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 order to select cases of hitherto unrecognized type of adenocarcinoma occurring in the tongue.

MATERIALS AND RESULTS

Eight cases of a characteristic adenocarcinoma of the tongue resembled solid and follicular variants of the papillary carcinoma of the thyroid. All the tumours were unencapsulated and were divided by fibrous 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 tumours expressed cytokeratin and S100 protein and, focally, actin; thyroglobulin 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 differentiation-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 initial 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 thyroglossal duct anlage.