Gamma-chain heavy-chain disease with primary thyroid plasmacytoma

A case of gamma-chain heavy-chain disease was associated with primary thyroid plasmacytoma. The patient has been free of complaints for two years since the removal of the tumorous thyroid. The heavy-chain fragment (molecular weight, 32,000 daltons) has disappeared from the serum and urine, while the previously low levels of normal immunoglobulins have increased. The immunoglobulin anomaly may be correlated with the chronic antigen stimulus.