Cyst-like change in the thyroid cartilage: A developmental variant in children

Abstract

Neck sonography is frequently encountered on ultrasound lists in the paediatric patient population. Anecdotally, one of the most frequent clinical indications is the investigation of a neck lump. While performing an ultrasound of the neck, structures other than those routinely assessed, such as the thyroid cartilage and mandibular cortex also come into view. Occasionally, pathology in these structures is also encountered, albeit less frequently. The purpose of this case report and review is to illustrate the ultrasound, computed tomography and magnetic resonance imaging appearances of cyst-like changes in the thyroid cartilage that are encountered in children, particularly in early adolescence. KeywordsThyroid cartilage, cysts, ultrasound, developmental variant, paediatric Case reportA 16-year-old male patient presented to the radiology department for an ultrasound of his neck with a history of intermittent swelling in the left submandibular area. On ultrasound, the palpable swelling corresponded to a prominent submandibular lymph node that was of normal architecture. The lymph node was not significant by imaging size criteria and demonstrated normal vascularity on colour Doppler studies. A few smaller lymph nodes were also noted bilaterally. Normal appearances of the thyroid gland and of the parotid and submandibular glands bilaterally were demonstrated. Incidentally, two well-defined, homogenously hypoechoic, avascular structures were identified in the thyroid cartilage bilaterally (Figure 1(a) and (b)). At the time of the scan, the impression of benign, cystic cartilaginous lesions was made. However, a magnetic resonance imaging (MRI) of the neck was advised for further assessment and to exclude any sinister pathology.Corresponding to the two focal areas of abnormality identified on ultrasound, two small well-defined areas of signal abnormality that were of high signal on the fatsuppressed sequence (Figure 2(a)) and of intermediate signal on the T1-weighted sequence (Figure 2(b)) were seen. Apart from a few lymph nodes that were accepted to be within normal limits, no other abnormality was present.On the follow-up ultrasound scan acquired two months later, the hypoechoic thyroid cartilage lesions appeared stable in size and sonographic characteristics. No new focal cartilaginous lesions were identified. DiscussionFocal lesions of the thyroid cartilage are rare. Cases of chondromas, chondrosarcomas, degenerative cysts of the thyroid cartilage, possible post-traumatic cysts and another that may have been associated with postradiotherapy cystic degeneration have been described in

Thyroid Cartilage Cysts, A Rare Entity Causing Dysphonia

“…Together with our own five cases, an overview of 17 cases consisting of patients aged from 13 to 83 years is summarized in Table I. [1][2][3][4][5][6][7][8] In 10 cases, these cysts were detected due to vocal complaints, the other seven were published as radiological findings, without information concerning the voice. In surgically treated cases, histopathology all showed the same: degenerative cyst of the thyroid cartilage, without signs of malignancy (Burgess and Yim, n = 1, 1 Calderon et al, n = 2, 2 Garrel et al, n = 1, 6 Galline et al, n = 1 7 ), which is in line with our five cases.…”

“…We reviewed the English‐language literature and to our knowledge present the largest series of cases reported. Together with our own five cases, an overview of 17 cases consisting of patients aged from 13 to 83 years is summarized in Table …”

A developmental variant of the thyroid cartilage

“…The cyst-like formations of the thyroid cartilage are uncommon and are incidental findings on imaging, mainly seen in the adolescent age group (2) .…”

“…They are considered developmental variants and their appearances are correlated with the degree of mineralization and calcification occurring during adolescence (2) .…”

“…The ossification process begins in the inferior portion of the posterior third of the lamina and inferior horn (2) . The anterior half of the cartilage usually ossifies at the late stage with a tendency to partial calcification at this level in the female population (1,2) . The unossified areas within the thyroid laminae often persist as radiolucent "windows" till an advanced age (1,2) .…”