Final answer:
The presence of a complex ovarian mass and an irregular endometrial stripe most likely points to ovarian carcinoma. Simple cysts differ in appearance on ultrasounds, and the irregular stripe could suggest related endometrial pathology. Laparoscopy is the definitive method for diagnosing conditions like endometriosis.
Step-by-step explanation:
The most likely diagnosis for a patient with a 10-cm, complex left ovarian mass and an irregular endometrial stripe on pelvic ultrasound would be ovarian carcinoma. Ovarian cysts are generally simple structures filled with fluid, whereas a complex mass suggests the presence of solid areas, septations, or cysts within a cyst, indicative of a potential malignancy. Furthermore, an irregular endometrial stripe could be associated with endometrial involvement by the ovarian carcinoma or could suggest a secondary pathology like endometrial hyperplasia or carcinoma. Uterine fibroids typically present as well-defined, solid masses in the uterus and are less likely to be confused with an ovarian mass on ultrasound imaging.
Diagnosing Endometriosis
For conditions like endometriosis, a definitive diagnosis can be achieved through laparoscopy, which is a surgical procedure involving the insertion of a camera through the abdominal wall to visually inspect the abdomen for endometrial growth.