Mitotically Active Leiomyoma in a Woman with Mayer-Rokitansky-Küster-Hauser Syndrome: A Case Report.

Cases of women with Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome developing leiomyomata are rare. A case with mitotically active leiomyomata has not previously been described to our knowledge.A 43-year-old woman with MRKH syndrome found to have an incidental pelvic mass on imaging studies underwent a diagnostic laparoscopy, followed by resection of leiomyomata and uterine remnant via mini laparotomy. Histopathology revealed focal infarction associated with a mitotically active area in one of the leiomyomata but with no evidence of marked cytologic atypia or hypercellularity. Focal adenomyosis was also noted.Studies have shown that mitotically active smooth cell tumors of the uterus having 5-9 mitoses/10 hpf and no cellular atypia have a metastatic rate too low to be regarded as sarcomas. Although the pathology findings in this case are benign with no need for continued surveillance by gynecologic oncology, regular follow-up with a gynecologist annually may be indicated for early diagnosis of recurrence secondary to the uncommon characteristics of this benign tumor, especially in this rare category of patients with Müllerian agenesis. Mitotically active leiomyomata can occur in patients with Müllerian agenesis, but the likelihood that a pelvic mass in a patient with MRKH syndrome is a sarcoma is extremely low.