[From Hashimoto thyroiditis to B-cell lymphoma of the thyroid gland]

Lymphoma of the thyroid gland is an uncommon condition occurring primarily in older women. Most patients have a short history of an enlarging thyroid or a neck mass causing tracheal compression. There is also a strong association between thyroid lymphoma and Hashimoto's thyroiditis. The diagnosis is established by biopsy. The conventional approach to treatment is combination of radiation therapy with multi-agent chemotherapy, while there is no significant role for extirpative surgery in the management of thyroid lymphoma. The prognosis of localised tumours (stage IE, Ann Arbor classification) is excellent. Extrathyroidal involvement (stage IIE-IVE) reduces the 5-year survival rate to about 70%, provided that current therapy regimens are respected. In this case report, the different stages of development from Hashimoto's thyroiditis to thyroid lymphoma are demonstrated by histology. In a review of the literature we discuss the diagnostic procedure and the current approach to treatment.