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Year : 2020  |  Volume : 11  |  Issue : 4  |  Page : 224-228

Periapical pocket cyst of anterior maxilla: A case report and literature review

Department of Oral Pathology and Microbiology, SRM Dental College, SRMIST, Chennai, Tamil Nadu, India

Date of Submission19-Nov-2019
Date of Acceptance12-Dec-2020
Date of Web Publication05-Feb-2021

Correspondence Address:
Dr. Mounika Sathiya
Department of Oral Pathology and Microbiology, SRM Dental College, SRMIST, Ramapuram, Chennai - 600 089, Tamil Nadu
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DOI: 10.4103/srmjrds.srmjrds_118_20

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Periapical cyst is an inflammatory odontogenic cyst of endodontic origin. It is called as periapical true cyst when the cyst is epithelium lined, closed pathological cavity or periapical pocket cyst when the epithelium lined cavity is continuous with the root canal of the affected tooth. Majority of the periapical cyst has the potential to heal after conventional root canal treatment. Large, true cysts respond less favorably to nonsurgical treatment. We present a case of 24 year old male patient who presented with a swelling in the upper lip region. A diagnosis of periapical cyst was made based on clinical and radiographic features. Intraoperatively, the cyst was found to be continuous with the root canal. Considering the histopathological features, a final diagnosis of periapical pocket cyst was given.

Keywords: Anterior maxilla, case report, periapical cyst, pocket cyst

How to cite this article:
Sathiya M, Shanmugalingham H, Balasubramanian H, Harisudhan C J, Harini S, Divya B. Periapical pocket cyst of anterior maxilla: A case report and literature review. SRM J Res Dent Sci 2020;11:224-8

How to cite this URL:
Sathiya M, Shanmugalingham H, Balasubramanian H, Harisudhan C J, Harini S, Divya B. Periapical pocket cyst of anterior maxilla: A case report and literature review. SRM J Res Dent Sci [serial online] 2020 [cited 2021 Feb 25];11:224-8. Available from:

  Introduction Top

The periapical cyst is a chronic inflammatory cystic lesion characterized by a pathologic cavity lined either partially or completely by nonkeratinized stratified squamous epithelium. It is the most common odontogenic cyst of inflammatory origin.[1] The cyst is commonly associated with pulpal necrosis, leading to inflamed periapical tissues. Clinically, the cyst is asymptomatic unless infected. Radiographically, it presents as a well-defined unilocular radiolucency. Occasionally, multilocular radiolucent radicular cysts are also reported.[2],[3],[4] These cysts are commonly found at the apices of the involved teeth; however, they may also be found on the lateral aspects of the roots in relation to the lateral accessory root canals. Periapical cysts can be classified as true cyst or pocket cyst. In true cysts, the cystic cavity is completely surrounded by epithelium, whereas in pocket cysts, the cavity is surrounded by epithelium, which is in continuum with the apical foramen. These two types of cysts differ in their response to conventional root canal therapy. True cysts are independent of the irritants present in the root canal and are less responsive to root canal treatment.[5]

We report a case of 24-year-old male patient with a swelling in the anterior maxilla diagnosed histopathologically as periapical pocket cyst.

  Case Report Top

A 24-year-old male presented with a complaint of pain and swelling in the upper left lip region for 3 months. The patient had a history of trauma before 10 years. The patient had undergone root canal treatment in upper anterior teeth 6 months back. The swelling was smaller in size and progressed to a bigger size during the past 3 months. The associated pain was mild, which interfered with his daily activities. On extraoral examination, there was a swelling present on the upper lip and nasolabial region extending from the upper alveolus to beneath the infraorbital margin, measuring 3 cm × 3 cm in dimension [Figure 1]. On intraoral examination, a swelling in relation to 21, 22, 23, 24 with tenderness and redness was observed.
Figure 1: Extraoral image showing facial asymmetry

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Radiographic examination revealed unilocular radiolucency with well-defined radiopaque border in relation to the periapical region of 21, 22 [Figure 2] and [Figure 3]. Based on the clinical and radiographic findings, a provisional diagnosis of the periapical cyst was made. With the proper informed consent, cyst enucleation was performed [Figure 4]. The soft-tissue specimens were received in 10% formalin solution for histopathological examination. The specimens were irregular in shape with firm consistency measuring about 2.3 cm × 1.5 cm approximately [Figure 5]. Histopathological examination revealed a cystic lumen lined by non-keratinized stratified squamous epithelium surrounded by a fibrous connective tissue wall. The epithelium appeared hyperplastic and exhibited an arcading pattern [Figure 6]. The connective tissue wall was fibrocellular in nature with numerous inflammatory cells, predominantly lymphocytes and plasma cells [Figure 7]. Blood vessels engorged with RBCs were also present. Histopathological findings confirmed the periapical pocket cyst. On follow-up visits, the healing was found to be satisfactory.
Figure 2: Intraoral periapical radiograph revealing radiolucency in relation to 21, 22

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Figure 3: Orthopantomogram revealing unilocular radiolucency associated with root canal treated 21, 22

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Figure 4: Intraoperative image showing the cystic space associated with roots of 21, 22

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Figure 5: Gross specimen measuring about 2.3 cm × 1.5 cm approximately

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Figure 6: Low power magnification revealing cystic lumen lined by parakeratinized stratified squamous epithelium

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Figure 7: Higher power magnification revealing chronic inflammatory infiltrate in the connective tissue wall

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  Discussion Top

Periapical cyst is the most common odontogenic cyst, accounting for 55% of odontogenic cysts and 52%–68% of all of the cysts of the jaw in humans.[6] Periapical cysts are otherwise called radicular cyst or apical periodontal cyst. These cysts are observed mostly in the third and fourth decades of life, and they have shown male predilection.[6] The most common etiology is dental caries with pulp involvement.[1],[2] In accordance with this data, the present case is the report of the radicular cyst in a male patient. In 1980, Simons used the term bay cyst to describe the radicular cyst with epithelium lined cavity open to the root canal, which was later renamed as periapical pocket cyst due to its resemblance to the marginal periodontal pocket.[7] It is hypothesized to be an extension of the root canal acting as a “death trap” to seal the necrotic tissue and microbial products from the adjacent, normal periapical tissues. The pocket cyst can be distinguished from true cyst only after taking serial histologic sections.

Periapical cysts are known to develop as a complication of pulpal necrosis, periapical granuloma. The lining is derived from epithelial cell rests of Malassez. The etiopathogenesis and biology of this cyst still remain unclear and there are three phases in the formation of true cyst.[8] In the first phase or the phase of initiation, there is the proliferation of dormant epithelial cell rests of Malassez in response to trauma or infection. The second phase is the cyst formation phase which has been explained by diverse theories, as represented in [Figure 8].[7],[9] The third phase is the cyst enlargement phase, which is believed to happen by the process called osmosis. Due to increase in the osmotic pressure within the cystic cavity, there is the ingress of tissue fluids causing increased intracystic pressure, which in turn leads to bone resorption and cyst expansion.
Figure 8: Flowchart depicting the pathogenesis of periapical cyst formation

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Radiographically, the radicular cyst is unilocular with well-circumscribed border and it should be at least 1 cm in diameter to be distinguished from the normal follicular space.[10] There are other odontogenic lesions resembling radicular cyst radiographically; hence, a thorough microscopic evaluation is essential to distinguish them. Microscopically, the cystic cavity is lined by nonkeratinized stratified squamous epithelium of variable thickness. The connective tissue of the cyst wall contains dense inflammatory infiltrate predominantly comprised of chronic inflammatory cells such as lymphocytes, plasma cells, macrophages intermixed with neutrophils, rarely mast cells and eosinophils.[11] Plasma cells produced by the B-lymphocytes, participate in the host's defense system and accumulate at the sites of chronic inflammation. Rushton bodies are seen exclusively in the odontogenic cysts, and histologically, four types can be seen they are, one is linear, straight or curved and are hair pin-like, second is like broken pieces of plate, third is circular[12] and the fourth is elongated type, lining cleft like spaces which are cholesterol clefts.[13] Russell bodies represent aggregates of immunoglobulins, which are hyperproduction of normal secretory protein by plasma cells.[14],[15] Russells bodies are seen in different lympho-proliferative diseases such as multiple myeloma, cutaneous leishmaniasis, and chronic inflammatory periapical lesions.[16],[17],[18] Histologically, Russells bodies can be differentiated by their typical homogenous nature, round shape and per-iodic acid Schiff reagent positivity, which are not observed in Rushton bodies.[19] In our case, intraoperatively, the cystic lumen was found to be continuous with the root canal and histologically, the cyst was not a closed cavity. Correlating the clinical, radiographic and histopathological features, a final diagnosis of the periapical pocket cyst was given.

The surgical approach to radicular cystic is root canal treatment or enucleation and curettage. Most of the radicular cysts have been successfully managed with nonsurgical endodontic treatment. The success of endodontically treated tooth depends on the quality of the restoration. In our case, the periapical radiolucency associated with nonvital teeth had progressed to periapical cyst as the teeth were not restored. Periapical true cysts respond less favorably to conventional root canal treatment. Surgical management is indicated for true cyst and for cyst >2 cm in diameter.[20] If the radicular cysts are left untreated, then the inflammatory process may undergo an acute exacerbation and develop rapidly into abscess that may then proceed to a cellulitis or form a draining fistula or swelling, tenderness, and tooth mobility. Studies show the recurrence rate of the radicular cyst to be 3.1% and has the least recurrence rate if the follow-up is proper when compared to the other odontogenic cysts.[21]

  Conclusion Top

The periapical pocket cyst is the most common type of periapical cyst. The outcome of the histopathological evaluation plays a major role in determining the appropriate treatment plan for the lesion. Most of the periapical pocket cysts can be successfully managed with nonsurgical endodontic treatment. Restoration of the endodontically treated tooth is essential to elude bacterial contaminants and failure of which can result in progression of the lesion as seen in our case.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.

  References Top

Johnson NR, Gannon OM, Savage NW, Batstone MD. Frequency of odontogenic cysts and tumors: A systematic review. J Investig Clin Dent 2014;5:9-14.  Back to cited text no. 1
Shivhare P, Singh A, Haidry N, Yadav M, Shankarnarayan L. Multilocular radicular cyst – a common pathology with uncommon radiological appearance. J Clin Diagn Res 2016;10:Zd13-Zd15.  Back to cited text no. 2
Armbrecht EC, Waterman WA. Multilocular radicular cysts of the mandible. Oral Surg Oral Med Oral Pathol 1952;5:827-9.  Back to cited text no. 3
Krishnamurthy V, Haridas S, Garud M, Vahanwala S, Nayak CD, Pagare SS. Radicular cyst masquerading as a multilocular radiolucency. Quintessence Int 2013;44:71-3.  Back to cited text no. 4
Nair PN. New perspectives on radicular cysts: Do they heal? Int Endod J 1998;31:155-60.  Back to cited text no. 5
Noda A, Abe M, Shinozaki-Ushiku A, Ohata Y, Zong L, Abe T, et al. A bilocular radicular cyst in the mandible with tooth structure components inside. Case Rep Dent 2019.  Back to cited text no. 6
Ramachandran Nair PN, Pajarola G, Schroeder HE. Types and incidence of human periapical lesions obtained with extracted teeth. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1996;81:93-102.  Back to cited text no. 7
Koju S, Chaurasia NK, Marla V, Niroula D, Poudel P. Radicular cyst of the anterior maxilla: An insight into the most common inflammatory cyst of the jaws. J Dent Res Rev 2019;6:26.  Back to cited text no. 8
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García CC, Sempere FV, Diago MP, Bowen EM. The post-endodontic periapical lesion: Histologic and etiopathogenic aspects. Med Oral Patol Oral Cir Bucal 2007;1;12:E585-90.  Back to cited text no. 9
Ricucci D, Mannocci F, Ford TR. A study of periapical lesions correlating the presence of a radiopaque lamina with histological findings. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:389-94.  Back to cited text no. 10
Santos LC, Vilas Bôas DS, Oliveira GQ, Ramos EA, Gurgel CA, dos Santos JN. Histopathological study of radicular cysts diagnosed in a Brazilian population. Braz Dent J 2011;22:449-54.  Back to cited text no. 11
Rushton MA. Hyaline bodies in the epithelium of dental cysts. Proc R Soc Med 1955;48:407-9.  Back to cited text no. 12
Morgan PR, Johnson NW. Histological, histochemical and ultrastructural studies on the nature of hyalin bodies in odontogenic cysts. J Oral Pathol 1974;3:127-47.  Back to cited text no. 13
Welsh RA. Electron microscopic localization of Russel bodies in human plasma cells. Blood 1960;16:1307-12.  Back to cited text no. 14
Paik S, Kim SH, Yang WI, Lee YC. Russel body gastritis associated with helicobacter pylori infection: A case report. J Clin Pathol 2006;59:1316-9.  Back to cited text no. 15
Blom J, Mansa B, Wiik A. A study of Russel bodies in human monoclonal plasm cells by means of immunofluorescence and electron microscopy. Pathologica Microbiologica Scandinavica Section A Pathology1976;84:335-49.  Back to cited text no. 16
Maldonado JE, Brown AL Jr, Bayrd ED, Pease GL. Cytoplasmic and intranuclear electron-dense bodies in the myeloma cell. Arch Pathol 1966;81:484-500.  Back to cited text no. 17
Barbareschi M, Mariscotti C, Missoni E, Morelli R. Russell bodies in New World cutaneous leishmaniasis. Pathologica 1985;77:87-90.  Back to cited text no. 18
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Myoung H, Hong SP, Hong SD, Lee JI, Lim CY, Choung PH, et al. Odontogenic keratocyst: Review of 256 cases for recurrence and clinicopathologic parameters. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:328-33.  Back to cited text no. 21


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7], [Figure 8]


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