Management and Prognostic Factors for Thyroid Carcinoma Showing Thymus-Like Elements (CASTLE): A Case Series Study

Abstract

Introduction: This study aims to identify the prognostic factors that influence therapeutic modalities for thyroid carcinoma showing thymus-like elements (CASTLE).Materials and Methods: Reported studies with CASTLE patients published between 2004 and 2018 were retrieved from a cross-database literature search. Three patients treated in our institute were also included as one case series. Standardized data collection was performed; data pertaining to clinical stages, treatment regimens, and survival time were collected and statistically analyzed.Results: Up to 26 case series of CASTLE were selected, including 51 males and 38 females with a median age of 48 years. Follow-up time ranged from 2 to 362 months and the median survival time was 158.03 months. Lymph node metastasis and tumor invasion of adjacent tissue both showed a significant negative effect on survival (p = 0.001 and 0.013, respectively). Radiotherapy significantly improved survival (p = 0.034), while neck dissection significantly prolonged survival only in patients with extrathyroidal extension (p = 0.043).Conclusions: Extrathyroidal infiltration and nodal metastasis are important factors in cancer outcomes. Radiation therapy appears to be important for better outcomes in CASTLE patients, and neck dissection is recommended for patients with extrathyroidal extension.

The ‘CASTLE’ tumour: An extremely rare presentation of a thyroid malignancy. A case report

“…Imaging modalities such as ultrasonography of the neck, CECT head and neck, and magnetic resonance imaging may guide the diagnosis of CASTLE but are usually nonspecific [10]. In a non-enhanced computed tomography of the neck, CASTLE often displays a soft tissue density with an ill-defined border without calcification [6,9].…”

“…Radiotherapy can be used in CASTLE because it has been reported to be radiosensitive [1,2]. Surgery combined with adjuvant radiotherapy has been shown to improve the survival of CASTLE patients [10]. A beneficial effect was seen in cases without lymph node metastasis and tumour extension [12].…”

“…The locoregional recurrence was higher in patients who did not receive radiotherapy [12]. Another modality available for CASTLE treatment is chemotherapy; however, studies have failed to show improved patient survival [2,10].…”

Carcinoma Showing Thymus-Like Differentiation (CASTLE)

“…• Incidence CASTLE is a very rare tumor that accounts for 0.08-0.15% of all primary thyroid malignancies. Nearly 300 cases have been reported to date in the literature, most of them occurring in Asia (Ito et al 2007;Gao et al 2018).…”

“…CASTLE is a locally aggressive tumor with potential to give rise to regional lymph node metastases in half of the cases and distant metastases to distant sites such as lung, liver, and bones. The absence of lymph node metastases and tumor extension to adjacent organs has been reported to be associated to a favorable prognosis (Ito et al 2007;Gao et al 2018).…”