Department of Dermatology, School of Medicine, University of California San Diego, La Jolla, California, USA
Author’s e-mail: mitehead@gmail.com

حديبة دارون
فيليب كوهني

Darwin’s Tubercle
Philip R. Cohen

A healthy 47-year-old man presented to the dermatology office of the University of California San Diego, La Jolla, California, USA, 
in 2017 for a complete examination of his skin. On the 
posterior-superior helix of his left ear, an asymptomatic 
firm elastotic triangular prominence of skin-covered 
cartilage was observed, measuring 10 x 10 x 22 mm 
[Figures 1A and B]. In addition, there was a cutaneous pit 
in the left preauricular area [Figure 1C]. A similar yet 
less pronounced helical tubercle was also present on his 
right ear. The patient had no family history of auditory 
or renal impairment.

Comment

Darwin’s tubercle is a benign and unique helical feature 
that often appears as a solitary peculiarity on the 
ear but can also present bilaterally on both ears.1 
While the condition requires no additional evaluation 
or treatment, surgical treatment—consisting of a full- 
thickness excision of the skin and the prominent 
cartilage underneath—may be considered in order to 
address cosmetic concerns. In addition to Darwin’s 
tubercle, other peculiarities of the helix include pointy 

ear, satyr ear and Stahl’s ear deformity.1,2 Although 
Darwin’s tubercle usually occurs alone, it has been 
associated with accessory tragus, congenital absence 
of the helix and weathering nodules.1,2

Isolated preauricular pits are a congenital anomaly 
with an incidence of 5–10 cases per 1,000 newborns.3 
According to recent research, hearing tests or a urin- 
alysis are not recommended for patients with pre-
auricular pits unless the individual has an associated 
syndrome or a family history of auditory or renal 
impairment.3,4 Therefore, the current patient did not 
require any additional evaluation or treatment of his 
preauricular pit. 

Darwin’s tubercles contribute to the individuality 
of human ears and may have applications in the fields 
of personal identification or forensic sciences.1 The 
presence of Darwin’s tubercle has not been associated 
with any significant adverse clinical consequences or 
systemic anomalies, including chondrodermatitis or 
hearing and urinary anomalies. The concurrent pres-
ence of Darwin’s tubercle and a preauricular pit of the 
ipsilateral ear, such as that observed in the present case, 
may represent a coincidental occurrence rather than 
an association between the two conditions. 

interesting medical image 

Sultan Qaboos University Med J, February 2018, Vol. 18, Iss. 1, pp. e112–113, Epub. 4 Apr 18
Submitted 22 Oct 17
Revision Req. 21 Nov 17; Revision Recd. 26 Nov 17
Accepted 30 Nov 17

 
Figure 1: Photographs of the left ear of a 47-year-old man showing (A) a Darwin’s tubercle presenting as (B) a 
prominence of the posterior-superior helix (arrows). In addition, (C) a preauricular pit (asterisk) was observed.

doi: 10.18295/squmj.2018.18.01.021



Philip R. Cohen

Interesting Medical Image | e113

3. Firat Y, Sireci S, Yakinci C, Akarçay M, Karakaş HM, Firat AK, 
et al. Isolated preauricular pits and tags: Is it necessary to 
investigate renal abnormalities and hearing impairment? Eur 
Arch Otorhinolaryngol 2008; 265:1057−60. doi: 10.1007/s004 
05-008-0595-y.

4. Kugelman A, Hadad B, Ben-David J, Podoshin L, Borochowitz Z, 
Bader D. Preauricular tags and pits in the newborn: The role 
of hearing tests. Acta Paediatr 1997; 86:170−2. doi: 10.1111/
j.1651-2227.1997.tb08860.x.

References
1. Loh TY, Cohen PR. Darwin’s tubercle: Review of a unique 

congenital anomaly. Dermatol Ther (Heidelb) 2016; 6:143−9. 
doi: 10.1007/s13555-016-0109-6.

2. Lykoudis EG, Seretis K, Spyropoulou GA. A 6-year experience 
in flat helix correction with a simple procedure. Arch Facial 
Plast Surg 2011; 13:168−72. doi: 10.1001/archfacial.2011.31.

https://doi.org/10.1007/s00405-008-0595-y
https://doi.org/10.1007/s00405-008-0595-y
https://doi.org/10.1111/j.1651-2227.1997.tb08860.x
https://doi.org/10.1111/j.1651-2227.1997.tb08860.x
https://doi.org/10.1007/s13555-016-0109-6
https://doi.org/10.1001/archfacial.2011.31