Two cases of thyroid gland invasion by upper mediastinal carcinoma

Abstract

Summary The objective this study is to report two cases of thyroid gland invasion by upper mediastinal carcinoma. Mediastinal tumors are uncommon and represent 3% of the tumors seen within the chest. In reports on mediastinal masses, the incidence of malignant lesions ranged from 25 to 49%. The thyroid gland can be directly invaded by surrounding organ cancers. We report these cases contrasting them to the case of a thyroid cancer with mediastinal lesions. Case 1 was a 73-year-old woman who was diagnosed with papillary thyroid carcinoma, and she underwent surgery and postoperative radioactive iodine. Case 2 was a 74-year-old man who was diagnosed with non-small-cell lung carcinoma, favor squamous cell carcinoma, and he underwent chemoradiotherapy. Case 3 was a 77-year-old man who was diagnosed a thymic carcinoma based on pathological findings and referred the patient to thoracic surgeons for surgical management. The images of the three cases were similar, and the differential diagnoses were difficult and required pathological examination. Primary thyroid carcinoma and invading carcinoma originating from the adjacent organs need to be distinguished because their prognoses and treatment strategies are different. It is important to properly diagnose them by images and pathological findings. Learning points: The thyroid gland in the anterior neck can be directly invaded by surrounding organ cancers. Primary thyroid carcinoma and invading carcinoma originating from the adjacent organs need to be distinguished because their prognoses and treatment strategies are different. It is important to properly diagnose by images and pathological findings.

Treatment optimization and prognostic considerations for primary squamous cell carcinoma of the thyroid

“…Using laryngoscopy, gastroscopy, CT scan, or systemic PET-CT, the possibility of secondary thyroidal squamous cell carcinoma can be ruled out (18)(19)(20). Cellular markers such as p63, PAX8, CK7, CK19, CK20, TG, and TTF-1, can also be used to help diagnose PSCCT (5,8). In our study, all patients were diagnosed with PSCCT using histopathology which showed a palisade arrangement, intercellular bridges, and keratinization with a cancer pearl.…”

“…These PSCCT characteristics also make it difficult to achieve negative margins during radical resection of the tumor. Because of the difficulties of removing PSCCT surgically and its lack of sensitivity to radiotherapy or chemotherapy, patients with PSCCT have an extremely poor prognosis, with median survival times after diagnosis of only 5-8 months (5,6). The clinical behavior of PSCCT resembles anaplastic thyroid carcinoma, another difficult to treat tumor of the thyroid with a poor prognosis (3,7).…”

“…PSCCT has an extremely poor prognosis due to its rapid growth rate and highly invasive nature. Most patients die within a year of diagnosis and the median survival time is 5 to 8 months (3,5). The main causes of death are attributed to local recurrence and metastasis.…”

Occult Thyroid Carcinoma without Malignant Thyroid Gland Findings during Preoperative Examination: Report of Three Cases

“…However, these diagnostic procedures are difficult in ectopic thyroid glands in the mediastinum because of anatomical complexity (presence of bones and lungs). We have encountered and reported two cases of patients with mediastinal tumors that were not thyroid cancers and were diagnosed after biopsy by bronchoscopy, immunohistological examination for PAX-8, thyroglobulin, and TTF-1 [5].…”