Volume 2, Issue 4 , Pages 225-227, December 2007
Case report of a unilateral cervical chondrocutaneous branchial remnant
Article Outline
Summary
Cervical chondrocutaneous branchial remnants are rare and unusual choristomas (dysgenetic tumor, originating from dislocated tissue). To get proper understanding of the etiology and consequently histology, knowledge of early embryologic processes from cartilage structures in the head and neck region is mandatory. A case of a 3 days old girl with a unilateral, cervical chondrocutaneous branchial remnant tumor in the lower half of the neck is presented.
Keywords: Cervical chondrocutaneous branchial remnant, Choristoma, Accessory tragus, Congenital tumor
1. Introduction
Pre-auricular located accessory tags are well known entities. However, choristomas (dysgenetic tumor, originating from dislocated tissue) located elsewhere are infrequently described [1]. In addition chondrocutaneous branchial remnants (CCBRs), rare and unusual choristomas located in the lateral side of the neck, are very rarely reported in literature [2]. The only relatively large series described is by Atlan et al. [3]. In their report more than half of the included population had one or more supplementary congenital disorders, most of which were urogenital in origin.
To get proper understanding of the etiology of CCBR, knowledge of early embryologic processes from cartilage structures in the head and neck region is essential.
We report a case of a 3 days old girl with a unilateral, cervical chondrocutaneous branchial remnant tumor in the lower half of the neck.
2. Case report
A 3 days old girl presented after an uneventful pregnancy and birth with a left-sided, smooth exophytic tumor in the lower half of the neck which was already noticed at birth (Fig. 1). The tumor measured about 1.5
cm. No other swellings were present. The lesion had a firm but elastic consistency and was mobile in relation to its underlying structures. The overlying skin was similar to the surrounding neck skin, without any differences in color or elasticity. No signs of an epidermal pit or pore were present. The tumor seemed painless and lacking any signs of inflammation or discharge. General physical pediatric examination revealed a well-developed healthy infant without signs of urogenital abnormalities. Especially, no dysmorphic signs were present like palatoschizis, cheiloschizis, a hypoplastic mandibula or abnormally shaped auricles. There was no family history of congenital abnormalities, mental retardation, chromosomal abnormalties or consanguinity.
Fig. 1.
Unilateral pedunculated tumor in the lower left half of the neck.
During excision of the tumor, which was undertaken at the age of 6 months, the lesion extended into the neck and connected to the fascia at the anterior part of sternocleidomastoid muscle.
Histological examination revealed a completely excised tumor, measuring 20mm×10mm×6mm (Fig. 2). It was surrounded by adipose tissue, hair follicles and exocrine glands. The overlying epidermis was normal and intact. Standard hematoxyline–eosine staining of the tissue showed the presence of central islands of chondrocytes beneath the level of the epidermis. A second staining (Lawson) indicated the composition of the chondrocytes, to be of the elastic cartilage type. At the base the tumor was connected to striated muscular tissue. This was the site where the tumor had been connected to the sternocleidomastoid muscle (Fig. 3). No evidence of glandular, epithelial or cystic tissue was found. No indications for malignancy were found.
Fig. 2.
CCBR after excision; at the lower right side the elastic cartilage cone where the tumor had been connected to the sternocleidomastoid muscle.
Fig. 3.
Chondrocytes islands, of the elastic cartilage type beneath the level of the normal epidermis.
Follow up after 6 months showed no signs of recurrence.
3. Embryology
The auricle (as well as the middle ear structures) derives its embryonic origin from structures in the first and second pharyngeal arches.
In the sixth week, six auricular hillocks appear on the first and second pharyngeal arches. The auricle (pinna) will develop from these structures.
From ventral to dorsal the following auricular structures develop successively out of the hillocks on the first pharyngeal arch: tragus, helix and concha-cymba. And from the second pharyngeal arch in turn develop the antitragus, antihelix and concha.
During the seventh week the auricular hillocks start to enlarge and differentiate. They fuse and form the primordial auricle. The auricle starts to translocate from its initial ventral position on the lower side of the lateral neck to its ultimate lateral cranial destination. During this migration it follows the anterior border of the sternocleidomastoid muscle.
The presence of an abnormal development of one or more auricular hillocks can result in a malformation of the auricula. Ectopic auricular tags can also develop from accessory hillocks [2].
4. Discussion
As already mentioned, in the embryological phase, the branchial arches are initially positioned in a relative ventral position and migrate along the sternocleidomastoid muscle to a more cranial position. Cells that are left behind during this process, can give rise to formation of CCBR [2], [4]. This explains the frequent finding that CCBR are attached to the sternocleidomastoid muscle, as was the case in our patient (Fig. 4).
Fig. 4.
Detail of elastic cartilage type and dermal tissue. The elastic fibers stain black (van Gieson elastic stain, 400×).
At histological examination of the excised CCBR, elastic cartilage was found. This supports the hypothesis that the origin of CCBR has to be sought in embryological remnants of the primordial auricular [2] and not for instance in the primordial laryngeal remnants which largely contain hyaline cartilage.
CCBR have, despite their clear clinical markings, a broad differential diagnose [5]. It includes thymic cysts and thyroglossal duct cysts, branchial cleft, hair follicle nevus, congenital midline hamartoma, fibroepithelial polyp, epidermoid cyst and squamous papilloma. Thymic cysts are lined with stratified squamous epithelium and filled with fluid. Thyroglossal duct cysts are located anteriorly and can sometimes contain thyroid follicles. Branchial cleft cysts are located laterally and are lined by upper respiratory epithelium; they have a shallow epidermal pore and contain seromucinous glands. Congenital midline hamartomas contain a prominent skeletal muscle component and are found on the anterior mandibula. Epidermoid cysts, squamous papillomas and fibroepithelial polyps do not usually present differential diagnostic difficulties.
5. Summary
CCBR's are rare, benign and congenital neck masses. The cartilaginous islands of the elastic type are characteristic of this entity, distinguishing them from other congenital tumors. One ought to be aware of the embryologic derivation in order to be fully acquainted with its relation to the sternocleidomastoid muscle. CCBR's are frequently associated with other congenital disorders such as e.g. urogenital anomalies, which have to be excluded.
References
- Case report of bilateral cervical chondrocutaneous branchial remnants. Int. J. Pediatr. Otorhinolaryngol. 2003;67(1):89–92
- . Development of The Ears. Human Embryology. second ed.. Cincinnati: Churchill-Livingstone; 1997;pp. 385–392
- . Cervical chondrocutaneous branchial remnants. Plastic Reconstr. Surg. 1997;100:32–39
- . Congenital cartilaginous rests of the neck (wattles). Arch. Pediatr. Adolesc. Med. 1994;148(2):211–212
- . An anterior neck mass in a 5-month-old female infant. Arch. Pathol. Lab. Med. 2004;128:1453–1454
PII: S1871-4048(07)00054-8
doi:10.1016/j.pedex.2007.06.006
© 2007 Elsevier Ireland Ltd. All rights reserved.
Volume 2, Issue 4 , Pages 225-227, December 2007
