Occult primary tumor

Occult primary tumor is a term used in oncology to describe a situation where metastatic cancer cells are identified, but the location of the primary tumor remains unknown, despite extensive diagnostic procedures. This condition is also known as cancer of unknown primary (CUP) or unknown primary cancer.

Epidemiology

Occult primary tumors account for approximately 3-5% of all malignant neoplasms. They are more common in older adults, with the median age at diagnosis being around 60 years. Both men and women can be affected, with a slightly higher incidence in men.

Pathophysiology

The exact pathophysiology of occult primary tumors is not fully understood. It is believed that the primary tumor may undergo necrosis and disappear, leaving only the metastatic sites. Alternatively, the primary tumor may still be present but too small to be detected by conventional diagnostic methods.

Diagnosis

The diagnosis of an occult primary tumor is challenging and involves a thorough medical history, physical examination, and a variety of diagnostic tests. These may include blood tests, imaging studies, and biopsies. Despite these efforts, the primary tumor may remain undetected.

Treatment

The treatment of occult primary tumors is largely dependent on the location and type of the metastatic cells. Treatment options may include surgery, radiation therapy, chemotherapy, hormone therapy, or a combination of these. The prognosis varies widely, depending on factors such as the type and location of the metastases, the patient's overall health, and the response to treatment.

See also

• Cancer
• Metastasis
• Oncology