Sub-acute thyroiditis and hepatitis in a case of infectious mononucleosis.

A viral aetiology for sub-acute (de Quervain's) thyroiditis has long been postulated although proof has been elusive. Infectious mononucleosis has been associated with sub-acute thyroiditis in only two papers, and histological evidence of sub-acute thyroiditis was lacking in both. A case of sub-acute thyroiditis, confirmed by histology, occurring in a patient with infectious mononucleosis is now reported.