ARTICLE
Auteur(s) : Koji Adachi,
Yuichi Yoshida, Osamu Yamamoto
Division of Dermatology, Department of Sensory
and Motor Organs, Faculty of Medicine, Tottori
University, 36-1 Nishi-cho, Yonago-shi, Tottori 683-8503, Japan
We report an extremely rare case of symmetrical congenital
dermoid fistulae of the anterior chest region.
Case report
An 11-month-old Japanese girl was referred to our department for
evaluation of two small nodules located symmetrically on her
bilateral sternoclavicular joint parts. They had been enlarging
gradually since birth. On physical examination, the right nodule
was light red in color, 20 mm in diameter and palpable as a
subcutaneous funicular nodule with a brown fossa at the center. The
left nodule was yellowish-white in color, 5 mm in diameter and
palpable as a subcutaneous nodule (figure 1A). Magnetic
resonance imaging (MRI) revealed two well-circumscribed masses
located symmetrically in the subcutaneous tissue of the
sternoclavicular joint parts (figure 1B). Both lesions
showed low signal intensities on T1-weighted images and high signal
intensities on T2-weighted images. Bronchogenic cysts were
suspected on the basis of MRI findings. Both nodules were excised
under general anesthesia. They were located in the dermis and
subcutaneous tissue but had no relation to the underlying
mediastina. Histopathologically, the lesion had formed a fistula
structure (figure
1C). The fistulae were lined by keratinizing squamous
epithelium bearing hair follicles and sebaceous glands, and they
contained keratinous materials (figure 1D). Foreign body
granulomatous reaction was also observed in the surrounding dermis.
A diagnosis of symmetrical congenital dermoid fistulae was
made on the basis of these findings.
Discussion
Congenital dermoid fistula of the chest region is a rare skin
fistula [1, 2]. Matsunaga et al. reported 18 cases (male 6, female
12) of congenital dermoid fistula of the anterior chest region
(left 17, right 1) in the Japanese literature [3], and most of
their cases had developed on the sternoclavicular joint parts as in
our case. Although congenital dermoid fistula of the chest region
seems to be female-dominant and arises on the left side of the
sternoclavicular joint part, the reason is unknown. However, they
were all solitary lesions, and there has been no report of
symmetrical congenital dermoid fistulae of the chest region.
Histopathologically, the fistula was lined by a keratinizing
squamous epithelium with hair follicles and sebaceous glands, and
it ended blindly in the subcutaneous tissue. The differential
diagnosis of congenital dermoid fistula includes dermoid cyst and
sinus tract. Subcutaneous dermoid cysts occur most commonly on the
orbital area, but do not usually connect to the overlying
epithelium. Congenital dermal sinus tracts most commonly involve
the midline and may communicate with the central nervous system.
Congenital cutaneous fistula, such as median nasal dermal fistula,
sinus of the upper lip, and sacral dermal sinus, are known to occur
near the median region.
There has been only one case report of a congenital skin fistula
located on the midline of the anterior chest with a sternal cleft
[4]. Divided skin and sternum on the midline of the anterior chest
generally fuse at an early stage of embryonic development. Sternal
cleft is caused by malformations due to partial or total failure of
sternal fusion [5]. Therefore, Miyamoto et al. speculated that the
aetiology of the fistula on the midline of the chest is related to
a developmental defect in the skin during development of the
sternum. There is a possibility that our case also developed
following the same pathogenetic process. However, since details of
embryonic development of the sternoclavicular joint region are not
known, the origin of the symmetrical dermoid fistulae in our case
is still unclear.
Acknowledgements
Conflict of interest: none. Financial support: none.
References
1 Muto J, Mori N, Konohana I, Sato H.
Congenital dermoid fistula of the anterior chest region. Clin Exp
Dermatol 2004; 29: 96-7.
2 Numajiri T, Nishino K, Uenaka M, Sowa Y.
Congenital dermoid fistula of the Anterior chest region. Acta Derm
Venereol 2008; 88: 538-40.
3 Matsunaga W, Ishihara T, Yasuno K. Congenital
dermoid fistula of the anterior chest region. Nishinihonl J
Dermatol 1994; 56: 34-9; (in Japanese).
4 Miyamoto T, Hosoda Y, Fujimoto Y,
Fujishima M, Sasaoka R, Mihara M. Congenital skin
fistula with sternal cleft. Br J Dermatol 1995; 132: 492-4.
5 Heron D, Lyonnet S, Laurence I, Munnich A,
Padovani JP. Sternal Cleft: Case Report and Review of a Series
of Nine Patients. Am J Med Genet 1995; 59: 154-6.
|
Printable version
Version PDF