presentation. A ruptured MRC should be considered
in the differential when a solid vascular subcutaneous mass
is noted along the median raphe without communication
with adjacent structures and lack of clinical infectious find-
ings. A ruptured MRC may present as a relatively large
lesion (>1.5 cm) with arterial and venous flow as demon-
strated in our case.
Data Availability
Additional data such as full DICOM images are available
from the corresponding author upon request.
Conflicts of Interest
The authors declare that they have no conflicts of interest.
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