Discussion:
Mature cystic teratomas, also known as dermoid cysts, are the most
common ovarian neoplasms in women of reproductive age, accounting for
over 95% of all ovarian tumors (1). While often asymptomatic, these
teratomas can cause lower abdominal pain and abdominal fullness as they
progressively enlarge and disturb adjacent structures (2). Complications
associated with dermoid cysts include ovarian torsion, which occurs in
approximately 16% of cases and presents with acute abdominal pain,
nausea, and vomiting (2, 3). Ruptured dermoid cysts can lead to spillage
of sebaceous fluid into the abdominal cavity, resulting in peritonitis,
and rare complications may involve rupture into the intestines, rectum,
or bladder (3). Malignant degeneration can occur in 1-2% of teratoma
cases (2). Large ovarian teratomas can compress abdominal organs and
vasculature, causing complications such as small bowel obstruction,
pelvic vein thrombosis, lower extremity lymphedema, and hydronephrosis
(4, 5).
To aid in the diagnostic workup of mature cystic teratomas, various
imaging modalities play a crucial role. Transvaginal ultrasound (TVUS),
computed tomography (CT), and magnetic resonance imaging (MRI) are
commonly employed. TVUS provides rapid visualization and exhibits a
sensitivity ranging from 58% to 92.7% (2). Notably, ultrasound imaging
reveals the characteristic ”dot-dash” sign, representing echogenic bands
caused by hair within the cystic lumen. The presence of a dense
echogenic tubercle, known as the Rokitansky nodule, is a common feature
observed in 81-86% of dermoid cysts (7). CT and MRI exhibit greater
sensitivity due to their ability to visualize the fat content in
sebaceous material (2, 7, 8). CT imaging, in particular, is commonly
utilized for the diagnosis of mature cystic teratomas and offers a
higher sensitivity (93-98%) compared to ultrasound (7).
Obstructive uropathy caused by mature cystic teratomas is a rare
complication that has received limited attention in the literature. Our
comprehensive literature review identified only a few cases reporting
hydronephrosis resulting from the compressive effect of large mature
cystic teratomas. For example, Adnan et al. reported a case of bilateral
hydronephrosis and pelvic vein thrombosis caused by a giant dermoid cyst
in a 45-year-old woman (4). Two other case reports identified evidence
of hydronephrosis resulting from compression by an ovarian teratoma in
teenage patients (5, 6). To the best of our knowledge, the current case
represents the first documentation of a mature cystic teratoma
complicated by unilateral ureterohydronephrosis, pyelocalyceal rupture,
and subsequent urinoma formation in an adult woman.
In our presented case, a large mature cystic teratoma measuring 7 x 7 cm
caused distal obstruction of the right ureter, leading to the
development of ureterohydronephrosis and urinoma. The considerable size
of the mass resulted in displacement of the uterus and compression of
the right ureter, causing distal obstruction and interruption of urinary
flow. This rare complication, ureterohydronephrosis, was evident on both
ultrasound and CT imaging. Additionally, the identification of a
developing urinoma resulting from pyelocalyceal rupture indicated the
severity of the patient’s clinical presentation, emphasizing the need
for prompt treatment.
Surgical management is the definitive treatment for ovarian teratomas,
and the approach depends on the size of the teratoma. Surveillance is
recommended for teratomas measuring ≤ 5-6 cm, while oophorectomy is
considered the standard treatment for large mature teratomas in both
pre-menopausal and post-menopausal women (9). However, the involvement
of the genitourinary system adds complexity to the management of
patients with mature cystic teratomas, necessitating early diagnosis and
intervention. In situations where a ruptured renal pelvis emerges due to
obstruction, prompt intervention becomes paramount. The primary goal is
to alleviate the obstruction, which in this case was achieved by
surgically excising the teratoma and placing a temporary ureteral stent.
Preventative measures against potential infections, such as
administering antibiotics, coupled with diligent renal function
monitoring, are essential.