Extensive screening for primary tumor is redundant in melanoma of unknown primary

For decades, patients in our institution with metastastic melanoma of unknown primary have been subjected to extensive examinations in search of the primary tumor. This retrospective study questions the results, and thus the feasibility of these examinations. Of 103 patients diagnosed with unknown primary tumor during the period 1986-2006, 39 (38%) presented primarily with a cutaneous or a subcutaneous metastasis, and 63 (61%) with a lymph node metastasis. One patient presented with a bone metastasis (1%). Eighty-seven patients (84%) were examined by an ophthalmologist. A choroidal melanoma was suspected as the primary tumor in one patient. Eighty-four patients (82%) were examined by an oto-rhino-laryngologist, whereby no primary tumor was found. Ninety-five patients (92%) were examined by sigmoideoscopy/rectoscopy. No primary tumor was found. Of the 36 women, 32 had a gynecological examination (89%), revealing no primary tumor. We conclude, that only one possible (but not verified) primary tumor was disclosed by various specialists examinations of 103 patients referred with the diagnosis metastatic melanoma with no primary tumor. Special screenings can thus be considered as redundant. Thus, for patients referred with metastastic melanoma of unknown primary, we recommend that a detailed history is obtained, and a standard physical examination performed, in addition to a histopathological review and CT/PET for staging.