A case of large uterine cystic adenomyosis outside the uterus after laparoscopic myomectomy: a case report and literature review

The patient, a 36-year-old Chinese woman (gravida 1, para 1) presented to our hospital with complaints of menorrhagia and intermittent right lower abdominal pain persisting for one year. Six years ago, the patient underwent laparoscopic surgery at our hospital for the excision of a 4 cm diameter uterine fibroid (Type 6, the International Federation of Gynecology and Obstetrics leiomyoma subclassification system 2018) with cystic degeneration (Fig.  1 A) located in the right posterior uterine wall near the isthmus of the cervix. During the operation, the location of the uterine fibroid was low and close to the uterine cavity, but the cavity was not opened. Fig. 1 Imaging findings during the patient’s hospitalization. A Pelvic CT scan during the first hospitalization revealed a 4 cm diameter uterine fibroid with cystic degeneration located in the right posterior uterine wall near the isthmus of the cervix B , C Follow-up pelvic CT scan during the second hospitalization revealed a multilocular cystic mass situated on the right posterior side of the uterus that appeared to communicate with the uterine cavity D The second admission CT scan revealed that the cyst was located in the same anatomical site as the uterine fibroid identified on the initial admission CT scan (The uterine artery was used as a reference) E During the second hospitalization, pelvic ultrasound identified a solid-cystic mass measuring 7.5 × 5.5 × 4.7 cm in size within the right adnexal area Imaging findings during the patient’s hospitalization. A Pelvic CT scan during the first hospitalization revealed a 4 cm diameter uterine fibroid with cystic degeneration located in the right posterior uterine wall near the isthmus of the cervix B , C Follow-up pelvic CT scan during the second hospitalization revealed a multilocular cystic mass situated on the right posterior side of the uterus that appeared to communicate with the uterine cavity D The second admission CT scan revealed that the cyst was located in the same anatomical site as the uterine fibroid identified on the initial admission CT scan (The uterine artery was used as a reference) E During the second hospitalization, pelvic ultrasound identified a solid-cystic mass measuring 7.5 × 5.5 × 4.7 cm in size within the right adnexal area Upon admission, pelvic ultrasound revealed a solid-cystic mass measuring 7.5 × 5.5 × 4.7 cm in size within the right adnexal area (Fig.  1 E), while both ovaries appeared normal. Ultrasound also suggested a normal endometrium and uterine cavity. Pelvic computed tomography (CT) revealed a multilocular cystic mass situated on the posterior aspect of the uterus (Fig.  1 B). The density within some cysts was slightly greater and unevenly distributed, with no enhancement observed following contrast agent administration. Notably, there seemed to be communication between this mass and the uterine cavity (Fig.  1 C). No abnormalities were detected in the left adnexal region during CT imaging. The radiological findings suggested that this mass could represent an endometriotic cyst; however, all tumor marker levels were within normal limits. Given the uncertainty regarding its origin prior to surgery but assuming that it was more likely benign in nature, laparoscopic exploration was performed under general anesthesia. During the surgical procedure, we were initially perplexed by the presence of a well-defined cyst measuring approximately 7.5 × 6 cm in the right posterior wall of the uterus (Fig.  2 A), while the bilateral adnexa appeared normal. A local adhesion band was observed behind the uterus, especially in the Douglas cavity, but the cyst was not surrounded by adhesions. Upon removal of the cyst, its root was found to be deeply embedded within the myometrium (Fig.  2 B) and the cyst contained a characteristic chocolate-like fluid (Fig.  2 C). It was evident that this cyst represented uterine cystic adenomyosis communicating with the uterine cavity (Fig.  2 D), which was subsequently confirmed by postoperative pathology examination. The complete excision of the root of the cyst exposed normal myometrial tissue; subsequently, double-layer suturing of both the uterine muscle layer and serous muscle layer was performed using absorbable suture material for optimal healing of the uterine incision (Fig.  2 E and F). Finally, the retrieval bag technique was employed to remove the cyst from the abdominal cavity. Postoperative pathology revealed ectopic endometrial-like tissue in the cyst, and immunohistochemistry revealed CD10 positivity. Both operations were performed by the same surgeon. Reviewing the patient’s CT image after surgery, the CT scan from the second admission revealed that the cyst was located at the same anatomical site as the uterine fibroid identified on the CT scan at the initial admission (Fig.  1 D); the uterine artery was used as a reference. Fig. 2 Laparoscopic findings observed during the patient’s second hospitalization. A Laparoscopic exploration revealed a well-defined, large cyst located in the posterior wall of the uterus on the right side, while both adnexa were normal B , C The root of the cyst was deeply embedded in the myometrium, and its contents consisted of a typical chocolate-like fluid D There was communication between the cyst and the uterine cavity E , F 1 − 0 absorption line was utilized for suturing the uterine muscle layer and plasma muscle layers Laparoscopic findings observed during the patient’s second hospitalization. A Laparoscopic exploration revealed a well-defined, large cyst located in the posterior wall of the uterus on the right side, while both adnexa were normal B , C The root of the cyst was deeply embedded in the myometrium, and its contents consisted of a typical chocolate-like fluid D There was communication between the cyst and the uterine cavity E , F 1 − 0 absorption line was utilized for suturing the uterine muscle layer and plasma muscle layers

Uterine cystic adenomyosis is an infrequent subtype of focal adenomyosis that predominantly affects younger women [ 1 ]. It manifests as one or more fluid-filled cavities within the myometrium containing old bloody fluid and lined with epithelium, endometrial-like glands, and stromal components [ 2 ]. The shedding of endometrial-like tissue from these cavities during the menstrual cycle leads to hemorrhagic infarction in adjacent smooth muscle tissues and the accumulation of blood within the cysts. Enlarged cysts can cause severe dysmenorrhea, chronic pelvic pain, excessive menstrual bleeding, and infertility [ 1 , 3 ]. Based on patient age, this condition is classified into juvenile cystic adenomyosis (JCA) and adult cystic adenomyosis; however, reports on the latter are relatively rare [ 3 ]. In this report, we describe a case of large adult uterine cystic adenomyosis located at the original incision site following laparoscopic myomectomy.

Adenomyosis is a chronic disease, and many patients suffer from dysmenorrhea and chronic pelvic pain during adolescence or at a young age [ 4 ]. Dysmenorrhea, a risk factor for endometriosis according to some authors, plays an important role in increasing the detection rate of endometriosis and adenomyosis [ 5 ]. They reported that the percentage of patients with signs of endometriosis on ultrasound increased to 21% in the presence of this symptom. At the same time, other authors observed that the prevalence of endometriosis in young women with dysmenorrhea and chronic pelvic pain ranged between 25% and 73% [ 6 , 7 ]. However, this painful symptom is often considered a normal and transient symptom in young women. Several other authors [ 8 ] also reported that the ultrasound-based detection rate of pelvic endometriosis was one-third in young patients with severe dysmenorrhea. Adenomyosis and endometriosis are known to have significant detrimental effects on the health and reproductive capabilities of affected individuals. Recent research [ 8 ] suggests that young patients with dysmenorrhea should be referred to an expert sonographer to minimize the delay between the onset of symptoms and diagnosis. It is also important to note the coexistence of adenomyosis and deep infiltrating endometriosis (DIE) in patients with painful pelvic symptoms. Several previous studies [ 5 , 8 , 9 ] reported the coexistence of adenomyosis and DIE in approximately 45–50% of patients. Investigating the presence of adenomyosis in adolescent DIE patients [ 10 ] is of utmost importance for achieving appropriate management. Uterine cystic adenomyosis, a rare subtype of uterine adenomyosis, often remains undiagnosed until surgery. In this case, the diagnosis was clearly established intraoperatively. The typical clinical manifestations include severe dysmenorrhea, pelvic pain, and irregular menstruation. Uterine cystic adenomyosis should be considered when imaging examinations reveal a well-defined cystic lesion filled with hemorrhagic fluid within the myometrium [ 11 ]. However, it is important to note that the reported cystic mass was distinctly located outside the contour of the uterus. Consequently, these cystic masses can be easily misdiagnosed as adnexal-derived tumors. Nonetheless, certain preoperative details can still provide clues suggesting this disease as a possibility; for example, preoperative ultrasound examination indicated normal fallopian tubes and ovaries while CT scans suggested a close association between the cyst and the uterine wall. Given the young age of most patients afflicted with this disease, minimally invasive surgery is considered the preferred approach. Postsurgery, there is a significant improvement in associated dysmenorrhea and a notable increase in the likelihood of successful pregnancy [ 12 ]. Undoubtedly, complete removal of the lesion is highly important. In this case, the root of the cyst was deeply embedded within the myometrium, necessitating meticulous attention to ensure its thorough extraction and exposure of the normal uterine myometrium. Moreover, our proficient suturing technique was employed to facilitate uterine repair. Subsequently, we administered a gonadotropin-releasing hormone (GnRH) analog to the patient for six cycles without any observed recurrence. Goserelin was used to downregulate the function of the pituitary gland to cause low estrogen levels and to inhibit the activity of the ectopic endometrium. Six cycles were administered to achieve the optimal therapeutic effect and reduce recurrence. Currently, the etiology of uterine cystic adenomyosis remains unknown. JCA is believed to be a congenital malformation resulting from developmental defects in the Müllerian duct [ 13 , 14 ], while most researchers accept the endometrial injury invagination theory as the pathogenesis for adult-onset cases [ 15 , 16 ]. Miscarriage, curettage, and surgery are known to increase the risk of both endometrial and myometrial injuries, which can lead to significant uterine adenomyosis and occasionally uterine cystic adenomyosis [ 17 ]. Given the unique location of previous uterine fibroids in our patient’s case, their removal along with subsequent suturing posed considerable challenges that may have caused some damage at the junction between the endometrium and myometrium. This history combined with subsequent endometrial invagination could explain the development of uterine cystic adenomyosis observed in this particular patient. In addition, although there are no reports related to power morcellation and the formation of uterine cystic adenomyosis, power morcellation of uterine masses is a widely reported common pathogenetic mechanism for extrauterine adenomyoma [ 18 ], and morcellation should be performed only within tissue-containing bags.

Clinically, the resection of uterine fibroids at specific sites and subsequent suturing of the uterus pose significant challenges for clinicians, as any defect may result in subsequent adverse events such as uterine cystic adenomyosis, as described in this study. Herein, we present a rare case of large adult uterine cystic adenomyosis located outside the uterus occurring after laparoscopic myomectomy, which further supports the invagination theory of endometrial injury as a potential etiology for adult uterine cystic adenomyosis.