Venn Biosciences Corporation ("InterVenn") has developed a liquid biopsy that is capable of distinguishing benign from malignant masses in women presenting with adnexal (pelvic) masses, through a simple blood test. The underlying technology combines mass spectrometry and artificial intelligence/machine learning to analyze tumor-associated changes in circulating glycoproteins.

The purpose of this study is to prospectively collect de-identified biological samples and data from women with a known pelvic mass, in order to validate ovarian cancer specific glycoproteomic signatures in the blood based on histologically confirmed malignancy status of the mass.

This is a prospective, international, multi-center, observational study with a goal of collecting de-identified samples and data from 1,200 women with a known pelvic mass. Participants will consent to baseline and follow-up data and biospecimen collections.

Inclusion Criteria:

• Women age 18 years or older
• Able to provide a written informed consent and who understand and agree to all study procedures required
• A newly diagnosed adnexal mass as confirmed by imaging (computed tomography, ultrasonography, or magnetic resonance imaging) prior to enrollment
• Planned diagnostic procedure or surgery by the subject's physician to remove adnexal masses within 90 days of imaging. (Note that diagnostic procedure typically includes biopsy (needle core or laparoscopic-directed), ascites cytology, pleural effusion cytology or FNA)

Exclusion Criteria:

• Had/Has a diagnosis of invasive malignancy (exception: non-melanoma skin cancers) in the previous 5 years.
• Currently receiving or ever received any of the following prior cancer therapies in the previous 5 years. This includes curative surgical resection, local or systemic chemotherapy, targeted therapy, immunotherapy including cancer vaccines, hormone therapy, and/or radiation therapy.
• Pregnancy
• Current febrile illness
• Acute exacerbation or flare of an inflammatory condition requiring escalation in therapy
• Recipient of organ transplant
• Poor health status or unfit to tolerate blood draw

In addition, this study will include a small subgroup of women with a newly diagnosed clinically benign adnexal mass(es) for whom surgery is not planned as determined by the treating physician. This subgroup will follow the same exclusion criteria as listed above.

Per eligibility, individuals must have a known adnexal mass (pelvic mass).

Adult women who present with a known adnexal mass as described in the study inclusion and exclusion criteria.