Malignant change in a dentigerous cyst

Primary intraosseous squamous cell carcinoma arising in dentigerous cyst: Report of 2 cases and review of the literature

Dentigerous cysts are one of the most common odontogenic cysts of the oral cavity. Odontogenic cysts can give rise to a variety of neoplasms. Carcinoma arising in a dentigerous cyst is extremely rare, with a review of literature showing near 30 cases. The present report describes 2 cases of primary intraosseous squamous cell carcinoma originated from a dentigerous cyst. The first one refers to a 57-year old female with a persistent lesion in the left retromolarregion and diagnosed with squamous cell carcinoma originated fromthe incomplete excision of the lower third molar follicle during its surgical extraction. The second case describes the case of an 18-year old male with an impacted upper canine with previous history of infection and swelling of the oral cavity. The histopathological study revealed the malignization of the follicle surrounding the dental crown. These two cases confirmed the importance of the histopathological study of all the tissue samples obtained from surgical procedures. Although the development of a malignant lesion from a dentigerous cyst is rare and its clinical-radiological features are apparently innocuous, this entity should be considered as a differential diagnosis.

Key words:Dentigerous cyst, odontogenic cyst, squamous cell carcinoma, primary intraosseous squamous cell carcinoma, odontogenic carcinoma.

Odontogenic ghost cell carcinoma: a case report with immunohistochemical and ultrastructural characterization

The odontogenic ghost cell tumor (OGCT) is the rare, neoplastic variant of the calcifying odontogenic cyst (COC). To date, there have been only four reports of malignant OGCTs, in five patients. We report an additional case of a malignant odontogenic ghost cell tumor that involved the right maxilla of a 20-year-old man. Our report includes its immunocytochemical and ultrastructural characterization.

Carcinoma arising in a dentigerous cyst with neck metastasis

BACKGROUND

Squamous cell carcinoma arising in a dentigerous cyst is extremely uncommon. The diagnosis of carcinoma arising in a dentigerous cyst requires microscopically that an area of benign cystic epithelium is observed to transition into squamous cell carcinoma. In the present case, the patient was diagnosed with squamous cell carcinoma of the neck with an unknown primary. The primary site was found to be the follicular space associated with the right mandibular third molar.

METHODS

Light microscopic studies were performed to arrive at the final diagnosis.

RESULTS

Transition of the epithelial lining of the dentigerous cyst to squamous cell carcinoma was observed in multiple fields.

CONCLUSIONS

The present case demonstrates that odontogenic cysts have to be considered a possible source of metastatic disease.

Squamous cell carcinoma arising in a residual cyst. A case report

A case of squamous cell carcinoma (SCC) arising in a mandibular residual cyst in a 62-year-old man is presented. The treatment included enucleation followed by primary closure. Histologic examination revealed a poorly differentiated SCC in the cyst lining without invasion through the connective tissue wall. Eight and a half years later, the patient was still free from recurrence.

Third molars confusing the diagnosis of carcinoma

The purpose of this study was to describe cases of oral cancer in which the initial presenting symptoms were considered to be due to third molars and in which the underlying carcinoma therefore escaped early diagnosis. Between 1986 and 1990 a total of five cases with squamous cell carcinoma associated with a third molar (impacted, partially or totally erupted, or recently extracted) were treated at our unit. Because of acute or chronic symptoms related to disturbed eruption of third molars, the detection of a simultaneous malignant change and referral were delayed. In conclusion, all third molars, especially impacted, partially erupted, or overerupted ones, should be examined critically, especially if the patient has symptoms.

Respiratory epithelium in an apical periodontal cyst of the mandible

A cyst attached to the apex of a mandibular canine was partly lined with respiratory epithelium. This is an interesting observation for two reasons: (1) The few well-documented instances of this type of epithelium in apical periodontal cysts have been in the maxilla, where a plausible source for the respiratory epithelium for most of them was a breach in the floor of the maxillary sinus. (2) The mandibular location of the cyst reported here indicates that the respiratory epithelium within it was derived through proliferation and metaplasia of the rests of Malassez.

Aggressive (malignant?) epithelial odontogenic ghost cell tumor

Although the calcifying odontogenic cyst (COC) is a well-established pathologic entity, it has been recognized that there is an odontogenic neoplasm with histologic features similar to the COC that has often been diagnosed as COC. Investigators have applied several terms to this neoplasm, but we prefer the term epithelial odontogenic ghost cell tumor (EOGCT). No reports have appeared previously in the literature describing either carcinoma arising in a COC or malignant EOGCT. Three cases are reported here with aggressive growth and histologic features strongly implying a malignant potential, although none is known to have metastasized. Two occurred in the maxilla and one in the mandible. One was discovered 9 years following removal of a typical COC, and another recurred rapidly after excision.

Bilateral maxillary squamous odontogenic tumors and the malignant transformation of a mandibular radiolucent lesion

A case of bilateral squamous odontogenic tumors of the maxilla with concomitant malignant transformation of a mandibular lesion to squamous cell carcinoma is presented. It is the first reported case of squamous odontogenic tumor in coexistence with a malignant tumor.

Primary intraosseous carcinoma of the jaws. Review and update of odontogenic carcinomas

According to the World Health Organization (WHO) classification system, primary intraosseous carcinoma (PIOC) of the jaw is the terminology recommended in lieu of primary intra-alveolar epidermoid carcinoma (PIAEC) of the jaw. Malignification of odontogenic cysts is now considered a separate entity. Therefore, data garnered from previous case series on PIAEC are not applicable to PIOC. This study reviews the literature on PIOC, excluding central carcinoma cases which arose in odontogenic cysts. Twelve cases were found. The PIOC has a predilection for males (3:1), is noted chiefly in adults, occurs most frequently in the mandible, is histologically nonkeratinizing in 58 percent of the cases, and exhibits peripheral palisading in 58 percent of the cases. A plexiform or alveolar pattern was noted in 67 percent of the cases. The prognosis is quite poor, with only 40 percent of the patients surviving more than 2 years. A modification of the WHO classification system to include "ameloblastic carcinoma" is suggested.

Aggressive growth and neoplastic potential of odontogenic cysts: with special reference to central epidermoid and mucoepidermoid carcinomas

An aggressive form of odontogenic cyst known as the keratocyst has been reviewed with a report on the findings of 70 new instances. Recurrence after 2 years of followup was found to be 20%. From both a review of the literature and original cases, carcinomatous and ameloblastomatous transformation in odontogenic keratocysts seems to be an extremely rare phenomenon. Alternatively, epidermoid carcinoma and mucoepidermoid carcinoma arising centrally within the jaws are often associated with other types of dental cycts. Review of 36 instances of central epidermoid carcinoma has disclosed that 75% were associated with a cyst lining; the 2-year survival rate was found to be 53%. Central mucoepidermoid carcinoma was associated with a dental cyst or impacted tooth in 48% of the cases, and enjoyed a 100% 2-year and 5-year survival; however, 2 patients were recorded alive with disease at 4 months and 10 years, whereas another patient succumbed to disease 14 years postoperatively.