Clinical history: 55 y/o female with ovarian mass.
What is your diagnosis?
Discussion and answer
Sections taken from the ill-defined nodule show a poorly circumscribed mass with irregular bundles of smooth muscles imparting an overall lobulated configuration. Between the bundles are irregular, anastomosing gland-like spaces lined by mesothelial type cells. Some of the cells have a signet ring type appearance, but no nuclear atypia. The features are those of an adenomyoma, which is a benign, non-invasive lesion.