Spectrum of mural nodules in mucinous cystic tumours of ovary (MCTO): A rare case of an ovarian mucinous cystadenoma with a mural leiomyoma

Abstract

A 44-year-old female underwent ovarian cystectomy for a multiloculated ovarian cyst. Histologically, the ovarian cyst was found to be a mucinous cystadenoma. A well demarcated 15 mm mural nodule in the tumour was found to be a leiomyoma (confirmed with a Masson’s trichrome stain and immunohistochemical studies for smooth muscle actin, desmin and calponin). A spectrum of mural nodules has been described in association with MCTO that consist of cystadenoma, borderline tumours and cystadenocarcinomas. These nodules have distinctly different macroscopic and microscopic appearances to those of MCTO. Furthermore, they may be benign or overtly malignant and can contain epithelial and/or stromal components. Benign nodules, also called sarcoma-like mural nodules, may contain a mixture of mononucleated spindled cells and multinucleated cells. Malignant forms may resemble anaplastic carcinoma, spindle cell sarcoma or combined carcinoma/sarcoma. Leiomyomas as mural nodules are rarely reported in the literature. Accurate diagnosis of these mural nodules is important, as malignant mural nodules may worsen the prognosis.