title: Infiltrative thyrotoxicosis: an unusual case of diffuse large B cell lymphoma.
abstract: Thyrotoxicosis is most commonly caused by Graves' disease, toxic multinodular goitre, a functioning thyroid adenoma, or thyroiditis. Extrinsic infiltrative conditions affecting the thyroid gland are typically destructive, and associated with thyroid hypofunction. We describe the case of a 61-year-old woman who presented to our hospital with symptoms of thyrotoxicosis, neck swelling and thyroid function tests consistent with hyperthyroidism. An ultrasound revealed a multinodular goitre with retrosternal extension, but CT imaging suggested thyroid gland infiltration, with cervical lymphadenopathy. An excisional lymph node biopsy confirmed the diagnosis of diffuse large B cell lymphoma causing infiltrative thyrotoxicosis. Treatment with six cycles of Rituximab-CHOP lead to rapid normalization of symptoms, imaging, and thyroid function.
authors.affiliation: Specialist Registrar in Medical Oncology, University Hospital Limerick , Limerick , Ireland.
authors.forename: Michael T
authors.initials: MT
authors.lastname: McCarthy
authors.affiliation: Senior House Officer in General Medicine, University Hospital Limerick , Limerick , Ireland.
authors.forename: Michael
authors.initials: M
authors.lastname: Keyes
authors.affiliation: Consultant Endocrinologist, University Hospital Limerick , Limerick , Ireland.
authors.forename: James
authors.initials: J
authors.lastname: O'Hare
authors.affiliation: Consultant ENT Surgeon, University Hospital Limerick , Limerick , Ireland.
authors.forename: Neville
authors.initials: N
authors.lastname: Shine
authors.affiliation: Consultant Medical Oncologist, University Hospital Limerick , Limerick , Ireland.
authors.forename: Rajnish K
authors.initials: RK
authors.lastname: Gupta
keywords: hyperthyroidism; infiltrative thyrotoxicosis; lymphoma