Metastatic adenocarcinoma to the cervical lymph node: a significant proportion of cholangiocarcinoma in Thai patients.

OBJECTIVE: To determine distribution of the primary site of metastatic adenocarcinoma to the cervical lymph node in Thai population with histological correlation. MATERIALS AND METHODS: 72 Thai patients with metastatic adenocarcinoma to the cervical lymph node were retrospectively analyzed. Results: Thyroid gland (papillary carcinoma) was the commonest source of tumor (41%), followed by lung (25%), bile duct (17%) and breast (7%). Metastatic cholangiocarcinoma typically produced distinct glandular pattern, and frequently involved the right supraclavicular lymph node. Brush border of the gland-forming tumor cells was a consistent finding in metastatic cholangiocarcinoma, with 100% sensitivity and 97% specificity. CONCLUSIONS: Cholangiocarcinoma represents a significant portion of primary tumor in Thai patients with cervical nodal metastasis. This figure may hold true for countries where bile duct malignancy is endemic, and may be of clinical usefulness in identification of primary cancer.