Association of simple bone cyst and cemento‐osseous dysplasia: A long‐term follow‐up

Abstract

Cemento‐osseous dysplasia (COD) is a non‐neoplastic, usually asymptomatic condition characterized by the presence of amorphous cement‐like calcifications located exclusively in the tooth‐bearing regions of the jawbone. Simple bone cysts (SBCs) of the jaws are benign intraosseous cavities, empty or filled with serous, serohematic, or blood fluid. They are characterized by the absence of an epithelial lining. COD and SBCs are two distinct lesions of the jaws that have long been described separately in the literature; however, their co‐occurrence remains rare and only a few cases have been reported illustrating this relationship. This association can be considered as a distinct entity since it presents specific epidemiological, clinical, and radiological data. The aim of this article was to report a new case of association between COD and SBC by illustrating a florid COD formation in mandibular SBC detected in a 31‐year‐old patient followed over a period of 11 years.

Although rare, the association between simple bone cysts and cemento‐osseous dysplasia is very important to know. It is essential to be able to establish a correct diagnosis through regular follow‐up to detect clinical and radiological changes of this entity over time and to be able to intervene when necessary.

1. INTRODUCTION

Cemento‐osseous dysplasia (COD) is a benign and usually asymptomatic fibro‐osseous lesion composed of an anarchic mixture of cementum and dysplastic bone that occurs exclusively in the tooth‐bearing regions of the jaw bones. ¹

Being the most common fibro‐osseous lesion of the jaws, COD can be divided into three variants according to The 2017 World Health Organization (WHO) classification of COD: periapical, focal, and florid COD. ²

The SBC was first described by Lucas and Blum in 1929. ³ It was defined by Rushton in 1946 as an intraosseous lesion empty of contents or filled with serous, serohematic, or bloody fluid, surrounded by hard bone walls, without epithelial lining, and without infectious etiology. When present, the cyst lining consists of a very thin and fragile connective membrane. ⁴

These two lesions have been widely described independently; however, the co‐occurrence of SBC with COD remains rare.

Described for the first time by Melrose et al. in 1976, ⁵ many cases of this co‐occurrence have been reported in the literature exposing three types of associations: COD complicated by SBC, SBC complicated by COD, and the presence of concomitant SBCs and COD.

In this case report, we present a florid COD formation in mandibular SBC detected in a 31‐year‐old female patient followed over a period of 11 years.

2. CASE REPORT

A 31‐year‐old female patient with no notable pathological history consulted our Department of Dental Medicine of the Military Hospital of Tunis in 2009 for the management of a mandibular swelling.

The clinical examination revealed a hard, fixed, non‐inflammatory, and painless left mandibular swelling.

The panoramic radiograph showed an osteolytic radiolucent image, plurilocular, extending from the left first premolar to the left third molar region in the mandible.

This image is poorly limited in places. It encompasses the roots of the involved teeth that responded positively to the pulp vitality test, without repressing the lower mandibular canal. The right side was free of lesions (Figure 1). The mandibular CT scan reveals a hypodense, osteolytic, multi‐lobed lesion with buccal bone expansion, which encompasses the roots of the 36, 37, and 38 teeth (Figure 2).

FIGURE 1.

Panoramic radiograph taken in 2009: image of polycyclic radio clarity with ill‐defined, scalloped margins extending from the distal side of 34 to the mesial side of 38. There is no mandibular canal compression.

FIGURE 2.

(A) Axial section, (B) coronal oblique reconstructions: a poorly limited hypodense polycyclic image related to the roots of the left molars. Thinning of the cortical bone can be seen.

This radiological aspect associated with the clinical data would suggest the diagnosis of an ameloblastoma or a keratocyst.

Thus, a surgical management, under general anesthesia, in collaboration with the Department of Plastic and Maxillofacial Surgery, was performed finding an empty intraosseous cavity devoid of epithelial lining. The intraoperative diagnosis of SBC was therefore retained.

On the follow‐up panoramic radiographs, a progressive re‐ossification of the residual cavity was noted (2010) (Figure 3), then the lesion at the level of the left premolar region became more radioopaque with a cemento‐osseous density suggestive of dysplasia; we thought at this stage of a probable dysplastic healing of the SBC (2011) (Figure 4).

FIGURE 3.

Panoramic radiograph of 2010: the left lesion becomes smaller. An aspect of individualized non communicating lesions (arrows). Opacities can be seen which indicate the beginning of ossification of the lesion.

FIGURE 4.

Control panoramic radiograph in 2011: a newly formed radio opacity (arrow) embedded in the radiolucent lesion opposite the premolars.

In 2012, a new osteolytic image of 5 mm of axis appeared on the opposite side next to the 45 tooth (Figure 5). The pulp vitality test on 45 was positive with the absence of any other symptomatology. We thought of the diagnosis of a second localization of the SBC since multiple SBCs can occur in the jawbones, hence the therapeutic abstention and radiological monitoring. On the other side, we noted the absence of re‐ossification of the left lesion especially in the molar area with a tendency to increase in size.

FIGURE 5.

Panoramic radiograph of 2012: an osteolytic lesion appears in relation to the 45 (arrow). The lytic lesion in relation to the left molars becomes more extensive .

In 2013, the patient came back to her follow‐up appointment with a mild, painless, 2‐cm‐long left mandibular swelling with no signs of local infection nor hypoesthesia. No palpable cervical adenopathy was noted. A polycyclic image of mixed appearance extending from the mesial side of 35 to the distal side of 37 was objectified on the panoramic radiograph (Figure 6). A distal carie on the 36 tooth was detected and the patient described only a slight pain provoked by cold.

FIGURE 6.

A panoramic radiograph taken in 2013: a more mixed appearance of the left lesion. The lesions tend to spread and mature.

The diagnoses evoked at this stage were: superinfection of the dysplasia; a diagnosis that was quickly ruled out due to the absence of infectious signs, bone remodeling of a dysplasia in different stages, mature and immature, or recurrence of SBC.

The management carried out was: treatment of dental carie on tooth 36 and abstention in relation to the lesion in the absence of any symptomatology.

A timeline has been elaborated to better explain the chronological evolution of our case (Figure 7).

FIGURE 7.

Timeline: chronological evolution of the radiological appearance of SBC‐associated COD. COD, cemento‐osseous dysplasia; SBC, simple bone cysts.

In 2014, the patient re‐consulted with bilateral mandibular swellings, hard, painful to palpation, and covered with normal skin.

The mandibular CT scan revealed: a right osteolytic lesion related to the 45 and on the left side, a mixed multilocular intraosseous lesion extending from 35 to 38, with opposite the root of the 35, the lesion takes a poorly limited radiolucent aspect. The buccal cortical was thinned (Figure 8).

FIGURE 8.

CT scan performed in 2014 prior to re‐operation: axial sections: a right lytic lesion opposite the 45 and on the left side, an intraosseous cystic lesion opposite the root of 35 with ill‐defined limits associated with a mixed multiloculated lesion opposite 36, 37, and 38. The buccal cortical was thinned.

Given the symptomatology, the patient was re‐hospitalized and proposed for surgical removal of her two lesions. A biopsy was performed on both sides.

Microscopically, the two biopsy samples showed the same aspect: abundant fibrous tissue with a high vascularity. They contain numerous disorganized bone trabeculae without an osteoblastic border.

Histological examination confirms the diagnosis of florid COD.

The patient was then lost to follow‐up for 4 years and returned for a check‐up in 2018. On panoramic, the lesion related to the 45 takes on a mixed appearance and a new radiolucent lesion was noted in front of the 47 tooth which responded positively to pulp vitality tests (Figure 9).

FIGURE 9.

Panoramic radiograph taken in 2018: appearance of a new osteolytic lesion opposite to 47. Maturation of the other lesions with a more radio‐opaque appearance.

Subsequent panoramic radiographs showed a stable appearance of the lesions, with changes in size and density and no evidence of clinical superinfection until 2020 and then she was lost to follow‐up again (Figures 10 and 11).

FIGURE 10.

Panoramic radiograph taken in 2019: multiple diffuse mandibular lesions at different stages of evolution (radiolucent, mixed, radio‐opaque) suggestive of florid cemento‐osseous dysplasia.

FIGURE 11.

Panoramic control radiograph in 2020: florid cemento‐osseous dysplasia of the mandible.

3. DISCUSSION

The association between SBC and COD was initially described extragnathically in long bones.

Indeed, as early as 1958 and for the first time, the presence of cement‐like calcified tissue located in the walls of SBCs of long bones was noted by Jaffe. ⁶

Later, Adler confirmed Jaffe's initial finding by studying the histological appearance of 28 extragnathic SBCs with cemented tissue. The author found that the collected material contained an irregular acellular network of trabeculae; these fibrillar and acellular deposits found had the appearance of typical dental cement. ⁷

The association between COD and SBC in the jawbones was first recognized by Melrose et al. in their 1976 study: of 34 patients with COD 41% (14 patients) had histologically proven associated SBC. ⁵ Since then, only about 50 cases have been reported in the English literature.

SBC is rare in adults, when it occurs it is usually associated with a fibro‐osseous lesion. Horner and Forman ⁸ and Mahomed et al. ⁹ have noted that SBC in the elderly show significant clinicopathological differences from SBC occurring in children and adolescents. SBC associated with COD show a female predilection, which is not surprising since COD is often observed in middle‐aged black women (in the fourth and fifth decades of life). ¹⁰ They also tend to occur in multiple forms, whereas multiple forms are rare in isolated SBC. Isolated SBC tends to heal much better after surgery than that associated with COD. ¹¹

Higuchi et al. ¹² and Mahomed et al., ⁹ in their respective case series, found that all lesions were of mandibular location, which is in full agreement with the data in the literature regarding the predominance of occurrence of the association at the mandibular level; the same finding was stated for our case.

Chadwick et al. in 2011 reported that of 91 SBC patients, 23 subjects (25%) had SBCs associated with COD; they found, through their comparative study, that SBCs associated with COD were more likely to cause cortical thinning, bone expansion, dental root scalloping, loss of periodontal ligament space, as well as loss of lamina dura than solitary SBCs that classically describe these radiological features. ¹³

With regard to etiopathogenesis, several conflicting hypotheses have been put forward regarding the type of association between SBC and COD.

Jaffe suggested that SBC could be the result of an aberration in the development and growth of the dysplastic lesion. ⁶

Miyauchi et al. noted the presence of a prominent capillary network within the proliferating fibrous tissue and throughout the medullary spaces between the newly formed hard tissue trabeculae around the cystic cavity, indicating a potential for cystic lesion formation after the development of COD. ¹⁴

Likewise, Higuchi et al. postulated that cystic changes occurred after the development of COD. ¹²

Similarly, Wakasa et al. reported a case in which SBC formation was observed in the same regions where Florid COD (FCOD) existed 3 years earlier; data that indicate that FCOD precedes SBC formation. Histologically, they found the presence of poor vessels in the fibrous connective tissue adjacent to the cystic cavity, and it was considered that the disordered production of trabeculae in FCOD may lead to obstruction of lymphatic drainage, resulting in cystic degeneration. ¹⁵ The same etiologic hypothesis was stated earlier in 1976 by Melrose et al. ⁵

However, long‐term follow‐up of our case clearly showed the opposite.

Indeed, the formation of histologically proven COD was secondary and occurred in the former site of SBC (the diagnosis of SBC was confirmed intraoperatively). Subsequently through the years, the COD became florid.

In support of our hypothesis, Fischer reported that the presence of fibro‐osseous tissue was secondary and represented a repair of the SBC, ¹⁶ which was suggested for our case regarding dysplastic SBC cicatrization.

Saito et al. proposed in 1992 that when SBC persisted for several years, it could cause erosion of the lamina dura and lead to direct exposure of roots in the cystic cavity, which in turn could trigger cementum formation. ¹⁷

Tomita et al. also found a tendency for lamina dura erosion with associated tooth exposure and resorption in atypical SBC with radio‐opaque lesions. ¹⁸

Actually the association between COD and SBC is part of a larger group of associations; that of non‐epithelial‐lined cysts and benign fibro‐osseous lesions of the jaws.

Indeed, Yeom and Yoon ¹⁹ and Jacomacci et al. ²⁰ described the association between aneurysmal bone cyst and COD.

On the other hand, Hara et al., ²¹ Ferreti et al., ²² and Martini et al. ²³ reported cases of concomitant fibrous dysplasia and SBC.

Despite its clinical rarity, the association of COD and SBC can now be considered as a distinct entity. The two hypotheses discussed above, concerning the chronology of appearance of each lesion, remain valid. It would be interesting to know this co‐occurrence and to better understand its etiopathogeny by carrying out additional histological studies.

4. CONCLUSION

The co‐occurrence of SBC with COD is very important to know, as well as its clinical and radiological features, in order to obtain a correct and timely diagnosis and to avoid over‐treatment, such as unnecessary endodontic treatments or invasive surgeries due to misdiagnosis.

The establishment of an adequate follow‐up is fundamental to ensure a good prognosis.

AUTHOR CONTRIBUTIONS

Fatma Hajjami has written the manuscript. Hend Ouertani has participated in the design, the acquisition of clinical data as well as the revision of the manuscript. Hichem Brahem managed the patient surgically; Hichem Mehrez participated in the collection of bibliographic data. The other authors discussed the results by revising critically for important intellectual content and have given final approval of the version to be published. All authors approved the final draft of the manuscript.

FUNDING INFORMATION

None.

CONFLICT OF INTEREST STATEMENT

The authors declare that there is no conflict of interest regarding the publication of this article.

ETHICS STATEMENT

Our institution does not require ethical approval for reporting individual cases or case series.

CONSENT

Written informed consent was obtained from the patient for his anonymized information to be published in this article.

Hajjami F, Ouertani H, Brahem H, Mehrez H, Blouza I, Khattech MB. Association of simple bone cyst and cemento‐osseous dysplasia: A long‐term follow‐up. Clin Case Rep. 2023;11:e7161. doi: 10.1002/ccr3.7161

DATA AVAILABILITY STATEMENT

The datasets generated during the current study are not publicly available but are available from the corresponding author on reasonable request.