International Journal of Physical Medicine & Rehabilitation
Open Access

Abstract

Riedel's Thyroiditis Presenting as Rapidly Progressive Hypothyroidism: A Case Report and Literature Review

Jeffrey Boakye, Zeng Francine R, Malchoff Carl, Appel Elizabeth, Niranjan Varalakshmi, Mortensen Eric, Millar Danielle, Narinder Maheshwari*

Objective: Riedel’s Thyroiditis (RT) is a rare thyroid pathology that presents a challenge for clinicians to diagnose and treat. Its etiology remains unknown, although data suggests an association with Hashimoto thyroiditis, systemic fibrosis, and IgG-4 related systemic disease. Due to its rarity, there is no consensus on treatment. We present a case of progressive hypothyroidism and a rapidly growing thyroid mass prior to diagnosis of RT.

Methods: Laboratory investigations included Thyroid Stimulating Hormone (TSH), free T4, Anti-Thyroid Peroxidase (TPO) and Anti-Thyroglobulin (TG) antibodies, IgG, Parathyroid Hormone (PTH), calcium, and calcitonin levels. Imaging included thyroid ultrasound and chest Computed Tomography (CT). Following fine needle aspiration and core biopsy, immunostaining and flow cytometry were performed.

Results: A 36-year-old woman presented with rapidly progressive neck swelling and progressive hypothyroidism requiring several Levothyroxine dosage increases over a one year span. TSH was 17.40 uU/mL (ref: 0.35-4.94 uU/ mL), with a normal T4 while on 150 mcg of levothyroxine. Elevated thyroid autoantibodies (Anti-TPO >700 IU/mL, ref: 0.0-9.0 IU/mL, Anti-TG >2000 IU/mL, ref: 0.0-4.0 IU/mL), with remaining labs normal. Thyroid ultrasound and CT of the chest demonstrated an enlarged, irregular thyroid gland with tracheal deviation and a nodular like area off the posterior aspect of the mid thyroid. She was diagnosed with RT after biopsy and managed medically with Prednisone and Tamoxifen.

Conclusion: Because hypothyroidism is a common diagnosis, especially compared to the rare RT, it is easy for the diagnosis of RT to be delayed until the thyroid mass impinges on adjacent structures. This report highlights how a high index of suspicion is required for diagnosis and the difficulty of treatment due to varying responses and side effects.

Published Date: 2025-01-22; Received Date: 2023-07-20