Unicornuate uterus with a functional non-communicating horn in adolescent

Abstract

Common causes of pelvic pain are primary dysmenorrhoea, Müllerian duct anomalies, outflow obstruction, leiomyoma, endometriosis and adenomyosis. Unicornuate uterus with a rudimentary horn is a rare congenital malformation of the female genital tract, asymptomatic because of lack of functional endometrium. This study presents a rare case of a non-communicating functional rudimentary horn. A 16-year-old unmarried Yemeni female adolescent with a history of irregular painful menstrual period visited Obstetrics and Gynaecology outpatient clinic. Pelvic ultrasound was conducted showing an asymmetrical uterine configuration with the non-communicating rudimentary horn on the right side. Laparoscopic excision of the horn was planned for the patient. Non-communicating rudimentary horn with functional endometrium should be considered as a differential diagnosis in the female adolescent with obstructive uterine symptoms. Early diagnosis is crucial. Using the laparoscopic approach, an expert surgeon prefers definitive management to excise the rudimentary horn.

Background

Müllerian duct anomalies (MDAs) are the female genital tract congenital anatomical anomalies, arising either from non-developmental or non-fusion of the Müllerian ducts.^1–3 Unicornuate uterus with a rudimentary horn is a rare congenital malformation of the female genital tract.^{4 5}

Patients with congenital anomalies are asymptomatic due to a lack of functional endometrium. Patients are diagnosed with uterine anomalies using imaging modalities either by an incidental finding done for other purpose or the presented with patient presented with with obstetrical or gynaecological problems such as preterm birth, small for gestation age, malpresentation, ectopic pregnancy in the rudimentary horn or a 50% risk of rupture uterus. Maternal mortality is about <0.5%. The congenital abnormalities include dysmenorrhoea, amenorrhoea, pelvic pain, abdominal mass (haematometra), abnormal bleeding pattern at menarche and infertility.^{1 6–9} In this study, we presented an asymptomatic adolescent case of non-communicating rudimentary uterine horn treated with laparoscopic total excision of the excess horn.

Case presentation

A 16-year-old unmarried Yemeni female adolescent with a history of an irregular painful menstrual period and normal blood flow visited the Obstetrics and Gynaecology outpatient clinic. History of her intermittent pain occurred on attaining her menarche at 11 years of age. However, she has no history of fever, gastrointestinal or urinary symptoms. No significant medical, surgical and family history of the illness. The patient was well nourished. Her general and per-abdominal examination was normal.

Pelvic ultrasound conducted showed an asymmetrical uterine configuration with the non-communicating rudimentary horn on the right side (figure 1). The patient’s distended endometrial cavity was filled with blood (figure 2). Her echogenic endometrium was normal (5.1 mm). The uterine cervix, vagina and both ovaries appear normal in size. No fluid in the pouch of Douglas and appearance of bilateral kidneys are normal (figure 3).

Figure 1.

An asymmetrical uterine configuration with the non-communicating rudimentary horn on the right side.

Figure 2.

Distended endometrial cavity was filled with blood.

Figure 3.

Normal bilateral kidneys.

MRI of the pelvis confirmed the ultrasound findings revealing a non-communicating rudimentary horn cavity distended with haematological contents on the right side (figure 4A–C). The patient was considered for laparoscopic excision of the rudimentary horn.

Figure 4.

(A–C) A non-communicating rudimentary horn cavity distended with haematological contents on the right side.

Preoperatively, a wide diameter of the fundal mass with a dimple was on the top surface and suggested two horns: the right side was more enlarged (figure 5). The right non-communicating horn is attached to the left communicating horn of the uterus (figure 6). Laparoscopic excision of the horn was performed using LigaSure device: an electrosurgical bipolar device for tissue fusion and vessel sealing (figure 7A–C). Her hospital stay was uneventful. No intraoperative or postoperative complications were detected. The patient was discharged on day 3 in stable condition. Histopathological examination of the specimen confirmed the rudimentary horn with adenomyosis. No malignancy is observed. A follow-up examination showed that she had a normal menstrual period with no pain.

Figure 5.

Depression between the two horns.

Figure 6.

Big right uterine horn attached to the left horn.

Figure 7.

(A–C) Excision of the horn using LigaSure.

Investigations

Pelvic ultrasound showed an asymmetrical uterine configuration with a non-communicating rudimentary horn on the right side. The patient’s distended endometrial cavity was filled with blood. Her echogenic endometrium was normal (5.1 mm). The uterine cervix, vagina and both ovaries appear normal in size. No fluid in the pouch of Douglas. The appearance of bilateral kidneys is normal. MRI confirmed the ultrasound findings revealing that the non-communicating rudimentary horn cavity distended with haematological contents on the right side.

Differential diagnosis

Adenomyosis is uncommon in adolescents.

Uterine myoma was not confirmed in the MRI.

The patient has an irregular period. However, imperforated hymen and cervical atresia were not the cases when the patient attained her menarche.

Treatment

The definitive treatement of this condition is an early diagnosis and resection of the rudimentary horn

Outcome and follow-up

Her hospital stay was uneventful. No intraoperative or postoperative complications were detected. The patient was discharged on day 3 in a stable condition. Histopathological examination of the specimen confirmed the rudimentary horn with adenomyosis. No malignancy is observed. A follow-up examination showed that she had a normal menstrual period with no pain.

Discussion

Unicornuate uterus with non-communicating horn is associated with non-developmental or non-fusion of the Müllerian ducts. The estimated incidence is 1:100 000.^1–3 The estimated incidence of MDAs is 1:200 to 1:600 fertile populations,^{4 5} whereas the incidence of the rudimentary horn is very rare at 1:100 000.^{4 5}

According to the American Fertility Society, the unicornuate uterus is Class II classification, subdivided into four subgroups: (1) Class IIa: the rudimentary horn cavity communicates with the uterus, (2) Class IIb: the rudimentary horn cavity does not communicate with the uterus, (3) Class IIc: the rudimentary horn does not have a cavity and (4) Class IId: no horn.

The rudimentary horn can be functional and non-functional. Many are asymptomatic due to a lack of functional endometrium. The congenital abnormalities include dysmenorrhoea, amenorrhoea, pelvic pain, abdominal mass (haematometra), abnormal bleeding pattern at menarche and infertility.^{1 6–9}

Patients with MDAs have a higher risk of developing renal, abdominal wall or skeletal abnormalities.^10–12

Pregnancy in a non-communicating rudimentary horn is extremely rare with an estimation of 1:76 000 to 1:150 000.¹³ Non-communicating rudimentary horn is associated with maternal mortality and complications, such as recurrent pregnancy loss, intrauterine growth restriction and preterm delivery.1 6 7 14

Canis et al. reported the first case in 1990. The preferred standard treatment is the surgical resection of the rudimentary uterine horn. Either laparoscopy or laparotomy is preferred.^15–17

In many other cases, the rudimentary horn was removed laparoscopically.

Patient’s perspective.

My complaint regarding dysmenorrhoea and irregular period kept me under stress to know what’s the cause.

With supportive counselling from my doctor, investigations was done and concluded that I have an excess uterine horn. My complaints resolved after excision of the rudimentary horn approached by laparoscopy.

Learning points.

• The rudimentary horn should be considered as a differential diagnosis of pelvic pain, menstrual outflow obstruction, uterine and vaginal anomalies, endometriosis and uterine myomas in young females.

• The condition is asymptomatic due to a lack of functional endometrium.

• The congenital abnormalities include dysmenorrhoea, amenorrhoea, pelvic pain, abdominal mass (haematometra), abnormal bleeding pattern at menarche and infertility.

• Using the laparoscopy approach, expert surgeons prefer definitive management as an excision of the rudimentary horn.

Ethics statements

Patient consent for publication

Obtained.