Midline Congenital Upper Lip Sinus: A Rare Case

Abstract

To present a rare case of a midline congenital upper lip sinus and its management. Background: A lip sinus is a rare condition, where a failure of the complete union during early stages of development leads to its formation. The prevalence of lower lip sinus is estimated to be about 0.00001% of the white population and that of upper lip sinus is even rarer. A congenital lip sinus maybe associated with syndromes such as; Von der Woude syndrome, or maybe present in isolation. A 25-year-old male presented to our clinic with intermittent swelling in the upper lip region. Clinical examination revealed a congenital midline lip sinus in the upper lip region, which had no intra-oral communication, and was managed by surgical excision. Till date, there has been a hand full of case reports of upper lip sinuses and fistulae, out of which only few are reported in India. We herein report a case of congenital upper lip sinus presenting as an intermittent swelling of the upper lip with its successful surgical management.

Introduction

Lip pit is a congenital disorder, often hereditary, and may occur alone or in association with cleft lip and/cleft palate in Van der Woude syndrome [1]. They are divided into three types based on their location as; commissural pits (which are small pits near the labial commissure of the mouth) [2], a pit in the upper lip [3] (in which case it may be called a midline sinus of the upper lip) [4], and pits in the lower lip (in which case it may be called a congenital sinus of the lower lip) [4].

Congenital upper lip pit is a rare malformation with its prevalence estimated to be less than the lower lip (0.00001% of white population) [5, 6]. It may be associated with other midline deformities, including double frenum, sinus of the frenum, nasal dermoid cyst and hypertelorism; but tend to be non-syndromic epigenetic malformation [7].

Till date, only few case of upper lip pit has been reported, however less than five similar cases have been described in India. We herein report a case of congenital upper lip pit, which was accurately diagnosed and managed satisfactorily, along with a brief review of literature in this condition.

Case Description

A 26 year old male presented to the clinic with a complaint of intermittent swelling in the upper lip, with no history of trauma/infection in the area. He appeared well with no significant medical/family history. On examination, it revealed that a small pinpoint opening of approximately 1 mm with intermittent swelling in the midline of the upper lip, which was approximately 1 mm below the alar base (Fig. 1). Intra oral examination was normal. A Sinugram was done, which revealed that the opening ended blindly. There was no other associated congenital anomaly. Based on our clinical examination and investigations a diagnosis of a midline congenital sinus of upper lip was made.

Fig. 1.

Photograph shows a midline sinus on the patient’s upper lip

An excision of the congenital sinus tract was scheduled and the surgery was performed under local anesthesia. Intra-operatively, a probe was inserted into the opening, confirming that it did not communicate with the intraoral cavity (Fig. 2). Dissection of the sinus was commenced via an extraoral approach using a vertical wedge incision (Fig. 3). The entire sinus tract was excised in toto (Fig. 4), and the wound was closed in layers. Post operatively the wound healed well, with no recurrence of the lip sinus after 18 months.

Fig. 2.

Photograph shows absence of intra oral communication on probing of sinus tract. a Extraoral view and b intraoral view

Fig. 3.

Photograph shows sinus excised through a vermilion incision

Fig. 4.

Photograph shows sinus tract excised in toto

Histopathological examination of the excised tissue showed a sinus tract, containing keratinous debris lined with keratinizing stratified squamous epithelium associated with sebaceous glands. There was evidence of surrounding chronic inflammation.

Discussion

Congenital lip pits, also called as “congenital sinus of the lower lip”, “lip sinus”, and “midline sinus of the upper lip” [8]; are cutaneous conditions, believed to arise from embryological remnants following the union process [9–11]. But, the exact formation of the upper lip sinus are incompletely understood [7]. Three main proposals have been suggested including invagination theory, merging theory, and fusion theory. The invagination theory proposed that the upper lip sinuses are formed by failure of ectodermal invagination of the nasal placodes during the frontonasal process [12–14]. The merging theory proposes that the sinus is due to aberrations in the normal mesodermal merging process [15, 16]. And, the fusion theory proposes a failure of complete fusion between frontonasal and maxillary processes [17–19]. Out of these theories, the invagination theory receives the most attention, but still the etiology remains controversial [2].

Lip pits usually go undiagnosed/undetected as they are asymptomatic but if infection occurs, and/recurrent discharge is seen; a simple excision via intraoral/extraoral approach is made to treat it [7].

As the upper lip sinuses are rare, so much of the knowledge is based on details of individual case reports [20]. Aoki et al. [21] in 2011 developed a classification for upper lip sinuses, by categorizing them into three main types; Type I: midline sinus without accompanying anomalies; Type II: midline sinus with accompanying anomalies; and Type III: lateral sinus with/without accompanying anomalies.

A total of less than forty cases have been reported of the isolated upper lip pits without associated anomalies (Table 1). Out of all the cases reported previously, it was seen that majority of the patients were Asians and were females [3, 8, 20, 21, 24–29, 31, 32, 34, 37, 39, 40, 42, 43]. Based on the above statement, it may demonstrate that a female predilection along with a racial (Asian) predilection may be seen in this rare condition. However, no conclusive analysis could be made as the number is too small. It is interesting to know that approximately five cases have been reported so far in the Indian literature, which were diagnosed of having “congenital sinus of midline and lateral upper lip” [3, 8, 24, 25, 43].

Table 1.

Published reports of upper lip sinuses and fistulas without congenital anomalies

References	Country	Signs
Parcelier et al. [14]	–	–
Menendez [22]	Guatemala	Recurrent swelling, pus discharge
Holbrook [23]	United Kingdom	Asymptomatic
Mackenzie [17]	United Kingdom	Continuous clear discharge
Parisier et al. [16]	–	–
Kriens et al. [19]	Germany	–
Miller et al. [12]	–	–
Urade et al. [24]	Japan	–
Raibagkar et al. [25]	India	–
Katou et al. [26]	Japan	Asymptomatic
Sakamoto et al. [27]	Japan	–
Mizuki et al. [28]	Japan	Mucoid discharge
Rifaat et al. [9]	United Sates	–
Asahina et al. [29]	Japan	Intermittent swelling, mucoid discharge
Illing et al. [30]	United Kingdom	Asymptomatic
Al-Qattan [14]	Saudi Arabia	Intermittent swelling
Nagasao et al. [31]	Japan	Recurrent swelling and purulent discharge
Sumitomo et al. [32]	Japan	–
Sancho et al. [33]	Spain	Intermittent swelling, clear discharge
Lee et al. [34]	–	–
Charrier et al. [35]	France	Intermittent swelling, clear discharge
Sen et al. [36]	Turkey	Recurrent swelling, discharge, pain, erythema
Nakano et al. [37]	Japan	Intermittent swelling and pus discharge
Salati et al. [38]	Saudi Arabia	Intermittent swelling and discharge
Bhatnagar et al. [39]	India	Recurrent swelling and serous discharge
Aoki et al. [21]	Japan	Intermittent swelling, white discharge, erythema
Anicete et al. [40]	Singapore	Whitish discharge
Fok et al. [20]	Singapore	Recurrent swelling, pus discharge, erythema
James et al. [8]	India	Asymptomatic
Bakshi et al. [3]	India	Recurrent swelling and pus discharge
Rohart et al. [41]	France	Recurrent swelling
Hili et al. [7]	United Kingdom	Asymptomatic
Xu et al. [42]	China	–
Alam et al. [43]	India	Whitish discharge
Present case	India	Intermittent swelling

However, in the present case report, a North Indian male was reported of congenital midline upper lip sinus. The patient was not having any associated anomaly, so was classified as Type I upper lip sinus according to Aoki et al. [21]. His family history did not reveal any familial trend, suggesting that the condition was inherent in nature.

The management of this rare condition becomes challenging, as the clinicians easily overlook the condition because of lack of knowledge due its rarity. To overrule such problems, a thorough history along with thorough examination should be performed before immediately concluding/jumping to diagnosis.

It has been reported that the patient may report some specific signs, such as; swelling, intermittent/recurrent in the region; discharge, white/clear/mucoid/pus maybe seen; erythema and/pain in the area (Table 1). It may also be asymptomatic at times, so it is the duty of the clinician to diagnose it and make the patient aware of the condition, to prevent future complications.

Conclusion

The authors through this case report, reported a case of isolated congenital midline upper lip sinus in a north Indian male. The condition is an extremely rare developmental defect, which should be carefully diagnosed and managed. It is also postulated that the familial trend is seen in patients having defective genes and maybe associated with cleft lip and/or cleft palate.

Lip pits also play an important role in identification of a person through lip prints in forensic medicine/dentistry.

Compliance with Ethical Standards

Conflict of interest

The authors declare that they have no conflict of interest.