Riedel's thyroiditis is a rare form of thyroiditis characterized by the replacement of normal thyroid tissue with dense fibrosis that invades the surrounding structures of the neck. It is caused by an inflammatory process that infiltrates muscles and causes compressive symptoms. Diagnosis involves ruling out other types of thyroiditis through thyroid antibody tests and often biopsy. Treatment focuses on resection for severe compressive symptoms and use of tamoxifen, methotrexate, steroids, and thyroid hormone replacement for hypothyroidism. It is important to properly diagnose this rare condition to determine the appropriate treatment.

1. BY SHALVIN ABISEKH NAND
20180571
MBBS YR 2

2. CONTENTS
• Introduction
• History
• Pathophysiology
• Symptoms
• Complications
• Differential diagnosis
• Diagnosis
• Treatment
• Conclusion
• Reference

3. WHAT IS IT?
• Riedel thyroiditis (fibrous thyroiditis, RT) is a rare form of thyroiditis
leading to a gradual parenchymal transformation to connective tissue
causing compression and fibrosis of adjacent tissues
• It affects adjacent structures as the parathyroid glands, musculature in
the neck and cause vocal cord paralysis.
• It may be associated with fibrosis in other sites in the body, such as the
retroperitoneum, and appears to be another manifestation of a systemic
autoimmune IgG4-related disease, which is associated with fibrosis
and tissue infiltration by plasma cells producing IgG4

4. HISTORY
• It is named after Bernhard Riedel.
• In 1883 he first recognized the disease and later
in year 1896 published its description.

6. PATHOPHYSIOLOGY
• It is characterized by a replacement of the normal thyroid parenchyma
by a dense fibrosis that invades adjacent structures of the neck and
extends beyond the thyroid capsule.
• This process makes thyroid gland stone-hard and fixed to adjacent
structures.
• The inflammatory process infiltrates muscles and causes symptoms of
tracheal compression.

7. SYMPTOMS
• Hard, palpable goiter, which could cause
pain(usually painless)
• Rapidly growing thyroid mass
• Compressive symptoms

8. COMPLICATIONS
• Airway obstruction
• Dysphonia
• Hoarseness
• Hypothyroidism
• Hypoparathyroidism

9. DIFFERENTIAL DIAGNOSIS
• De Quervain thyroiditis
• Goiter
• Hashimoto thyroiditis
• Thyroid lymphoma
• Anaplastic carcinoma
• Thyroditis, subacute

10. DIAGNOSIS
• Thyroid antibodies present in 2/3
• Biopsy often needed

11. TREATMENT
• Resection for compressive symptoms if severe
• Tamoxifen, methotrexate and steroids
• Thyroid hormone for hypothyroidism

12. CONCLUSION
• Riedel thyroiditis is a rare type of thyroiditis and often misdiagnosed.
Thus it is important to differentiate between different types of
thyroiditis for proper diagnosis.

13. REFERENCE
• KUMAR, V., ABBAS, A. K., ASTER, J. C., & ROBBINS, S. L.
(2013). Robbins basic pathology. Philadelphia, PA, Elsevier/Saunders.
• BRS Pathology
• https://www.researchgate.net/publication/322778584_Riedel's_thyroid
itis_clinical_presentation_treatment_and_outcomes
• https://www.ncbi.nlm.nih.gov/books/NBK537303/
• https://www.slideshare.net/drpradeeppande/thyroiditis-54573277
• https://emedicine.medscape.com/article/125243-overview