J Pathol Transl Med.  2023 Jul;57(4):242-245. 10.4132/jptm.2023.06.16.

Intrathyroidal metastasis of tonsillar squamous cell carcinoma masquerading as a primary thyroid tumor

• Go JH

• KMID: 2544332
• DOI: http://doi.org/10.4132/jptm.2023.06.16

Abstract

Intrathyroidal metastasis of tonsillar squamous cell carcinoma is rare. To date, only six cases have been reported in the literature. This case was unusual and presented with thyromegaly before the diagnosis of the primary tumor. A 55-year-old male patient was suspected to have a primary thyroid tumor with nodal metastasis. The thyroid gland was diffusely enlarged, with no discernible mass. Histologically, the thyroid parenchyma revealed extensive endolymphatic tumor emboli, which were positive for p40 and p16 in a background of chronic lymphocytic thyroiditis. Positron emission tomography–computed tomography revealed hypermetabolic activity in the right tonsillar region. Tonsillar biopsy revealed human papillomavirus–positive squamous cell carcinoma. The present case is the first reported case of intrathyroidal metastasis of tonsillar squamous cell carcinoma with an initial clinical presentation of thyroid enlargement before the primary tumor of tonsillar cancer was diagnosed.

Keyword

Intrathyroidal metastasis; Tonsil; Goiter; Squamous cell carcinoma; Position emission tomography

Figure

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  Fig. 1. The thyroid gland is diffusely enlarged with no discernible mass.

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  Fig. 2. Histologic findings of thyroid gland. (A) The thyroid parenchyma reveals extensive endolymphatic tumor emboli in the background of chronic lymphocytic thyroiditis. (B) The tumor is composed of solid nests of atypical cells. The tumor cells are positive for p16 (C) and p40 (D).

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  Fig. 3. Histologic findings of tonsil. (A, B) Tonsillar biopsy shows squamous cell carcinoma. The tumor cells are positive for p16 (C) and p40 (D).

Reference

References

1. Jankowska P, Teoh EM, Fisher C, Rhys Evans P, Nutting CM, Harrington KJ. Case report: isolated intrathyroid metastasis from undifferentiated and squamous carcinoma of the head and neck: the case for surgery and re-irradiation. Br J Radiol. 2008; 81:e154–61.

2. Scanelli G, Aimoni C, Marchetti E, Geminiani M, Pastore A. Thyroid’s metastasis of tonsillar squamous cell carcinoma. Recenti Prog Med. 2005; 96:428–30.

3. Millare GG, Kwon M, Edeiken-Monroe BS, Debnam JM. (18)FPET/CT imaging of metastasis to the thyroid gland: Imaging findings and effect on patient management. J Solid Tumors. 2017; 7:7–13.

4. Gumaa D, Christakis I, Mihai R. Metastasis to the thyroid gland from a tonsil squamous cell carcinoma. AME Case Rep. 2018; 2:7.

5. Aparici CM, Win AZ. Two cases of thyroid metastasis from head and neck squamous cell carcinoma detected by FDG-PET/CT. J Clin Imaging Sci. 2014; 4:62.

6. LeRose CC, Ramirez CA. Atypical metastasis of p16-positive tonsillar squamous cell carcinoma to the pleura: a case report. J Oral Maxillofac Surg. 2018; 76:2577–81.

7. Khan S, Anichini G, Mian A, Kareem H, Syed N, O’Neill K. Tonsillar carcinoma spreading metastases to central nervous system: case report and literature review. J Neurol Surg Rep. 2021; 82:e11–6.

8. Di Maio P, Iocca O, De Virgilio A, et al. Role of palatine tonsillectomy in the diagnostic workup of head and neck squamous cell carcinoma of unknown primary origin: a systematic review and meta-analysis. Head Neck. 2019; 41:1112–21.

9. Sacks R, Law JY, Zhu H, et al. Unique patterns of distant metastases in HPV-positive head and neck cancer. Oncology. 2020; 98:179–85.

10. Chernock RD, Lewis JS. Approach to metastatic carcinoma of unknown primary in the head and neck: squamous cell carcinoma and beyond. Head Neck Pathol. 2015; 9:6–15.