Hyoid Bone and Thyroid Cartilage Metastases from Sigmoid Colon Adenocarcinoma: A Case Report

Abstract

Background: Secondary tumours of the hyoid bone and thyroid cartilage are extremely rare. In this paper, we present a case of the hyoid bone and thyroid cartilage metastases in a patient treated for sigmoid colon adenocarcinoma.

Case report: Four years after sigmoid colon adenocarcinoma was diagnosed and treated with surgery and chemotherapy, the patient developed bone metastases in the left sacroiliac joint and right proximal humerus. Although the patient did not complain of any related symptoms, in a bone scintigraphy the accumulation of Technetium-99m was incidentally detected in the two sites of the anterior neck. On ultrasound examination there were two hyperechoic and heterogeneous masses with calcifications placed in front of the hyoid bone and thyroid cartilage. Computerized tomography demonstrated massive hyoid bone and thyroid cartilage destruction.

Conclusion: In patients with progressive sigmoid colon adenocarcinoma, destruction of the hyoid bone and thyroid cartilage could be suspected for metastases.

Keywords: Hyoid bone; adenocarcinoma metastases; computerized tomography bone scintigraphy.; thyroid cartilage.

Figure 1. Bone scintigraphy shows accumulation of Tc-99m at the two sites of the anterior neck (arrows). Note also the accumulation of Tc-99m in the left iliac bone, sacrum and the right proximal humerus.

Figure 2. Contrast-enhanced CT scans of the neck: (a) Enlargement and osteolyses of the hyoid bone (arrows) presented in a soft tissue and bone window (A-anterior, R-right); (b) Tumour mass in the thyroid cartilage with reactive sclerosis (arrows) presented in a soft tissue and bone window (A-anterior, R-right); (c) 3D reconstruction image of thyroid cartilage (arrow) and hyoid bone (asterisk) defects (A-anterior, H-head, P-posterior, F-foot).