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.