Presentation
2 day history of severe lower abdominal pain, worse on left side.
Patient Data
Large heterogeneous mass arising from the left ovary, lying anterior to the uterus. The mass contains soft tissue, fat and calcification. Vessels around the edge of the mass pass towards the left side and drain into the left ovarian vein, indicating left ovary as the origin of mass. Right ovary lies right posterolateral to uterus and has a normal appearance. Large volume of free fluid throughout abdomen and pelvis, no fat-fluid levels, and no abscesses. No pneumoperitoneum.
HISTOLOGY REPORT
Clinical History: Ten-day history of abdominal pain worse for the last two days. Ultrasound and CT showed pelvic mass.
Macroscopic: Large intact cyst measuring 115 x 85 x 60mm with a separate tube and cyst wall measuring 75 x 6 x 8mm and separate piece of tissue measuring 35 x 20 x 12mm?ovary. The large cyst contains hemorrhagic fluid and on sectioning a large polypoid mass present measuring 65 x 55 x 40mm. Within a separate area of this cyst there is evidence of hair and sebaceous material.
Microscopic: The ovarian cyst has been widely sampled. In some areas, the cyst is lined by keratinizing stratified squamous epithelium with underlying pilosebaceous units and adipose tissue. Some foetal cartilage is also identified. These features represent a mature teratoma (dermoid cyst). However, multiple blocks from the polypoid tumor mass within the cyst show this is composed of predominantly neural tissue associated with primitive mesenchymal cells and immature neuroepithelium including neuroepithelial tubules and cellular glial tissue. There is some associated squamous and glandular epithelium present together with foetal and immature looking cartilage. Focal spindle/ovoid-shaped cellular proliferation is noted which probably represents immature elements of glial origin associated with mitotic activity. There is no evidence of necrosis. The neural elements were positive for GFAP, S100 andneurofilament. Overall, these appearances represent a high grade (Grade 3) immature teratoma. The normal ovarian tissue contains benign follicular cysts and the Fallopian tube is normal.
Comments: Immature teratoma behaves in a malignant fashion and can metastasize.
Conclusion: Left ovarian cyst - immature teratoma (high grade, Grade 3).
Case Discussion
The imaging findings are those of an ovarian mass containing multiple different tissue types, including fat, soft tissue and calcification, consistent with a teratoma (dermoid cyst). Whether it is mature or immature can only be determined at histopathology analysis. Despite the volume of free fluid on the CT, there was no evidence of cyst rupture on pathology analysis. An important sign here is the path of the blood vessels draining the mass to the left ovarian vein, indicating the left ovary as the origin.