J Yeungnam Med Sci.  2024 Oct;41(4):312-317. 10.12701/jyms.2024.00556.

A 32-year-old man with plexiform schwannoma of the thyroid gland: a case report

• Park IR
• Kim MC
• Chung SM
• Song SY

• KMID: 2560493
• DOI: http://doi.org/10.12701/jyms.2024.00556

Abstract

Plexiform schwannomas representing a rare subset, comprise 5% of all schwannomas. However, their occurrence in the thyroid gland is exceptionally rare. A 32-year-old male presented with an incidentally discovered, asymptomatic thyroid mass. Imaging revealed an approximately 5 cm heterogeneous solid mass on the right thyroid lobe extending to the upper mediastinum and directly invading the upper trachea. Under the suspicion of thyroid malignancy, the patient underwent right thyroidectomy. Histological examination confirmed a plexiform schwannoma with S100-positive spindle cells. Currently, the patient is undergoing outpatient follow-up, with no reported complications. To our knowledge, this is the first documented case of plexiform schwannoma of the thyroid gland within the English literature. This case highlights the diverse and unpredictable clinical manifestations of thyroid masses, emphasizing the importance of a multidisciplinary approach for diagnosing and managing rare entities, such as thyroid gland schwannomas.

Keyword

Head and neck neoplasms; Plexiform schwannoma; Schwannoma; Thyroid mass; Thyroid schwannoma

Figure

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  Fig. 1. Thyroid ultrasound. (A) Transverse and (B) longitudinal views reveal a right thyroid mass measuring 3.23×2.54×6.04 cm, characterized by a solid, heterogeneous, and hypoechoic appearance with irregular margins. No cervical lymphadenopathy is visible.

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  Fig. 2. Neck computed tomography image reveals a lobulated low-density mass approximately 5 cm in size in the inferior portion of the right thyroid gland, extending to the upper mediastinum, and direct invasion of the upper trachea, causing luminal narrowing. No enhancement is visible in the mass (A) before and (B) after contrast administration.

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  Fig. 3. Magnetic resonance imaging shows a right thyroid mass. (A) Hypointense signal on coronal T1-weighted images. (B) Hyperintense signals on coronal T2-weighted images without a target sign.

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  Fig. 4. Gross and histologic findings of the resected specimen. (A) Gross appearance of the resected specimen shows a multinodular yellowish mass adjacent to the thyroid gland. (B) Low-power microscopic examination reveals a poorly encapsulated mass with a tongue-like projection into the thyroid gland (hematoxylin and eosin [H&E] stain, ×10). (C) The tumor cells have spindled, wavy, and tapering nuclei. Typical Verocay bodies, formed by two rows of nuclear palisading separated by eosinophilic fibrillary cell processes, are present (H&E stain, ×100). (D) Tumor cells exhibit diffuse positivity for S100 protein (immunohistochemical stain, ×100).

Reference

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