# Obstetrics and Gynecology/Ovarian Neoplasia
## Epidemiology

* With respect to general ovarian neoplasms, 30% of postemenopausal women with adenexal masses have malignant disease, compared to 7% in pre-menopausal women.

### Benign Neoplasia

* The vast majority of young women who present with adenexal masses have functional ovarian cysts.
* Dermoid cysts and serous cystadenomas are tied with respect to the incidence of tumor etiology in reproductive age women.

### Ovarian Cancer

* The median age of diagnosis for ovarian cancer in Canada is 56 years of age.
* 50% of ovarian masses in women over 50 years of age are malignant.
* 75% of women are diagnosed at stage III cancer because of delayed presentation of ovarian cancer symptoms.
* 1/70 women will develop ovarian cancer in their lifetimes.
* Ovarian cancer is the leading cause of gynecological death in North America.
* Ovarian cancer is the 5th most common malignancy in North America
* 90% of all ovarian cancers are epithelial ovarian cancers, 80% of which are serous papillary carcinomas.
* 10-15% of all ovarian cancers are hereditary in origin.

## Etiology and Risk Factors

Possible etiologies of the adenexal mass:
* Gastrointestinal tract: bowel cancer, constipation, bowel abscess
* Urinary tract: full bladder
* Obstetrical/Gynecological: pregnancy, hydrosalpinx, tubal cancer, fibroids, ovarian cancer

### Benign Ovarian Tumors

* Functional ovarian cysts arise from ovulatory failure, growth, and rupture of the graffian follicle.
* Endometriomas arise from cyclic bleeding of ectopic endometrium.
* Dermoid cysts arise from oocytes.

### Epithelial Ovarian Carcinoma

Epithelial ovarian tumors arise from the peritoneal coverings of the ovaries.
Risk factors:
* Nulliparity
* Early menarche
* Late menopause
* Age over 40
* Family history of breast, colorectal, or ovarian cancer
* BRCA 1 or 2 mutations
* Oral contraceptive use, hysterosalpingectomy, breast feeding, and tubal ligation are protective factors.

## Clinical Presentation and Diagnostic Approach
### Presentation of the Adenexal Mass

Women may present with
* Most cases are discovered incidentally and present with vague symptoms
* Postmenopausal bleeding
* Dyspareunia
* Acute pain in pelvis and lower abdomen
* Urinary frequency, urgency
* Constipation
* Bowel obstruction
* Ascites
* Omental masses
* Pleural effusion
* Local lymphadenopathy
* Palpable adenexal masses

### Diagnostic Approach to the Adenexal Mass

* Pelvic and abdominal ultrasound
** Benign disease will usually present as a mass <8cm in size, cystic in consistency, and unilateral
** Malignant disease will typically present as a mass >8cm in size, solid and cystic in consistency, and bilaterally. Furthermore, ascites, omental lesions, and enlarged lymph nodes may be visualized: all of which suggest a malignant etiology.
* CT scanning (MRI rarely used for this purpose)
* Ca-125 measurement (if required equipment)
* CBC + differential: if anemic, thorough workup should be completed for a gastrointestinal pathology.
* Creatinine
* Laparotomy and biopsy. Laparotomy is performed according to the following guidelines
** Cancer without evidence of spread: excision of lesion, omentum, and regional lymph nodes for staging
** Cancer with evidence of abdominal spread: excision of all lesions greater than 1cm
*** Typically involves a total hysterectomy, salpingectomy, oophorectomy
*** If bowel obstructed or infiltrated, small and/or large bowel resection is indicated
* Laparoscopy and biopsy if laparotomy not done.
* Percutaneous aspiration and paracentesis with cytology performed.

## Pathology, Histology, and Staging
### Ovarian Cancer

* Epithelial ovarian tumours (90% of ovarian cancer)
** Serous papillary tumors (80* of ovarian cancer)
** Mucinous
** Endometrioma (high malignant potential)/clear cell
** Mixed tumours
* Germ cell tumours
** Immature teratoma
** Dysgeminoma (produces LDH)
** Yolk sac tumors (produces AFP)
** Embryonal carcinoma (AFP and hCG)
** Choriocarcinoma (produces hCG)
* Stromal tumours
** Sertoli-Leydig (produces testosterone)
** Granulosa cell (produces estrogen)

#### Staging

Simply put
* Stage 1: confined to the ovary (survival 90% at 5yr)
* Stage 2: confined to the pelvis (survival 60-75% at 5yr)
* Stage 3: confined to the abdomen, without invasion of liver parenchyma (survival 30-40% at 5yr)
* Stage 4: invasion of liver parenchyma and/or beyond (survival 10% at 5yr)

## Management
### Functional Ovarian Cyst

* Reevaluate in 1-2 months. If no resolution in 6-8 weeks, refer to specialist.

### Ovarian Cancer

* If BRCA 1 positive, prophylactic surgery at age 35.
* If BRCA 2 positive, prophylactic surgery at menopause.
** There is approximately a 5-10% chance of finding tubal cancer at surgery.
* Stage I, Grade I-II cancer, follow postoperatively (see operative indications in Approach. All other grades and stages may only be treated with chemotherapy (Carbo/Taxol).