Journal of Oral and Maxillofacial Pathology

: 2019  |  Volume : 23  |  Issue : 4  |  Page : 78--82

Pigmented calcifying cystic odontogenic tumor associated with compound odontoma: Report of a rare case and review

BR Premalatha, HS Sreeshyla, Priyanka Nitin, Usha Hegde 
 Department of Oral Pathology and Microbiology, JSS Dental College and Hospital, JSS Academy of Higher Education and Research, Sri Shivarathreeshwara Nagar, Mysuru, Karnataka, India

Correspondence Address:
B R Premalatha
Department of Oral Pathology and Microbiology, JSS Dental College and Hospital, JSS Academy of Higher Education and Research, Sri Shivarathreeshwara Nagar, Mysuru - 570 015, Karnataka


Calcifying cystic odontogenic tumor (CCOT) is a rare lesion accounting for only 2% of all odontogenic cysts and tumors. CCOTs can occur alone or in association with other odontogenic tumors such as odontomas. Pigmented intraosseous odontogenic lesions are rare. Among them, pigmented CCOT is known to occur with greater frequency. Only six cases of combination of pigmentation CCOT associated with odontoma have been reported in the literature. We herein present such a rare case occurring in the maxillary anterior region in a 13-year-old female patient.

How to cite this article:
Premalatha B R, Sreeshyla H S, Nitin P, Hegde U. Pigmented calcifying cystic odontogenic tumor associated with compound odontoma: Report of a rare case and review.J Oral Maxillofac Pathol 2019;23:78-82

How to cite this URL:
Premalatha B R, Sreeshyla H S, Nitin P, Hegde U. Pigmented calcifying cystic odontogenic tumor associated with compound odontoma: Report of a rare case and review. J Oral Maxillofac Pathol [serial online] 2019 [cited 2022 Jul 1 ];23:78-82
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The calcifying odontogenic cyst (COC) was first described as a distinct entity by Gorlin et al. (1962) and Gold (1963). It is a rare lesion accounting for only 2% of all odontogenic cysts and tumors.[1] COC/calcifying cystic odontogenic tumor (CCOT) is a benign cystic neoplasm of odontogenic origin which demonstrates ghost cells in the epithelial component. This tumor sometimes mimics the features of a cyst clinically and radiographically, but histopathologically as well as behavior-wise shows the features of a tumor.[2]

Various terms have been used for the description of this lesion such as COC, CCOT, keratinizing COC, calcifying ghost cell odontogenic tumor, dentinogenic ghost cell tumor, epithelial odontogenic ghost cell tumor, odontogenic ghost cell tumor and odonto-COC.[1]

Clinically, several variants are seen, namely, cystic and neoplastic variants and peripheral and central types. Rare cases of malignant transformation have also been reported.[1] CCOTs can occur alone or in association with other odontogenic tumors such as odontomas, adenomatoid odontogenic tumors, ameloblastic fibroma, ameloblastic fibro-odontoma and ameloblastomas.[1],[2] Among these, odontoma with CCOT is the most common and presents in 24% of CCOTs. Histopathologically, very rare cases of CCOT with melanin pigmentation[1] and clear cells[3] are also reported. Only six cases of CCOT association with odontomas presenting with pigmentation are reported in the literature.[4]

A rare case of the combination of odontoma associated CCOT occurring with pigmentation is presented here.

 Case Report

A 13-year-old female patient reported to the hospital with a complaint of forwardly placed teeth. The patient's medical, dental and family histories were noncontributory. On clinical examination, 12 and 13 were found to be missing and 53 was over-retained.

On routine radiographic examination, a well-defined mixed radiolucent-radiopaque lesion in relation to 12 measuring 1 cm × 1 cm with radiolucent rim and an impacted 13 were incidentally noted. The radiopaque material had a density similar to enamel and dentin suggesting tooth-like mass [Figure 1]. A provisional diagnosis of compound odontoma with impacted 13 was made.{Figure 1}

Excisional biopsy was performed in relation to the anterior labial region of 12 and 13 under local anesthesia, and follicle-like tissue encapsulating pieces of small calcified masses were obtained from the surgical procedure. Pathological gross findings revealed multiple soft- and hard-tissue bits. The soft-tissue bits were creamish-white in color, irregular in shape and measured 2 cm × 1.8 cm × 0.3 cm together. Hard tissue bits were multiple, irregularly shaped with tooth-like appearance and measured together 1.8 cm × 1.4 cm × 0.6 cm.

Microscopic examination of hematoxylin and eosin (H&E) stained soft-tissue sections revealed cystic epithelial lining with basal layer of ameloblast-like cells and suprabasal stellate reticulum-like cells. Focal areas of ghost cell keratinization associated with epithelial lining were noted. Few ghost cells showed calcification. Melanin pigmentation was noted focally within few ghost cells and few lining cells. The connective tissue capsule revealed fine collagen bundles, scattered inflammatory cells, spherules of calcifications, odontogenic cell rests and focal areas of melanin pigmentation [Figure 2]. Microscopic examination of decalcified, H&E stained hard-tissue sections revealed calcifications resembling dentin and cementum, with in a loose fibrous tissue. The ghost cells were positive for Van Gieson special stain [Figure 3]. Fontana–Masson special stain was carried out to confirm the presence of melanin pigmentation [Figure 4].{Figure 2}{Figure 3}{Figure 4}

A final diagnosis of pigmented CCOT associated with compound odontoma was arrived at due to the presence of well-developed denticles within the small cystic structure lined by typical odontogenic epithelium based on the criteria for the diagnosis of CCOT by the World

Health Organization (WHO). The postoperative course was uneventful. The patient is currently under regular follow-up.


COC/CCOTs are rare odontogenic lesions. They may be arising from odontogenic epithelial remnants within the jaw or gingiva.[1] Controversies and confusions have always accompanied this variety of lesions. Many classifications have been proposed and revised. However, disagreements in the terminology exist because there are two different schools of thought regarding their biological nature, the monistic and the dualistic concept.[5] At present, a dualistic concept is highlighted to classify this group of lesions. Over the years, it has become clear that COC has a number of variants including features of a benign odontogenic tumor. In 1971, the WHO described the lesion as a nonneoplastic cystic lesion and preferred to use the term COC. In 1992, the WHO classified this lesion under odontogenic tumors but continued to use the term COC. In 2005, the WHO renamed the lesion as CCOT.[2]

Clinically, no sex or racial predilection has been identified. There is the equal frequency in both the jaws. COC may occur at any age with peaks in the second and third decades (mean age: 33 years). It is predominantly a central lesion; however, 13%–30% of cases have appeared as peripheral lesions. The cystic forms comprise 86%–98% but the neoplastic variants accounting for only 2%–16% of cases. Radiographically, CCOTs are well defined and appear as a uni/multilocular radiolucency with calcifications of variable density noted in one-third to half of the cases. The frequency of associated impacted teeth is 10%–32%. Multiple impacted teeth are also a well-known feature of CCOT. The roots of adjacent teeth are displaced or resorbed. The cortical bone is thinned, expanded or perforated.[1],[2] The radiographic features of our case comply with the available literature, being a well-defined mixed radiolucent-radiopaque lesion with a radiolucent rim and associated impacted canine in the anterior maxillary region.

Histopathologic features include encapsulated lesion with a cystic lining composed of an outer layer of a columnar basaloid odontogenic epithelium and an inner layer resembling stellate reticulum of the enamel organ. Characteristic features for CCOT include the presence of ghost cells and/or calcifications within the cyst lining or fibrous capsule.[1],[2]

CCOT associated with odontoma (CCOTaO) is reported in 24% of CCOTs. CCOTaO presents a female predominance with a ratio of 2:1. The highest incidence occurs during the second decade with a mean age of 16 years, and the most frequent site of occurrence is the maxilla (61.5%).[1] Our case, in a 13-year-old female patient with the lesion situated in the maxilla; is in agreement with the age, sex and site predisposition of CCOTaO.

Radiographically, it appears as a mixed radiolucent-radiopaque lesion (80.5%). Microscopically, the epithelial components in CCOTaO are identical to simple CCOT, but the former presents tooth-like structures that appear to be an integral part of the lesion.[6] Hirshberg proposed CCOTaO to be regarded as a separate entity and suggested the term “odontocalcifying odontogenic cyst,” due to the unique histologic features, female predilection, significant presentation in younger age group and predominant occurrence in the maxilla.[7] Our case, clinically, radiographically and histopathologically can be considered under Hirschberg's description of “odontocalcifying odontogenic cyst.”

Several possibilities are suggested about the pathogenesis of CCOTaO. One possibility is that CCOT and odontoma may represent coincidental juxtaposition. Other investigators suggest that CCOT develops secondarily from odontogenic epithelium that is involved in the formation of the odontoma. However, it also has been suggested that the odontoma develops secondarily from lining epithelium of CCOT.[6] The treatment of CCOTaO consists of conservative enucleation and the prognosis is excellent. Recurrence after conservative therapy is uncommon.[1]

Pigmented calcifying cystic odontogenic tumor

The occurrence of pigmented odontogenic lesions is rare. Han et al. found 47 cases reported in English literature since 1961. The most commonly recognized pigmented odontogenic lesion is CCOT.[7] Özlük et al. in their literature review found a total of 21 cases of pigmented CCOT. The mean age of those patients was 22.8 with 12 of the patients being females. The localization of the tumors, whether to the mandible or maxilla, did not differ significantly. Moreover, only six of the pigmented CCOT cases were associated with odontomas.[4] Our case is the seventh to be reported in the literature.

Other pigmented odontogenic lesions reported in the literature are lateral periodontal cyst, ameloblastic fibrodentinomas, adenomatoid odontogenic tumors and odontogenic keratocysts. Although the lesion type differs, histochemical, immunohistochemical and ultrastructural methods used in studies demonstrated that the pigment is always melanin.[4] The origin of melanocytes present in odontogenic lesions is unknown leaving room for speculations. Their pathologic significance is still of interest. As described in previous reports, most of the patients were Blacks and Asians, thereby implicating racial pigmentation as an important factor.[7] Melanocytes which are normal residents in the oral mucosa are also found in dental lamina or tooth bud of the fetuses[8] more commonly so in pigmented races.[7] Odontogenesis is a complex process resulting from the reciprocal and close interactions between oral epithelium and cranial neural crest-derived ectomesenchyme. It might not be surprising that melanocytes, which are also of neural crest origin, may be present in the dental lamina and odontogenic lesions.[7] The embryologic fact that both melanocytes and dental germs are formed at 5–6 weeks of embryonic life makes it very likely that the former erratically gains entrance to the latter.[9] Another possibility suggested is that a few portions of lesional odontogenic tissue could have the potential for neuroectodermal differentiation under certain circumstances.[7]

An interesting observation to be noted is that melanin-containing intraosseous lesions, with the exception of malignant melanoma metastases, are all localized in the jaw bone. The pathogenesis of this localization is speculative. It is generally known that melanocytes are present in clinically nonpigmented oral mucosa; therefore, the presence of melanocytes can be anticipated in odontogenic lesions since the dental lamina originates from the primitive oral lining. It is a striking feature that all pigmented odontogenic lesions, but not cysts, have an epithelial component accompanied by a mesenchymal component with dentin formation and calcification. Some factors such as the presence of mesenchymal component or the hard tissue formation, which can activate the melanocytes already present in the epithelium, might have played a role. More investigations are required to throw light on the origin of melanocytes in odontogenic lesions.[4]

Pigmented compound odontoma can be considered as a differential diagnosis due to the presence of ghost cells with subsequent calcification and that the occurrence of odontogenic epithelium is not rare in odontomas. Combination lesions should also be expected because the odontogenic epithelium in different areas might undergo variable degrees of differentiation and degeneration. In reality, the differentiation of CCOTaO from odontoma is difficult and subjective. There seems to be a mere difference in clinical behavior and growth potential between these two lesions and the controversy is merely of academic interest. The treatment for both lesions is conservative enucleation and the recurrence is very rare.[7]

CCOT is usually treated by enucleation and curettage. It is emphasized that microscopic evaluation of soft-tissue associated with odontoma is important; because in situ ations where the diagnosis is dentigerous cyst, CCOT or ameloblastic fibroma, conservative surgical removal of lesion is recommended, but if soft-tissue component happens to be ameloblastoma, more radical treatment and longer follow-up are needed. The recurrence of CCOT is not common, and the prognosis is excellent.[1] Malignant transformation of a preexisting benign CCOT is extremely uncommon.[5]


With this case report of pigmented CCOT associated with compound odontoma, we add to the rare literature existing on pigmented odontogenic lesions.

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.


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