[Medullar cancer of the thyroid associated with dermal mucinosis].

INTRODUCTION: Dermal mucinosis can be associated with numerous pathologies, in particular involving the thyroid, but has never been described in the case of a medullar cancer of the thyroid (MCT).

CASE-REPORT: A 69-year-old man consulted for a facial erythrosis, which had been developing for a few weeks without any identified triggering factor. The skin biopsy showed dermal mucinosis and tests revealed a sporadic medullar cancer of the thyroid with secondary bone, ganglion and medullar localizations.

DISCUSSION: The association between medullar cancer of the thyroid and dermal mucinosis has never been described. Several hypotheses may explain this: the thyroid pathology itself, whatever its nature, the capacity of the MCT to synthesize mucin and the medullar metastatic overgrowth.