Spindle epithelial tumor with thymus-like differentiation of the thyroid in a 70-year-old man

Abstract

Spindle epithelial tumor with thymus-like differentiation (SETTLE) is a very rare tumor of the thyroid gland mostly occurring in young patients. The imaging findings of SETTLE tumors are yet to be defined. However, they are usually described as well-defined heterogeneously enhanced masses on CT scan. The current case has the potential growth as compared with a 2009 chest radiography. We took into account the possibility of SETTLE in the case of a bulky mass in patients over 70 years old, particularly in the lower neck. Herein, we report a case of the oldest patient so far. The patient underwent a right lobectomy of the thyroid and mass excision. Follow-up CT scans after 6 months revealed no local recurrence. Surgery is the gold standard treatment for SETTLE. Chemotherapy and radiotherapy could be another possible option for patients with advanced stage SETTLE.

Spindle Epithelial Tumor With Thymus-Like Differentiation (SETTLE) Misdiagnosed as Papillary Thyroid Carcinoma: A Case Report

“…Another striking feature observed in our case on IHC was the positivity for HMWCK exhibited by the tumor cells (Figures 3b, 3c) as it may be evidence to suggest an origin from the remnants of the ultimobranchial body. There are a few studies wherein these clinical, histopathological, and immunohistochemical characteristics have been recorded, and the findings from our report are consistent with existing literature [3][4][5][6][7]9].…”

“…Moreover, the lack of specific molecular markers for SETTLE makes this ancillary mode of testing unreliable [5]. It is mainly immunohistochemistry (IHC; positivity for cytokeratin (CK) and vimentin and negativity for thyroid markers such as thyroglobulin and TTF1) that provides sufficient evidence to establish a diagnosis of SETTLE [4]. This necessitates a thorough understanding of this rare entity to aid in the accurate diagnosis of the condition and to prevent the misdiagnosis of thyroid carcinomas.…”

“…It has previously been published under the titles of “thyroid thymoma,” “malignant teratoma,” and “thyroid spindle cell tumor” [ 3 ]. Although surgery is the primary mode of management, chemotherapy and radiotherapy are also used in advanced cases [ 4 ].…”

“…There is paucity in the literature and no hallmark finding to differentiate SETTLE from other tumors by noninterventional modes of testing such as ultrasonography (USG). Fine needle aspiration (FNAC) biopsy for SETTLE shows variable cytological features and the lack of specificity for diagnosing a case of SETTLE [ 4 ]. Moreover, the lack of specific molecular markers for SETTLE makes this ancillary mode of testing unreliable [ 5 ].…”

Spindle epithelial tumor with thymus‐like differentiation in fine needle aspiration of thyroid gland: Report of two cases

“…SETTLE has an indolent course and the potential of delayed metastasis. Unusual presentations started to emerge, including cases with metastasis at the time of initial diagnosis, 2,3 cases with rapid progression, 3 and cases described in late adulthood 4 . The clinical diagnosis is difficult since there is no specific serum marker for diagnosis.…”