Objective

To demonstrate the laparoscopic excision of an accessory cavitated uterine mass (ACUM) and show that atypical anomalies can lead to the misdiagnosis of a noncommunicating rudimentary horn.

Design

Description and step-by-step demonstration of the surgical procedure using a video recording (Canadian Task Force Classification 3).

Setting

University hospital.

Patient(s)

A 17-year-old virgin girl with chronic pelvic pain and severe progressive dysmenorrhea despite using nonsteroidal anti-inflammatory drugs and oral contraceptives since her menarche. We could not perform transvaginal examination and ultrasonography because of the virginity of the girl. Transabdominal ultrasound revealed a 24 × 24-mm heterogeneous cystic mass on the left adnexal region suggesting a noncommunicating functional rudimentary horn. This mass was within the left lateral uterine myometrial wall, and otherwise, the uterus and endometrial cavity seemed normal on ultrasonographic examination. Magnetic resonance imaging showed a cavitated nodule of 25 mm with hemorrhagic components inside the mass on the left side of the uterus and the normal endometrial cavity with a normal size uterus. After detailed evaluation and counseling, a decision was taken to perform laparoscopy.

Intervention(s)

Laparoscopic resection of the ACUM.

Main Outcome Measure(s)

On laparoscopic exploration, we first observed a globular enlargement on the left wall of the uterus under the round ligament. Both the ovaries and the uterus were normal, and there were two normally developed fallopian tubes with no abnormality communicating with the normal uterus. The mass had irregular muscle fibers and ambiguous limits for detaching from the normal myometrial tissue. Afterward, the mass was resected completely without entering the endometrial cavity. It was thought that these irregular borders may be a factor of confusion as a degenerated myoma on the diagnosis. The blunt and sharp dissection methods were used bidirectionally, and finally, the lesion was enucleated. The mass was incised, and chocolate-like brownish fluid spilled out from the cavity of the mass. The endometrium-like epithelium and surrounding muscular layer were seen on the mass. The myometrial defect was approximated and closed with a polyglactin absorbable suture. Histopathological examination revealed the endometrial lining cavitated mass surrounded by myometrium, and thus, it was consistent with the diagnosis of ACUM.

Result(s)

The postoperative period of the patient was uneventful. She was discharged without any complaint. Her severe pelvic pain and symptoms of dysmenorrhea were resolved 1 month after the surgery. We did not prescribe any medication for menstrual suppression and pain management before or after surgery. During the follow-up period, she had a regular menstrual cycle and no pelvic pain and dysmenorrhea for 2 years.

Conclusion(s)

Accessory cavitated uterine mass is a new entity having a normal endometrial cavity and is different from other müllerian duct anomalies. Severe dysmenorrhea and chronic pelvic pain are early-onset, and they are persistent despite using medications, but suspecting this problem is the main determinant for confirming the diagnosis. The final diagnosis of ACUM can be made after resecting the mass and confirming with histopathological examination. Accessory cavitated uterine mass may be confused with a similar lesion of juvenile cystic adenomyosis (JCA). They present very similar clinical and pathological findings, but JCA is a rare form of focal adenomyosis that contains cystic contents inside the lesion, and it has more intense adenomyosis surrounding the endometrial lining of a cavitated mass. In our case, histopathological examination revealed muscle fibers around the endometrial epithelium, with no adenomyotic foci. It was so difficult to distinguish these two similar lesions during the surgery. Thus, we could distinguish ACUM from JCA with this pathological confirmation. Accessory cavitated uterine mass may also be misdiagnosed as U4a of ESHRE/ESGE classification and 2b of ASRM classification, but it should be distinguished from these anomalies. Moreover, it is important to define ACUM clearly in the U4 or U6 class of the ESHRE/ESGE and 2b of ASRM classification systems.

中文翻译：

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一个罕见的苗勒管异常新实体，模仿与半子宫不相通的原始腔：副空洞子宫肿块

客观的

演示腹腔镜切除辅助空洞子宫肿块 (ACUM) 并表明非典型异常可导致误诊为不相通的残角。

设计

使用录像（加拿大工作组分类 3）描述和逐步演示手术过程。

环境

大学医院。

耐心）

一名 17 岁处女女孩，尽管自初潮以来使用了非甾体抗炎药和口服避孕药，但仍患有慢性盆腔疼痛和严重的进行性痛经。由于女孩是处女，我们无法进行经阴道检查和超声检查。经腹超声显示左侧附件区有一个 24 × 24 毫米的不均匀囊性肿块，提示有一个不连通的功能性残角。该肿块位于左侧子宫肌层壁内，除此之外，超声检查子宫和子宫内膜腔似乎正常。磁共振成像显示一个 25 mm 的空洞结节，在子宫左侧的肿块内和正常子宫内膜腔内有出血成分，子宫大小正常。经过详细的评估和咨询，

干预措施

腹腔镜切除 ACUM。

主要观察指标）

在腹腔镜探查中，我们首先观察到圆韧带下子宫左壁呈球状增大。卵巢和子宫均正常，有两条输卵管发育正常，与正常子宫相通无异常。该肿块具有不规则的肌纤维和与正常肌层组织分离的模糊界限。之后，肿块被完全切除，没有进入子宫内膜腔。人们认为，这些不规则的边界可能是作为退化性肌瘤诊断时混淆的一个因素。双向使用钝器和锐器解剖方法，最后将病变摘除。肿块被切开，巧克力样的褐色液体从肿块的空腔中溢出。肿块上可见子宫内膜样上皮及周围肌层。用聚乳酸可吸收缝线对子宫肌层缺损进行近似和闭合。组织病理学检查显示子宫内膜内膜空洞肿块被子宫肌层包围，符合 ACUM 的诊断。

结果）

患者术后期间平安无事。她出院了，没有任何抱怨。她的严重骨盆疼痛和痛经症状在手术后 1 个月得到缓解。我们没有在手术前后开任何抑制月经和疼痛管理的药物。随访期间月经规律，2年无盆腔痛、痛经。

结论

辅助空洞子宫肿块是一种具有正常子宫内膜腔的新实体，与其他苗勒管异常不同。重度痛经和慢性盆腔痛为早发性，尽管使用药物仍持续存在，但怀疑此问题是确诊的主要决定因素。ACUM的最终诊断可在切除肿块并经组织病理学检查确诊后作出。辅助性空洞子宫肿块可能与类似的幼年囊性子宫腺肌病 (JCA) 病变相混淆。它们的临床和病理结果非常相似，但 JCA 是一种罕见的局灶性子宫腺肌病，病灶内含有囊性内容物，并且在空洞肿块的子宫内膜内层周围有更严重的子宫腺肌病。在我们的案例中，组织病理学检查显示子宫内膜上皮周围有肌纤维，无子宫腺肌病灶。在手术过程中很难区分这两个相似的病变。因此，我们可以通过这种病理确认来区分 ACUM 和 JCA。辅助性空洞子宫肿块也可能被误诊为 ESHRE/ESGE 分类的 U4a 和 ASRM 分类的 2b，但应与这些异常区分开来。此外，重要的是在 ESHRE/ESGE 的 U4 或 U6 类和 ASRM 分类系统的 2b 中明确定义 ACUM。辅助性空洞子宫肿块也可能被误诊为 ESHRE/ESGE 分类的 U4a 和 ASRM 分类的 2b，但应与这些异常区分开来。此外，重要的是在 ESHRE/ESGE 的 U4 或 U6 类和 ASRM 分类系统的 2b 中明确定义 ACUM。辅助性空洞子宫肿块也可能被误诊为 ESHRE/ESGE 分类的 U4a 和 ASRM 分类的 2b，但应与这些异常区分开来。此外，重要的是在 ESHRE/ESGE 的 U4 或 U6 类和 ASRM 分类系统的 2b 中明确定义 ACUM。