Multinodular Hydropic Leiomyoma in a 41-Year-Old Patient: A Case Report

Uterine leiomyomas are a heterogenous group of benign mesenchymal tumors. While diagnosis is usually achieved through clinical assessment and pelvic ultrasound (PU), atypical subtypes are not as easily recognizable and can be mistaken for malignant tumors such as leiomyosarcoma or ovarian carcinoma. We describe the case of a 41-year-old patient who presented with increasing bulk symptoms, urinary frequency and growth of a hydropic leiomyoma of the left lateral and posterior uterine wall that had been known for 10 years, confirmed with previous biopsy. The tumor filled the entire pelvic cavity in PU and was increasingly difficult to delineate. Considering that the patient had no further desire for future pregnancies, an abdominal hysterectomy without oophorectomy was performed. The patient suffered from an iatrogenic injury to the left ureter and underwent ureteroneocystostomy, from which she recovered fully. Gross tissue examination showed an irregularly enlarged, asymmetric uterus with an intrauterine subserosal mass and an extrauterine papillary tumor arising from the right and posterior uterine wall. The tumor measured 20 x 17 x 10 cm in size. Numerous smooth muscle nodules were observed within the uterus and extending into the extrauterine component in a continuous transition, exhibiting a benign, bland appearance. The nodules were separated by abundant edematous connective tissue with increased vascularization. Histopathological analysis revealed low mitotic activity with no evidence of nuclear atypia, pleomorphism, or necrosis. Immunohistochemical staining confirmed the diagnosis of a benign smooth muscle tumor. The findings suggest a rare, benign smooth muscle neoplasm with both intrauterine and extrauterine involvement.