J Korean Thyroid Assoc.  2014 May;7(1):88-91.

Carcinoma Showing Thymus-like Differentiation (CASTLE) with Non-Recurrent Laryngeal Nerve: A Case Report

• Choi HG
• Kim CS
• Min SK
• Park B

Abstract

Carcinoma showing thymus-like element (CASTLE) is a very rare malignant neoplasm in the lower portion of the thyroid gland or soft tissue of the neck. Recurrent laryngeal nerve (RLN) is the most frequent site of CASTLE. Non-RLN is also a rare anomaly. Both CASTLE and non-RLN are risk factors for vocal cord paralysis. In this report, the authors describe a 73-year-old patients diagnosed with CASTLE and non-RLN. During total thyroidectomy, one RLN was sacrificed inevitably because of tumor invasion, while the other non-RLN was successfully saved, which was expected based on preoperative computed tomography (CT). If the diagnosis is uncertain, CT should be checked to prevent unexpected risks.

Keyword

Carcinoma; Carcinoma showing thymus-like element (CASTLE); Thyroid; Thymus; Laryngeal nerve

MeSH Terms

Aged
Diagnosis
Humans
Laryngeal Nerves*
Neck
Recurrent Laryngeal Nerve
Risk Factors
Thymus Gland
Thyroid Gland
Thyroidectomy
Vocal Cord Paralysis

Figure

• 

  Fig. 1. Preoperative sonography shows 2.2 cm sized hyperechoic mass.

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  Fig. 2. Preoperative axial view of neck CT shows a 2.2 cm low-density mass in lower portion of left thyroid gland. (A) The white arrow indicates the tumor. Preoperative coronal view of neck CT shows a 2.2 cm sized low-density mass in lower portion of left thyroid gland around the trachea-esophageal grove. (B) The white arrow indicates the tumor. The aberrant right subclavian artery runs against the vertebral column behind the esophagus. (C) The white arrow indicates the aberrant right subclavian artery.

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  Fig. 3. The tumor is divided into variably-sized and irregularly-shaped lobules or bands by fibrous septa. (A) The septa are infiltrated by lymphocytes and plasma cells (H&E stain, ×40). (B) The tumor cells have large vesicular nuclei and prominent nucleoli (H&E stain, ×400). (C) Immunohistochemistry of tumor cells are positive for CD5 (×200). (D) Immunohistochemistry of tumor cells are positive for CD117 (×200). (E) Immunohistochemistry of tumor cells are negative for TTF-1 (×200).

Reference

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