Inclusion Criteria:  

• Patient presenting to a General Internal Medicine Service.
• Patient in one of the 3 Mayo Clinic Campuses (Rochester, Arizona, Florida).
• Patient with an undiagnosed mass: New or enlarging lymph nodes clinically or on imaging:
  • New mass on imaging of soft tissues, bone, spleen, adrenal gland, retroperitoneum, or intraabdominal location without clear organ association.
• Patient has understood and signed the informed consent to participate in the registry.
• Patient has the ability to complete all aspects of registry enrollment.
• Aged 18 and older.

 Exclusion Criteria:   

• Mass involving the breast, brain, kidney, lung, ovary/adnexa, liver, pancreas, sinus, throat, or thyroid gland will be addressed by the respective specialty areas.  
• Patients with a known history of any condition or factor judged by the investigator to preclude participation in the registry or which might hinder adherence.
• Lacking the capacity to consent.
• Prisoners or institutionalized individuals.
• Pregnant women.

Eligibility last updated 9/17/21. Questions regarding updates should be directed to the study team contact.