RESUMEN
BACKGROUND: Carcinoma of unknown primary is defined as histological diagnosis of metastasis without diagnosis of a primary tumor. The incidence of CUP is stated in the literature between 3 % and 15 % of all patients with an malignant disease. Histological examination of CUP-metastasis of the neck most frequently shows a squamous cell carcinoma. A retrospective study of patient data was undertaken. PATIENTS AND METHODS: The study included 167 patients admitted and treated for cervical CUP at the department of Oto-Rhino-Laryngology, Klinikum Grosshadern from 1979 to 1998. Cervical swelling was the first noted symptom in all cases. Other symptoms were pain and dysphagia. Of the 167 patients 134 were men and 33 were women. The average age at admission was 55 years. In the studied collective squamous cell carcinoma had the highest incidence (n = 123). During the 10 year follow-up a primary tumor was found in 36 of the 167 initially diagnosed CUP-patients. In over 90 % of these cases the tumor was localized in the head and neck region. The origin of the tumor was most frequently the tonsilla palatina (n = 7). Of the 167 patients included in the study 118 patients (70,7 %) underwent surgery and additional postoperative radiotherapy. Primary radiotherapy was the treatment of choice in 28 patients, 8 patients received combined radio-chemotherapy as primary treatment and 7 patients were treated with chemotherapy alone. No treatment was performed in 6 patients. RESULTS: By comparing the treatment methods there was a significant difference of patient survival in regard to the treatment. Patients treated according to treatment-plan II, which includes an additional "diagnostic" tonsillectomy, is significantly higher than that of patients simply undergoing neck dissection and postoperative radiotherapy or primary radiotherapy alone. Treatment of choice in patients with cervical CUP should be a surgical procedure including radical neck dissection and diagnostic bilateral tonsillectomy followed by postoperative radiation of the cervical lymph drainage. DISCUSSION: Bilateral tonsillectomy is especially important and is correlated with a significant improvement of the survival rate in CUP patients. Additional postoperative radiation of the pharynx from the base of the skull to the upper oesophagus should also be considered, in order to treat a possible--small--primary tumor in this region.