Editing Thyroiditis (section)

=== '''Riedel's     thyroiditis''' ===

** Extremely rare chronic      idiopathic inflammatory disease - inflammation followed by fibrosis of      thyroid and adjacent structures
** Associations
*** 1/3 of patients have       fibrosis elsewhere
*** PSC
*** Orbital pseudotumour
*** Autoimmune diseases       including Addison's/diabetes
** Presentation
*** Enlarging, tender goitre
*** Patients often suspected of       having anaplastic carcinoma
*** Rock hard fixed neck mass
*** Often have clinically       significant airway obstruction, dysphagia and dysphonia
** Workup
*** TSH - generally high
*** Serum calcium
*** USS. FNA is often       impossible due to hardness of mass!
*** CT CAP to look for fibrosis       elsewhere and evaluate the rock-hard neck mass
*** Definitive diagnosis       requires open biopsy - distinguished from thyroid cancer with       immunohistochemistry
*** Isthmusectomy can relieve       obstruction
** Management
*** Often end up requiring       surgery to exclude anaplastic cancer, or to treat obstructive symptoms
*** Surgery very challenging       due to obliteration of planes and landmarks
*** Resect only the necessary       segments to achieve the operative goal
** Prognosis
*** May stabilise, resolve       spontaneously, or progress over time
*** Treat with high-dose       corticosteroids
*** Tamoxifen reduces goitre       size
*** Will need levothyroxine
*** Rituximab may help
*** May need to treat       hypoparathyroidism
*** No increased risk of       thyroid cancer