Investigation strategy in the management of metastatic adenocarcinoma of unknown primary presenting as cervical lymphadenopathy.

Conclusion: Computed tomography (CT) of the neck, chest, abdomen and pelvis is the most appropriate initial investigation following a fine needle aspiration cytology (FNAC) diagnosis of metastatic adenocarcinoma in cervical lymph nodes with unknown primary. PET-CT should be considered as the next step if the initial CT fails to identify the primary site, but its true value is yet to be determined.

Objective: To review investigation strategies for metastatic adenocarcinoma of unknown primary presenting as cervical lymphadenopathy, and to develop a management algorithm.

Methods: This was a retrospective case note study from two regional head and neck cancer centres in the UK. Adult patients with FNAC diagnosis of metastatic adenocarcinoma in cervical lymph nodes between 1998 and 2008, with a minimum 5-year follow-up, were included. Patients with a clinically obvious primary tumour or a previous history of adenocarcinoma were excluded.

Results: This study examined 41 cases. CT of the neck, chest, abdomen and pelvis was the most useful initial investigation. It identified the primary tumour site in 16/28 cases (57%), detected the primary tumour and led to revision of the FNAC diagnosis in 1 case (2.4%), and was necessary for the final diagnosis of true unknown primary in 12 cases (29.3%). Targeted imaging was not helpful.