New Cases of Accessory and Cavitated Uterine Masses (ACUM)

A Significant Cause of Severe Dysmenorrhea and Recurrent Pelvic Pain in Young Women

P. Acién; A. Bataller; F. Fernández; M.I. Acién; J.M. Rodríguez; M.J. Mayol


Hum Reprod. 2012;27(3):683-694. 

In This Article

Abstract and Introduction


BACKGROUND To raise awareness about the accessory and cavitated uterine masses (ACUM) with functional endometrium as a different entity from adult adenomyosis and to highlight the importance of a correct diagnosis, we studied four new cases of ACUM and 15 cases reported as juvenile cystic adenomyoma (JCA) by reviewing the literature from the last year. This entity is problematic because of a broad differential diagnosis, including rudimentary and cavitated uterine horns; and is generally underdiagnosed, being more frequent than previously thought.
METHODS We report four cases of young women who underwent surgery in our hospital from January to July 2011 after presenting with an ACUM. We also reviewed and tabulated the cases from literature beginning in 2010. Main outcome measures were diagnostic tools, surgical and histopathological findings and improvement of symptoms.
RESULTS The addition of the four cases reported here to the 15 published as JCA raises the total number of cases of ACUMs to 19, which is more than all of the cases reported prior to 2010. In our cases, it is interesting to highlight that one of them also had an adjacent accessory rudimentary tube and another had two ACUMs at the same location. All patients suffered from severe dysmenorrhea and pelvic pain and were young women. Suspicion, transvaginal ultrasound and magnetic resonance image were found to be the best diagnostic tools. Most of the cases were treated by laparoscopic tumorectomy.
CONCLUSIONS ACUMs are generally underdiagnosed and often reported as JCAs but they are not adenomyosis. Early surgical treatment involving the laparoscopic or laparotomic removal of the mass could prevent the usual prolonged suffering of these young women. In our opinion, this entity is a new variety of Müllerian anomaly.


In a recent publication (Acién et al., 2010), we suggested that most of the published cases of non-communicating accessory uterine cavities and juvenile or isolated cystic adenomyomas, as well as some cases of uterus-like masses, were actually the same pathology: an accessory and cavitated uterine masses (ACUM) with a functional endometrium. In that article, we reviewed the literature and found 18 cases (including 4 cases reported by us) that we considered to be ACUMs but had been described as accessory uterine cavities, isolated or juvenile cystic adenomyomas (JCAs), or as uterus-like masses. We found another 11 cases that were questionable. It has been suggested that ACUMs represent a new variety of Müllerian anomaly that is generally located at the level of the insertion of the round ligament and is possibly related to a dysfunction of the female gubernaculum (Acién et al., 2011). However, ACUMs have been generally observed in women with an otherwise normal uterus and they are single, but we will see that probably this is not always so.

An ACUM is a rare pathology, observed in young women, that has significant clinical manifestations, particularly severe dysmenorrhea and recurrent pelvic pain. ACUMs are problematic because of the broad differential diagnosis, which includes rudimentary and cavitated uterine horns such as those found in other uterine malformations (bicornuate uterus and segmentary atresias), adenomyosis with cystic or degenerated areas, degenerated leiomyomas, and essential and primary dysmenorrhea. The criteria used to diagnose a case as an ACUM are the following: (i) an isolated accessory cavitated mass; (ii) a normal uterus (endometrial lumen), Fallopian tubes, and ovaries; (iii) a surgical case with an excised mass and a pathological examination; (iv) an accessory cavity lined by endometrial epithelium with glands and stroma; (v) a chocolate-brown-colored fluid content; and (vi) no adenomyosis (if the uterus has been removed), although there could be small foci of adenomyosis in the myometrium adjacent to the accessory cavity (Acién et al., 2010). Although ACUM is diagnosed more frequently in women <30 years of age and nulliparous women, we present some cases in women older than 30 years and multiparous women. We believe most JCAs are in fact ACUMs because they present similar clinical and histopathological characteristics (Acién et al., 2010).

The objectives of this report are as follows: (i) to raise awareness about this pathology and about the appropriate term, ACUM, as a different entity from adult adenomyosis; (ii) to review the literature beginning in 2010 and to present four new clinical cases attended by us within the first 7 months of 2011; (iii) to review the methods and criteria for the diagnosis of ACUM; and (iv) to provide information about this interesting pathology that is not as infrequent as previously believed, emphasizing the importance of gathering clinical evidence for making a correct diagnosis and the importance of determining the characteristics and localization of the ACUM for quickly choosing the best surgical treatment.


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