Carcinoma of unknown primary origin (CUP) describes a metastatic disease for which the primary cancer cannot be identified. Of all invasive malignancies, 2% to 6% are CUP. The most common tumor associated with CUP is adenocarcinoma. Squamous cell carcinoma and undifferentiated neoplasms make up a smaller portion of CUP. When a pathologic diagnosis is established, additional evaluation should be tailored according to the patient’s risk factors (eg, smoking and breast cancer risk), symptoms and signs, sites of metastasis, and the histologic diagnosis.
Pineal Gland Metastasis From Poorly Differentiated Carcinoma of Unknown Primary Origin
