II. Pathophysiology
- Idiopathic destructive Thyroiditis resulting in fibrosis of Thyroid and adjacent neck
- May be associated with more generalized fibrosis
- Idiopathic Multifocal Fibrosclerosis
III. Epidemiology
- Onset age 30 to 60 years
IV. Symptoms
V. Signs
- Very firm (rock or wood-like) Thyroid swelling (Goiter)
- Hypothyroidism (30%)
VI. Labs
-
Thyroid Function Tests (T4 Free and TSH)
- Most patients are euthyroid (70%)
- Hypothyroidism (Increased Serum TSH and decreased T4 Free) in up to 30% of cases
- Antithyroid peroxidase antibodies (>60%)
-
Serum Calcium
- Hypocalcemia occurs if fibrosis affects the adjacent Parathyroid Glands
VII. Imaging
-
Radioiodine Uptake (Thyroid uptake and scan)
- Low uptake (contrast with Grave's Disease)
VIII. Diagnosis
- Thyroid biopsy
IX. Management: Tracheal or esophageal compression
- First-line
- Surgical decompression
- Other agents (no definitive treatment)
- Corticosteroids
- Mycophenolate (Cellcept)
- Methotrexate
- Tamoxifen (suppresses fibroblast proliferation)