Rare recurrence of a multilocular cystic leiomyoma following myomectomy

We here report a rare case of recurrence of a multilocular cystic leiomyoma following myomectomy. Our patient’s clinical course highlights two important points. First, incomplete excision of a multilocular cystic leiomyoma may result in its recurrence as a large cystic mass. Recurrence of a leiomyoma following myomectomy is common. 2 However, to the best of our knowledge, there are no previous reports of recurrent multilocular cystic leiomyomas following myomectomy. The differential diagnosis of a multilocular tumour in the uterine cavity includes degenerative leiomyoma, intrauterine endometrial cyst, and arteriovenous fistula. Cyst formation occurs during the late stages of degeneration as hyaline material liquefies. 3 Endometriosis in the uterine wall has rarely been reported. 4 The presence of an abnormal uterine vascular network with tortuous and serpiginous vessels is suggestive of an arteriovenous fistula. 5 In the present case, the absence of blood flow within the cystic lesion excluded this diagnosis. Because the cystic lesion had indistinct borders, we hypothesised that the previous submucosal leiomyoma had been incompletely excised, leading to regrowth of the original lesion. Second, differentiating between a multilocular cystic leiomyoma and an ovarian tumour may be difficult. The possible differential diagnoses include ovarian tumour, peritoneal inclusion cyst, uterine adenomatoid tumour, and degenerative leiomyoma. One group has reported misdiagnosis of a cystic multilocular leiomyoma as an ovarian tumour. 6 We did not mistake the lesion for an ovarian tumour in the present case because it was localised in the myometrium adjacent to the site of the previous myomectomy and exhibited exophytic growth. Peritoneal inclusion cysts are complex cystic adnexal masses within which a normal ovary can be enclosed by multiple fluid-filled adhesions. Because peritoneal inclusion cysts develop in the presence of peritoneal adhesions and active ovaries, 7 this diagnosis should be considered in women of reproductive age who have undergone pelvic surgery. Adenomatoid tumours of the uterus are occasionally misdiagnosed as other benign or malignant neoplasms. Quigley and Hart proposed the following four distinctive histological types: adenoid, angiomatoid, solid, and cystic. 8 In conclusion, we here present a patient who had a recurrence of a multilocular cystic leiomyoma following myomectomy. It is important to completely resect uterine multilocular cystic lesions to prevent their recurrence.