Case #02 Discussion:

The definite border, fat-density, and presence of calcifications are all suggestive of a benign cystic teratoma (dermoid cyst). The differential for this mass should include all types of cystic masses (gynecologic and nongynecologic), solid masses, and tumors. The most commonly encountered masses include functional ovarian cysts, endometriosis, serous/mucinous cystadenoma and cystadenocarcinoma, and benign cystic teratoma. Dermoid cysts are common, and, although mainly cystic, ectodermal derivatives such as hair and teeth are frequently present, giving a varied appearance and allowing for diagnosis on plain film radiography. Virtually all dermoid cysts are surgically curable, and fewer than 1% have malignant elements (usually squamous cell carcinoma). Ultrasound is helpful in characterizing the cystic nature of the mass, as well as defining the borders. US guided aspiration/biopsy can also direct further treatment.