occult primary malignancy

occult primary malignancy

Occult cancer, unknown primary A malignancy of unknown 1º site or origin that is symptomless, which first manifests itself as metastases or secondary–paraneoplastic phenomena, and usually has a poor prognosis; OPMs are problematic as appropriate therapy requires that the primary malignancy be eradicated, and many remain obscure despite aggressive diagnostic work-up; certain malignancies metastasize to certain sites with greater than expected frequency; in OPMs affecting the brain, the primary arises in the lungs in up to 85% Treatment Up to 30% of Pts with metastases from an occult primary adenoCA may respond to chemotherapy–mitomycin C, adriamycin, vincristine; poor response is more common in ♂ and in Pts with liver and/or infradiaphragmatic metastases

Occult primary malignancies

Bone Breast, bronchus, prostate, thyroid, kidney

CNS Breast, bronchus, kidney, colon

Head & neck Oropharynx, nasopharynx–most are squamous cell carcinoma;  also adenocarcinoma, melanoma, rhabdomyosarcoma, oat cell, salivary  gland, thyroid carcinomas

Liver CA of stomach, colon, breast, pancreas, or bronchus

Lung Breast, colon, kidney, melanoma, sarcoma, stomach, testis, thyroid

Lymph nodes

• Cervix  Naso– and oropharynx, thyroid, larynx, lymphoma

• Supraclavicular  Bronchi, breast, stomach, esophagus, pancreas, colorectal,
lymphoma

• Axillary  Breast, melanoma, lymphoma

• Inguinal  Urogenital tract, anus, melanoma, lymphoma

Ovary Stomach, colon

Serosal surfaces Bronchi, breast, ovary, lymphoma

Skin Melanoma, breast, bronchus, stomach, kidney  

McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.