Dr R.P Panigrahi (ENT SPL) ESIC

MODEL HOSPITAL ROURKELA.

INTRODUCTIONPre-auricular sinus was first described by

Van Heusinger in 1864.[1]Pre-auricular sinus is a benign

congenital malformation of pre-auricular soft tissues.[3] It is also known as Pre-auricular sinuses, Pre-auricular pits, Pre-auricular fistula, pre-auricular cyst.

INCIDENCE• It has an estimated incidence of 0.1% to

0.9% in general population. It is more frequently in Taiwan 1.6% to 2.5%.[4]

• Leung and Robson in Calgary, Canada carried out a prospective study to investigate the incidence of renal anomalies associated with specifically pre-auricular sinus and concluded such anomalies were significantly more common in patients with a pre-auricular sinus.

There continues to be a strong association between pre-auricular pits and renal defects. A lot of syndromes like Branchio-Oto- Renal-Syndrome (BOR) and Branchio-Oto- ureteral-syndrome have been documented where pre-auricular sinus and renal anomalies do coexist. [6]

D/D of Post Auricular abscess and sinuses Infected epidermoid cysts.1st Branchial Cleft anomalies.Inflamed adenopathy.Mastoiditis.Subperiosteal abscess.

CLINICAL FEATURES

In most cases sinuses are clinically silent eventually however appearance of symptoms is related to an infectious process. Erythema, swelling, pain and discharge are familiar sign and symptoms of infections.

The most common pathogen causing infections are Staph-species and less frequently Proteus, streptococcus and peptococcus. In all cases, part of the tract blends with the perichondrium of auricular cartilage.

Case Report

A 48 years old male from nearby region presented to the ENT OPD in Nov 2012 with a draining sinus in the post auricular region of right side (just behind the Rt ear lobule) unhealthy skin around the infected sinus and a hypertrophied pigmented skin lesion below the right ear lobule were present.

Fig:-1 Cannulation of the right post-auricular sinus and methylene blue injection intra operatively.

• This region was soared and tender with pus draining out from the sinus. The patient was unable to move his head properly due to pain in neck.

• A review of his medical history revealed that recurrent infection of this area occurred once in every three-four months since he was a teenager and he remembers that he was caring this disease for last thirty years or more.

The patient had undergone surgery six times before in different hospital of this area and Medical colleges of this region.

He did not have the biopsy reports of his 6 previous surgeries. In between the surgeries when recurrence occurred he was managed conservatively by antibiotics and analgesics by local physician.

A careful clinical examination was performed where right tympanic membrane was normal. The mastoid appeared normal in X-rays. PTA finding was within normal limit. A sinogram was attempted but results were not good. Except routine examination for GA no specific investigations were done.

During the operation methylene blue was injected in to the right post auricular sinus. Operation was done by standard technique (simple sinectomy) under GA. In which an ellipse of skin surrounding the post auricular opening was excised and the tract was dissected out in –toto under microscopic guidance. [2]

Fig-2 Excision of the tract

The specimen was excised en-block including the wedge of tragal cartilage which was partially ossified. and the mass was sent for HP studies.

HISTOPATHOLOGICAL STUDY OF THE SPECIMENHisto-pathological study say it was

consistent with sebaceous hyperplasia with chronic inflammatory granulation tissue lining the tract.

Fig-3 Specimen of the sinus tract with portion of tragal cartilage.

Fig-4 Excision of the tract with tragal cartilage.

Fig-5 Two month post operatively, the patient has a hypertrophic scar at the incision site.

• In all cases of pre auricular sinus a part of the tract blends with the peri-chondrium of auricular cartilage and in this case the tract blended with the tragal cartilage.

• The patient has been asymptomatic for last one and half year and has visited four times to the ENT OPD and had no complain except a hypertrophic scar below the right ear lobule.

DISCUSSION

• The external ear develops from six mesenchymal hillocks (hillocks of His) around the 6th week of gestation.

• Three hillocks from the caudal border of the first branchial arch and three hillock from the cephalic border of the second branchial arch fuses to form the definitive auricle.

• The tragus and the margin of the anterior crux of helix develops from the 1st arch and the rest of [7] auricle is formed from the 2nd arch.

The three predominant theories for the development of preauricular sinuses are [8]

1) possible incomplete fusion of the 1st arch hillock.

2)isolation of the ectodermal folds during the auricle formation.

3)defective closure of the most dorsal part of the first branchial cleft.

Over 50%of cases are unilateral and most often sporadic. [10] It occurs most commonly on right side as in this case. Bilateral cases are more likely to be inherited, when inherited the pattern is of incomplete autosomal dominance with reduced (around 85%)penetrance{8,15}. [3]

Pre auricular sinus and anomalies of the first-branchial cleft can have similar presentation. Pre-auricular sinus usually present with an opening anterior to the ascending limb of helix. Occasionally, they occur along the lateral or the posterior surface of the helicine crux and the superior posterior margin of the helix, the tragus or the lobule. [9]

Type-1 anomalies of the 1st branchial cleft can present as a cyst or sinus within the ear canal or post-auricular area with an opening in the check.

The pre-auricular sinus is lateral to temporalis fascia, the facial nerve and to the parotid fascia in contrast to the tract 1st Branchial cleft which tends to be intimately related to these structures.

Hence these features suggest that the lesion was a pre-auricular sinus instead of type-1 anomoly of branchial cleft . Pre-auricular sinus presenting as post-auricular inflammation or sinuses have rarely been reported

Chang and Wu reported 3 cases presenting as post auricular cyst. Yeo. [5,9] etal reported 2 cases where the pit was located in the post-auricular area among a total of 191 patient.

CONCLUSIONChoi. Et al described the variant-of the

pre-auricular sinus.1-The patients are located in the middle

area of the crux.2-The patients are located in the

superior area of crux.3-The patients are located in cymba

concha.

• The present case however, does not fall into any of the above said categories as the sinus tract had gone down from post-auricular region up to the medial aspect of the tragal cartilage.

• Hence a recurrent post-auricular infected cyst or sinus may, albeit uncommonly, indicate an aberrant pre-auricular sinus and the ENT surgeons should carefully examine possibility also.

-:REFERENCE:- H.K Heusinger, “Hals-Kiemen Finstein von Noch Nicht Beobacheter Form,” Virchows Archiv, Vol.

29, No.3-4,1864, pp.38-380. doi :10.1007/BF01937182.   Lam HC, Soo G, Wormald P. J, Van Hasselt CA. Excision of the Pre-auricular Sinus: a comparison of two

surgical techniques. Laryngoscope. Feb 2001;111(2):317-9.[Medline].[Full Text].   R. Martin-Granizo, M.C. Perez-Herrero and A. sanchez Cuellar, “Methylene Blue Staining and Probing for

Fistula Resection: Application in a Case of Bilateral congenital Preauricular Fistulas, “International journal of Oral and Maxillofacial Surgery, Vol.31, No. 4, 2002, pp.439-441. doi:10.1054/ijom.2001.0062.

  I. Aird, “Ear-pit: Congenital Aural and pre-auricular Fistula, “Edinburgh Medical Journal, Vol. 53, No9,

1964, pp 498-507.   P.H. Change and C. M. Wu, “An insidious Pre-auricular Sinus presenting as an infected Post-auricular

Cyst, “International Journal of Clinical Practice, Vol,59, No, 3, 2005,pp 370-372. doi:10.1111/j.1742-1241.2005.00437.x

  Kumar Chowdary KV, Sateesh Chandra N,karthik Madesh R. preauricular sinus, a noval approach. Indian

J Otolaryngol Head Neck Surg.Jul 2013;234-6.[Mediline].   S.J. Choi, et la., “The Variant Type of Pre-auricular Sinus: Post-auricular Sinus, “Laryngoscope,

Vol.117,No 10, 2007,pp. 1798-1802.doi:10.1097/MLG.0b013e3180caalca   P.J. Emery and N.Y. Samal, “Congenital Pre-auricular Sinus. A Study of 31 cases seen over 10years

period”, International Journal of Pediatric Otorhinolaryngology, Vol.3,No.3,1981,pp.205-212.doi:10.1016/0165-5876,(81)90004-5

  S.W.Yeo, et al., “The Pre-auricular Sinus: Factors contributing to Recurrence after Surgery”, American

Journal of Otolaryngology/Head and neck medicine and Surgery, Vol.27,No.6,2006,pp.396400.doi:10.1016/j.amjoto.2006.03.008

  Y.C.Nofsinger, et al., “ Pre-auricular Cysts and Sinuses,” Laryngoscope,Vol.107,No.7,1997,pp.883-

887.doi:10.1097/00005537-199707000-00009.