Cervical chondrocutaneous branchial remnants (CCBRs) are rare congenital anomalies of the neck that arise during early embryogenesis. They typically present at birth as small anterior neck skin tags or nodules with a central cartilaginous core. Historically, CCBRs have been described under various names— including branchial cartilages, cervical auricles, cervical accessory tragi, choristomas, and congenital cartilaginous rests of the neck—reflecting ongoing uncertainty about their embryologic origin and proper classification [1]. This lack of standardized terminology has contributed to diagnostic confusion.

The term CCBRs was first introduced by Atlan et al. in 1997 [2], who proposed a second branchial arch origin based on anatomical and histopathological findings. Their description highlighted several characteristic features, including male predominance, a left-sided laterality preference, the presence of elastic cartilage cores, and a high rate (76.5%) of associated congenital anomalies. Because of its rarity, most published literature consists of isolated case reports or small case series. The two largest earlier series—by Atlan et al. (1997) and Begovic et al. (2014)—each included only 17 patients and focused primarily on lesion laterality, histology, and associated congenital anomalies [2,3]. More recently, Ishigaki et al. [4] reported 29 cases and proposed classifying lesions based on their relationship to the sternocleidomastoid muscle (SCM), marking a step toward more systematic categorization.

Histopathological evaluation has been reported in multiple studies [1-7]. Cartilage composition varied substantially across these reports. Atlan et al. [2] identified exclusively elastic cartilage in all examined cases, whereas Cheon et al. [5] reported hyaline cartilage. Begovic et al. [3] found hyaline cartilage in eight cases (53%) and elastic cartilage in seven cases (47%), and Ishigaki et al. [4] demonstrated elastic cartilage in all assessed specimens. In a comprehensive literature review by Woo and Kim [1], 48.75% of CCBRs contained elastic cartilage, while 15% contained hyaline cartilage. These inconsistent histological findings highlight persistent uncertainty regarding the embryologic origin of CCBRs.

Despite numerous studies, no standardized classification system for CCBRs has been established, and diagnostic terminology remains inconsistent. This lack of consensus has hindered both comparative research and clinical management. Building on our previous work developing a classification system for accessory auricles—which share embryologic and anatomical features with CCBRs [8]—we identified the need for a similarly structured approach to categorizing these neck lesions.

Our institution has managed 55 CCBRs in 53 patients, representing the largest cohort reported to date. The purpose of this study is to propose a comprehensive classification system for CCBRs based on anatomical location, protrusion pattern, and morphological shape. Establishing a reproducible framework for diagnosis and reporting may enhance standardization of terminology and support more consistent management of these rare congenital lesions.

We retrospectively reviewed 55 CCBRs in 53 patients diagnosed between January 2014 and March 2023. Informed consent was obtained from all patients or their legal guardians, and assent was obtained from minors when appropriate. The inclusion criteria consisted of all patients diagnosed with CCBRs, regardless of whether surgical excision was performed. Other congenital branchial anomalies, such as branchial cysts, were excluded. Accessory skin appendages located elsewhere on the body such as on the abdomen were also excluded. Collected data included sex, age at surgery, associated anomalies, histopathological findings, lesion location and shape, and operative details. CCBRs were classified according to anatomical location, protrusion pattern, and morphological shape.

A total of 55 CCBRs in 53 patients—28 males and 25 females— were included in this study. Patient characteristics are summarized in Tables 1 and 2. Of the patients who presented between 2014 and 2023, 42 underwent surgical excision. Most procedures were performed on an outpatient basis under local anesthesia with chloral hydrate syrup. Only two patients underwent surgery under local anesthesia in an inpatient setting: one had an associated anomaly (tongue papilloma), and the other was an adult who did not meet the criteria for outpatient management under hospital policy. The mean age at the time of surgery was 43 months. Most patients underwent excision before 5 years of age, although four patients had surgery at an older age. Two of these were diagnosed and treated in adulthood (≥18 years).

Only four patients had associated anomalies. Two had accessory auricles, one had tongue papilloma, and one had polydactyly. The mean age at diagnosis among patients with associated anomalies was 22.7 months. Because these patients were diagnosed at an older age, routine screening for additional anomalies using imaging such as computed tomography or ultrasound was not performed.

Most CCBRs contained a central cartilaginous core. In some cases, the cartilage was adherent to the platysma fascia (Figs. 3-5), while in others it was attached to the subcutaneous tissue. A notable proportion of lesions demonstrated cartilaginous roots oriented toward the sternum. None of the cartilaginous roots showed connections to deeper neck structures such as vessels or nerves. No serious postoperative complications occurred. All CCBRs were completely excised, and no recurrences were observed.

A total of 10 CCBRs were submitted for histopathological evaluation. All specimens demonstrated elastic cartilage (Fig. 6).

Table 3 presents the classification of CCBRs according to anatomical location. All lesions were confined within predefined cervical boundaries: they did not extend above the upper border of the tracheal cartilage, below the sternoclavicular junction, or lateral to the posterior border of the SCM. No CCBR crossed these limits. A total of eight CCBRs were located in the A central region (seven on the right and one on the left), 26 in the medial region (13 right, 13 left), and 21 in the lateral region (8 right, 13 left). Overall, 28 CCBRs were on the right side and 27 on the left side. Most lesions were located on the lower half of the neck.

Table 4 presents the classification of CCBRs according to protrusion pattern and morphological shape. Among the 55 CCBRs included in this study, the most common morphology was the sessile-ovoid type, observed in 12 lesions (21.8%), followed by the sessile-nodular type in 11 lesions (20%). The pedunculated-ovoid type accounted for eight lesions (14.5%), and the sessile-spherical type for seven lesions (12.7%). Pedunculated-spherical lesions totaled six (10.9%), and pedunculated-lobular lesions five (9%). The sessile-lobular type was seen in three lesions (5.4%), as was the pedunculated-nodular type (5.4%). The distribution of CCBR locations and shapes is illustrated in Fig. 7, and their relationship by category is summarized in Table 5. Sessile-nodular lesions were present across all location categories. Sessile-ovoid lesions were also widely distributed but were absent in the left central region. Sessile-lobular lesions occurred exclusively on the left side (left medial and left lateral). Sessile-spherical lesions were found only in the medial and lateral regions on each side. In contrast to the relatively patterned distribution of sessile types, pedunculated types showed no consistent regional pattern. Among the 53 patients, two had bilateral CCBRs, and in both cases the lesions were located on opposite sides of the neck.

This study reports 55 CCBRs in 53 patients, representing the largest single-institution series published to date. We propose a systematic classification based on anatomical location and mor-phological characteristics. Although previous studies have explored demographic features and embryologic considerations, no formal classification scheme for CCBRs has yet been established.

Previous reports have suggested demographic patterns in CCBR presentation, including male predominance and a leftsided laterality preference [4]. However, our series demonstrated no significant differences in sex distribution or laterality, with relatively balanced representation across both variables. This discrepancy may be related to differences in sample size compared to earlier, smaller case series. As the largest single-institution series to date, our findings may contribute additional data toward understanding demographic patterns in CCBR presentation. Our series also documented a markedly low incidence of central CCBRs, a finding that is consistent with current embryologic concepts. According to prevailing developmental models, the auricular hillocks originate in a relatively ventral (anterior) position and subsequently migrate laterally along the SCM to reach their definitive location [2]. Within this framework, midline CCBRs may represent an early arrest of this migratory process, whereas more lateral lesions could reflect interruption at later developmental stages. The relative rarity of midline lesions may suggest that very early developmental arrest is less common. Similarly, the predominance of lateral lesions in our series may be consistent with disruption occurring during intermediate to later phases of hillock migration.

The embryologic development of the branchial arch system begins in the early fourth gestational week, with all six arches completing their morphological differentiation by the end of the seventh week [2]. Although the precise origin of CCBRs is not fully established, current evidence suggests derivation from the first or second branchial arch based on characteristic histological features [2]. Most reported CCBRs contain elastic cartilage, although some series have described hyaline cartilage variants [5]. The presence of hyaline cartilage argues against an auricular origin and instead supports a cervical source arising from lower branchial arch derivatives [2,4].

Atlan et al. [2] proposed that the six auricular hillocks arising from the first and second branchial arches migrate along the developing SCM to reach their final lateral facial position, with CCBRs representing tissue “left behind” during this migratory process. If the lesion had demonstrated hyaline cartilage, a second or third branchial arch origin would be suspected [2]. Our histological analysis is consistent with Atlan’s embryologic hy-pothesis. All 10 specimens examined by our pathology department demonstrated elastic cartilage. Surgically, all cartilaginous cores terminated at or anterior to the SCM, with none extending posterior to the SCM. This pattern may be consistent with the migratory theory, given that auricular hillocks are not thought to migrate behind the SCM [2]. The predominance of elastic cartilage in our series, together with the consistent anterior- to-SCM anatomical relationship, may support the embryologic framework proposed by Atlan et al. and further discussed by Ishigaki et al. [2,4].

Our findings partly align with earlier studies but also show some differences that warrant consideration. Atlan et al. [2] and Begovic et al. [3] reported relatively high rates of associated systemic anomalies and recommended comprehensive cardiac and abdominal screening in affected patients. In contrast, Ishigaki et al. [4] documented a substantially lower prevalence of associated malformations, suggesting that earlier reports may have overestimated the degree of systemic involvement. Our series is more consistent with the more conservative interpretation of Ishigaki et al., as only four patients presented with associated anomalies—a tongue papilloma, polydactyly, and two accessory auricles. This low prevalence suggests that CCBRs may often present as isolated anomalies rather than markers of syndromic disease. The lower incidence of associated anomalies in our series may reflect differences in healthcare accessibility. In South Korea, ready access to medical facilities encourages families to seek care for even minor lesions, potentially resulting in earlier detection of isolated CCBRs. This contrasts with healthcare settings in which patients may present later or with more complex manifestations. Accordingly, routine extensive screening may not be required in all asymptomatic patients with isolated CCBRs, although a careful physical examination remains essential.

We classified CCBRs according to their anatomical location into three zones—central, medial, and lateral—based on their relationship to the tracheal cartilage and SCM. Shape was categorized by protrusion pattern (pedunculated or sessile) and body configuration (spherical, ovoid, lobed, or nodular), yielding eight morphological subtypes. This method parallels a previously established classification system for accessory auricles [5], which share similar embryologic characteristics with CCBRs.

In our series, the medial location was most common (47%), followed by the lateral zone (38%). Sessile lesions (60%) were more frequent than pedunculated lesions (40%), and the ovoid configuration (36%) predominated. Bilateral lesions have been rarely reported in the literature [9-13], and only 2 of 53 patients (3.8%) in our cohort demonstrated bilateral involvement. Ishigaki et al. [4] reported that most lesions were located in the lower anterior neck, primarily anterior to the SCM. Our anatomical classification may further characterize lesion distribution by systematically mapping lesions in relation to both the SCM and tracheal cartilage. This dual-landmark approach may provide a more structured anatomical framework that could be helpful for preoperative planning and intraoperative orientation. By establishing anatomical zones based on readily identifiable surgical landmarks, our classification system may offer a useful reference for comparative research and potentially assist in clinical decision-making.

In conclusion, this study presents the largest single-institution cohort of CCBRs reported to date. Unlike previous reports, our series demonstrated no significant differences in sex distribution or laterality. Histopathological examination revealed elastic cartilage in all analyzed specimens, supporting the auricular hillock migration theory of CCBR embryogenesis proposed by Atlan et al. [2]. The incidence of associated congenital anomalies was notably low (7.5%), suggesting that routine systemic screening may not be necessary in all patients. We propose a systematic classification framework that categorizes CCBRs by anatomical location (central, medial, and lateral zones) and morphological characteristics (protrusion pattern and body shape). However, several limitations of this study should be acknowledged. The retrospective design introduces potential selection and information bias, and the single-institution setting may limit the generalizability of the findings. In addition, histopathological evaluation was performed in only a subset of cases, limiting the strength of conclusions regarding embryologic origin. Interobserver agreement was not formally quantified, which may affect the reproducibility of the proposed classification system. Despite these limitations, this standardized approach facilitates consistent terminology across institutions and provides a foundation for future comparative research and treatment optimization. Multicenter validation of this classification system is encouraged.