Diagnosis and management of carcinoma of unknown primary in the head and neck.

Carcinoma of unknown primary is defined as the histological diagnosis of metastasis without the detection of a primary tumor. In the literature, the incidence of CUP in all patients with a malignant disease is said to be between 3% and 15%. The most frequent histopathological results of CUP metastases are adenocarcinoma, followed by undifferentiated carcinoma and squamous cell carcinoma. In this retrospective investigation the clinical records of 167 patients were studied. All patients had been admitted and treated for cervical CUP at the Department of Otorhinolaryngology of the Grosshadern Clinic from 1979 to 1998. Cervical swelling was the first noted symptom in all cases, followed by pain and dysphagia. The study group comprised 134 men and 33 women with an average age of 55 years at admission. Squamous cell carcinoma (n=123) was the predominant histopathological finding of the cervical lymph nodes. During the 10-year follow-up, a primary tumor was detected in 36 (21.5%) of the 167 initially diagnosed CUP patients. In over 90% of these cases the tumor was localized in the head and neck region. The most frequent origin of the tumor was the tonsilla palatina (n=7). Neck dissection and additional postoperative radiotherapy was performed in 118 (70.7%) of the 167 CUP patients. Primary radiotherapy was the treatment of choice in 28 patients; eight patients received combined radio-chemotherapy as the primary treatment and seven patients were treated with chemotherapy alone. Six patients had no treatment. Comparison of different treatment protocols revealed a significant difference in patient survival: in comparison with primary radiotherapy alone or neck dissection and postoperative radiotherapy, the survival rate improved significantly in patients that received a bilateral tonsillectomy in addition to neck dissection and postoperative radiotherapy. The 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. Bilateral tonsillectomy is especially important and is correlated with a significant improvement of the survival rate in CUP patients. Additional postoperative radiation of the entire pharyngeal and laryngeal mucosa should also be considered in order to treat a possible small primary tumor in this region.