Plasma cell granuloma of the thyroid associated with Hashimoto's thyroiditis.

A patient was diagnosed with plasma cell granuloma (PCG) of the thyroid associated with a fibrous variant of Hashimoto's thyroiditis (HT), after total thyroidectomy. Immunoperoxidase staining of the mass in the left lobe revealed polyclonal lambda and kappa chains. A literature search was conducted to determine other cases of such an association. Five other cases of PCG of the thyroid were found in the literature. None of them was associated with HT. This case-report confirms the possible association of HT with either plasmacytoma or PCG, previously only hypothesised.