1. Oral Maxillofac Surg
DOI 10.1007/s10006-010-0257-2
CASE REPORT
Lateral periodontal cyst: report of case and review
of the literature
Márcia de Andrade & Ana Paula Pantosi Silva &
Flávia Maria de Moraes Ramos-Perez & Yara Teresinha Corrêa Silva-Sousa &
Danyel Elias da Cruz Perez
Received: 10 August 2010 / Accepted: 17 November 2010
# Springer-Verlag 2010
Abstract Keywords Differential diagnosis . Lateral periodontal
Background As the lateral periodontal cyst (LPC) is an cyst . Review
unusual odontogenic cyst, most papers are single case
reports or series with a limited number of cases, with
few large series. The aim of this study is to report an Introduction
additional case of LPC, emphasizing the clinical, radio-
graphic, and histopathological features, differential diagnosis, Lateral periodontal cyst (LPC) is an uncommon development
and review of 264 cases reported in the English-language odontogenic cyst, representing about 0.4% of all odontogenic
literature. cysts [1] and 0.7% of all cysts of the jaw bones [2]. This
Case report A 51-year-old male patient presented with a lesion is defined as a radiolucent lesion that grows along the
well-delimited, radiolucent, mandibular lesion, located lateral surface of an erupted vital tooth, in which an
between the roots of the right lower lateral incisor and inflammatory etiology has been excluded, based on clinical
canine and evidenced during routine radiographic examina- and histological features [2, 3].
tion. A surgical excision was performed. Microscopically, The LPCs originate from remnants of odontogenic
there was a cystic cavity lined by simple squamous epithelium [4, 5]. These lesions are more common in adults
epithelium, compatible with LPC. during the fifth to seventh decades of life and demonstrate a
Discussion LPC is an unusual odontogenic cyst and male predilection [5], despite the fact that some studies
presents a marked predilection for occurring in the have not reported a gender preponderance [2, 6–9]. Most
mandible between the roots of canines and premolars. LPCs are located in the mandibular–premolar area, followed
Accurate clinical and imaging exams should be performed by the anterior region of the maxilla [10–13]. Radiographic
for a correct approach and diagnosis. features demonstrate a well-defined, circumscribed, round or
ovoid radiolucent lesion, usually with a sclerotic margin,
preferentially localized between the apex and the cervical
margin of the teeth [3].
M. de Andrade : A. P. P. Silva : Y. T. C. Silva-Sousa :
Botryoid odontogenic cyst (BOC) is considered a variant
D. E. da Cruz Perez
School of Dentistry, University of Ribeirao Preto, of the LPC, presenting as a multicystic lesion. Due to the
Ribeirao Preto, Sao Paulo, Brazil polycystic aspect, radiographically, most of these lesions
are multilocular. In the same way, the gross aspect is similar
F. M. de Moraes Ramos-Perez : D. E. da Cruz Perez
to a cluster of grapes. This lesion may be extensive and has
Federal University of Pernambuco,
Recife, Pernambuco, Brazil a higher risk of recurrence than LPC [14, 15]. In both
lesions, LPC and BOC, the most adequate treatment is a
D. E. da Cruz Perez (*) complete surgical enucleation [5].
Curso de Odontologia, Universidade Federal de Pernambuco,
As LPC is an uncommon lesion, most papers are single
Av. Prof. Moraes Rego, 1235, Cidade Universitária,
CEP: 50670-901, Recife, Pernambuco, Brazil case reports or series with limited number of cases, with
e-mail: perezdec2003@yahoo.com.br few large series (Table 1). Thus, the aim of this study is to

2. Oral Maxillofac Surg
Table 1 Summary of the
epidemiological features of large Authors Number of Mean age Gender Site
LPC series cases (male/female) (mandible/maxilla)
Cohen et al. [7] 37 54 18:19 29:8
Rasmusson et al. [27] 32 55 22:10 28:4
Carter et al. [8] 23 49.4 12:11 19:3a
Jones et al. [1] 28 48.2 16:12 NA
a
The site was not available in one Shear and Speight [2] 24 Range 19–71 12:12 14:10
case
report an additional case of LPC, emphasizing the clinical, tumor were the most likely clinical and radiographic
radiographic, and histopathological features, differential diagnoses. Under local anesthesia, complete surgical excision
diagnosis, and review of 264 cases reported in the of the lesion was performed, without intercurrences.
English-language literature. Macroscopic analysis revealed a unicystic lesion. Histopath-
ologically, the lesion consisted of a cystic cavity lined by simple
nonkeratinizing squamous epithelium, although in some
Case report regions, the cavity was lined by a double layer of cells (Figs. 2
and 3). Clear cells were also observed. Moreover, inflamma-
A 51-year-old male patient was attended to in a private tory cells were not observed in the connective tissue from the
dental clinic due to a radiolucent mandibular lesion, cystic wall. According to clinical, radiographic, and histo-
evidenced during routine radiographic examination. The pathological features, a diagnosis of LPC was established.
patient denied pain or any other symptoms. On intraoral After the treatment and adequate postoperative exams, the
exam, there was a painless, well-circumscribed, slight patient was lost to follow-up.
swelling, sited in the gingival mucosa between the right
lower lateral incisor and canine, which presented a hard
consistency and was covered by normal mucosa. Discussion
Periapical radiography revealed a well-circumscribed,
radiolucent, unilocular lesion, located in the mandible, The LPC is an uncommon odontogenic cystic lesion of the
laterally and between the roots of the right lower lateral jaws, which develops in the alveolar bone along the lateral
incisor and canine, without corticated margins, measuring surface of a vital tooth [3, 5, 7, 16]. Most cases are
about 1.0 cm in diameter. In addition, a slight divergence of discovered on routine radiological examination, since
the roots of the teeth was observed (Fig. 1). Thermal test usually, these lesions are initially asymptomatic, as it was
revealed pulpal vitality of the two teeth adjacent to the observed in our case. However, the lesions can present a
lesion. Additionally, periodontal exam excluded a lesion of gingival swelling during their development and growth [5,
inflammatory origin. LPC and the keratocystic odontogenic 12, 13].
Fig. 1 Well-circumscribed, radiolucent, unilocular lesion located in
the mandible between the roots of the right lower lateral incisor and Fig. 2 Cystic cavity lined by simple and double squamous epithelia.
canine, with slight divergence of the roots H&E, ×200, original magnification

3. Oral Maxillofac Surg
shape and sclerotic margins, sited on the root lateral surface
of vital teeth, mainly lower premolars [12, 24]. Neverthe-
less, Senande et al. [9] reported a series of 11 cases, of
which eight occurred in the anterior region of the maxilla
and presented an inverted pear-like image. Divergence of
the roots of teeth is a common finding, but root resorption
has not been documented [2, 30]. Although most of the
LPCs did not reach more than 1.0 cm in diameter [4, 27],
there are reports of lesions involving the entire lateral
region of the tooth root [5, 7, 9]. The occurrence of bilateral
LPCs is very rare [21].
The differential diagnosis of LPC includes gingival cyst,
lateral radicular cyst, keratocystic odontogenic tumor,
pseudocysts, and radiolucent odontogenic tumors. The
gingival cyst is a rare soft tissue odontogenic cyst that
Fig. 3 Cystic cavity lined by a double layer of epithelial cells. No
inflammatory cells were observed. H&E, ×400, original magnification
presents similar epidemiological features to the LPC, with a
peak frequency in the sixth decade of life, occurring most
commonly in the mandibular premolar–canine region. In
contrast, the gingival cyst shows a slight female predilection
In the present study, we reviewed the epidemiological [2, 31]. Particularly in LPCs that cause gingival swelling, a
and clinical features of 264 cases of LPC published in the gingival cyst should be excluded using adequate radiographic
English-language literature [1–13, 16–29]. Moreover, these examination and, eventually, with the transoperative finding
data were compared with that presented in the current case. [2, 13, 18]. The radicular cyst may develop along the lateral
Most cases occurred in patients between the fifth and root surface, being named lateral radicular cyst. This lesion
seventh decades of life. The mean age of the available cases occurs due to pulp necrosis and an infected lateral accessory
was 50.8 years (ranging from 18 to 82 years) [1, 3, 5–9, root canal or presents a periodontal origin [2]. The LPC must
11–13, 16–27], similar to the present case, considering that, be distinguished from lateral radicular cysts in order to avoid
in 71 cases, this aspect could not be evaluated in detail [2, unnecessary endodontic therapy. Sometimes, LPC is mis-
4, 10, 28, 29]. The LPC presents a male predilection, with a diagnosed as a chronic lesion of endodontic origin [32].
male/female preponderance of 1.3:1, according to 221 cases Thus, in all cases of radiolucencies located between roots,
where this information was available [1–3, 5–9, 11–13, 16– pulp vitality test and a careful periodontal inspection of the
28]. However, some series did not found a gender involved teeth should be performed. In the present case,
predilection [2, 6–9]. detailed clinical and radiographic exams were carried out.
Regarding the site of the lesion, in 203 of 264 cases of LPC The keratocyst odontogenic tumor (KOT) occurs most
evaluated, this feature was recorded. Of these cases, 150 commonly in the posterior region from the mandible,
(73.9%) were located in the mandible, whereas the maxilla mainly in patients in their second and third decades of life,
was affected in 53 cases (26.1%) [1, 3, 5–9, 11–13, 16–18, despite a peak frequency in the fifth decade that has been
23–29], as occurred in this case, which was sited in the also reported [1, 2]. Although LPC is more frequent in
mandible. All series but one found a maxilla predilection for older patients, KOT comprises one of the main differential
LPC [9]. diagnoses of LPC, since 22.9% of the cases occur in the
Considering the cases located in the mandible, the most root lateral surface [30]. Radiographically, the collateral
affected region is the premolar–canine–incisor area, mainly KOT may present very similar features to LPC, and after
between the premolars [2, 3, 5–8, 11–13, 16–18, 23–26, 29]. the exclusion of an inflammatory origin, the lesion should
Of the evaluated mandibular cases, only five cases occurred be surgically removed and sent for histopathological
in the molar region [3, 7, 9, 29]. As occurred in most analysis to confirm the definitive diagnosis [2, 30, 33].
previously reported cases, the current case was located Other lesions have been reported in the root lateral surface,
between the mandibular canine and lateral incisor. Now, such as ameloblastoma and simple bone cyst, which may
based on the available maxillary cases, most of them show similar features to LPC [33]. In the same way, the
occurred in the anterior region [7, 18, 23, 29]. The maxillary definitive diagnosis is established after histopathological
premolar and molar areas are rarely affected, with seven [7, analysis or surgical exploration, as in simple bone cyst
12, 23] and two cases [7, 23] reported, respectively. cases.
The radiographic appearance of the lesion is a well- Microscopically, LPC presents as a cystic cavity lined by
circumscribed radiolucency, presenting a round or oval a thin layer of epithelium and supported by a connective

4. Oral Maxillofac Surg
tissue. Usually, no inflammatory cells are observed, although 4. Altini M, Shear M (1992) The lateral periodontal cyst: an update.
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Acknowledgments Dr. Silva-Sousa and Dr. Perez are research 22. Ross VA, Craig RM Jr, Vizuete JR (1986) A radiolucent lesion
fellows of the National Council for Scientific and Technological adjacent to the roots of the mandibular right first and second
Development (CNPq). premolars. J Am Dent Assoc 112:235–236
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lateral periodontal cyst and other pigmented odontogenic lesions.
Conflict of interest The authors declare that they have no conflict of Oral Dis 2:299–302
interest. 24. Tolson GE, Czuszak CA, Billman MA, Lewis DM (1996) Report
of a lateral periodontal cyst and gingival cyst occurring in the
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