Cribriform adenocarcinoma of the tongue: a hitherto unrecognized type of adenocarcinoma characteristically occurring in the tongue

Aims: We report a review of our institutional and consultation files in ord er to select cases of hitherto unrecognized type of adenocarcinoma occurrin g in the tongue. Materials and results: Eight cases of a characteristic adenocarcinoma of th e tongue resembled solid and follicular variants of the papillary carcinoma of the thyroid. All the tumours were unencapsulated and were divided by fi brous septa into lobules. Major parts of the lesions were composed of areas with solid and microcystic growth patterns. The most striking cytological feature was that the tumour nuclei were pale-staining with a 'ground glass' quality, and they often appeared to overlap. Immunohistochemically, the tu mours expressed cytokeratin and S100 protein and, focally, actin; thyroglob ulin was negative. Ultrastructurally the cells had clefted nuclei, and the cytoplasm contained a few mitochondria, lysosomes and Golgi apparatus. Many tumour cells had combined features of both myoepithelial and secretory dif ferentiation-well formed microvilli on their apical borders and bundles of microfilaments. At first presentation, all eight patients had metastases in the regional neck lymph nodes, but all are alive 2-6 years after the initi al excision and irradiation. Conclusion: We describe a distinctive type of adenocarcinoma of the tongue, for which we propose the name cribriform adenocarcinoma of the tongue (CAT ). CAT usually presents with metastases in the neck lymph nodes at the time of presentation. We hypothesize that the tumour might arise from the thyro glossal duct anlage.