Diagnosis and treatment of metastatic ameloblastoma

Effectiveness of molecular-targeted chemotherapy in ameloblastomas: A systematic review

Ameloblastoma is a benign, locally aggressive neoplasm that needs extensive surgical resection. The goal of this article is to obtain an in-depth review of benign ameloblastomas to determine the available level of evidence and the possible benefit of targeted therapeutics for the treatment of ameloblastoma and BRAF V600E mutation in ameloblastoma. An electronic literature search was conducted according to PRISMA guidelines in PubMed/MEDLINE, EBSCO, and Web of Science for eligible studies published between 1975 and 2021. The systematic review is registered with INPLASY (INPLASY202260018). The review included 2 case series and 17 case reports. The histopathological type, anatomic location, expression of BRAF mutation, additional mutations, and molecular-targeted therapies of the 19 reviewed articles were summarized and tabulated. Interestingly, the majority of the primary site of ameloblastoma was located in the mandible (80.9%) compared to the maxilla (17%). The tumour size was reported in nine of the included studies. Most of the included studies in the review exhibited ameloblastoma with BRAF V600E mutations and responded to molecular-targeted therapies. Molecular therapies employing BRAF and/or MEK inhibitors in ameloblastoma with BRAF V600E mutations proved to be an appropriate treatment based on the limited available evidence. It is essential further to deepen our understanding at the clinical and molecular level to enhance the precision of management of ameloblastoma.

Ameloblastoma and Intracranial Involvement: The Current Challenge of the Radical Surgical Treatment. Comprehensive Review of the Literature and Institution experience

Background

Ameloblastoma (AMBL) is an odontogenic tumor, considered to be benign, but aggressive, whose principal risk is a recurrence. The growth can be enormous, and it can extend into the intracranial compartment with serious consequences.

Purpose

The intracranial involvement of AMBL is rare, and it may require an extensive surgery. Although it is a rare condition for the neurosurgeon to treat, knowing this condition can lead to a significant increase in survival for these patients.

Methods

A case of a 56-year-old woman presented with a history of recurrent left maxilla AMBL with intracranial extension and dural involvement of the anterior and medial cranial fossa is reported, followed by a systematic review of the literature with the aim to identify the best surgical treatment.

Results

A total of 32 cases were included in the qualitative analysis. Management is varied and often not described, resulting in an almost complete lack of information and indications for treatment. Radical surgery tends to yield the best outcomes, and it is recommended to have adequate surgical margins when possible.

Conclusions

Intracranial involvement from AMBL compartment is an uncommon manifestation of this rare pathology, but which deserves to be treated in a multidisciplinary way in order to ensure maximum surgical radicality. Recurrence reflects failure of the primary surgical resection. If recurrence is the major consideration, surgeons are encouraged to select radical surgery. Whenever a follicular-type maxillary AMBL is diagnosed, it is advisable to check for intracranial spreading and distant metastases during follow-up.

Malignant Ameloblastoma with Hepatic Metastasis in a 38-Year-Old Haitian Woman

BACKGROUND Primary malignant ameloblastoma is a very rare tumor of the dental lamina epithelium. Similar to the benign ameloblastoma, the mass is without significant histological atypia, but the malignant type may present with metastases, most commonly to the lungs. The average age of diagnosis is 34 years, and the malignancy affects men and women equally. The tumors often present with an insidious growth and have a median survival from time of diagnosis of 17.6 years. Due to the rarity of this lesion, a standard of care has not yet been established. CASE REPORT A 38-year-old Haitian woman, who initially presented with a large primary malignant ameloblastoma of the angle of the mandible, experienced a recurrence in the floor of the mouth 30 months after surgical resection. In 2018, 2 years after the removal of the recurrent tumor, the patient presented with ascites, right-sided abdominal pain, weight loss, and a palpable liver mass. Laparoscopic exploration demonstrated a complex lateral right liver lobe cyst, suspicious for parasitic infection. Cytological analysis showed positive staining for cytokeratin 5/6, P63, and CD56, indicative of metastatic ameloblastoma of the liver. Consistent cell morphology from the primary tumor and liver cyst was also noted. Following drainage of the cyst, the patient returned to Haiti, where she died in 2020. In Haiti, she lacked appropriate local medical care, leading to the severe progression of her initial primary ameloblastoma and disease recurrence. CONCLUSIONS Malignant ameloblastoma accounts for less than 2% of all odontogenic tumors, as the benign variant is much more common. Distant metastases of these lesions are rare; to date, few cases have presented with hepatic metastases.

Pure endoscopic transsphenoidal treatment of skull base ameloblastoma with intracranial extension: Case report and literature review

Background:

Ameloblastoma is a benign locally invasive lesion that represents 1% of all oral tumors. Epidemiological characteristics are variable in the literature. The most common origin sites are mandible and maxilla. Rarely presents metastasis, but the skull base, lymph nodes, and the lung are described as metastatic sites. Low recurrence rates were reported by the authors when surgical treatment achieved complete resection.

Case Description:

A female patient, 19 years old presenting moderate headache associated with nausea, vomiting, left facial hypoesthesia, and low visual acuity. Resonance image showed a heterogeneous expansive solid formation in sphenoid bone and clivus with neoplastic aspect. Signs of dissemination due to contiguity and invasion of skull base structures, especially cavernous sinus and internal carotid artery, determining also compression of the brainstem. First, an endoscopic biopsy was performed with otorhinolaryngology service. The pathological study showed histological characteristics of ameloblastoma. After, the patient was submitted to endoscopic surgery for resection of tumor.

Conclusion:

Ameloblastoma is a rare tumor with benign behavior and slow growing. It arises from odontogenic epithelium and accounts 1% of all oral tumors. The mandible and maxilla are the most common sites of origin. Ameloblastoma with intracranial involvement is a rare presentation with few literature reviews. A long time illness course and multiple surgeries are characteristics present in the majority of cases described. Total resection surgery is the treatment of choice and endoscopic transnasal resection is a viable option.

Metastatic pulmonary ameloblastoma misdiagnosed as primary squamous cell carcinoma preoperatively

Ameloblastomas are rare odontogenic epithelial tumors that occur mainly in the mandible. Despite their benign histologic appearance, they are locally aggressive with a high recurrence rate. However, a metastasizing ameloblastoma has been rarely reported. According to the current World Health Organization classification system, the definitive diagnosis of metastasizing ameloblastoma can only be carried out in retrospect, after the event of metastasis. This case report describes a patient with metastatic pulmonary ameloblastoma, 17 years after the surgical excision of an odontogenic tumor, preoperatively misdiagnosed as primary squamous cell carcinoma.

Ameloblastoma with varied sites of metastasis: report of two cases and literature review

OBJECTIVE

We report two rare cases of lung metastasis from maxillary ameloblastoma, in order to review its risk and analyse the types of metastases that can present with this disease.

METHODS

A 40-year-old male with multiple recurrences and a 46-year-old female, who had undergone successful surgical treatment of a maxillary ameloblastoma, presented with metastatic lesions. The primary tumour and metastases were benign in both patients. We reviewed and analysed 20 cases of the same condition reported in recent years.

RESULTS

Our initial treatment for the primary maxillary lesion was performed more than 10 years before the pulmonary lesions presented. Due to the aggressive nature of this tumour, metastases in the lungs and cervical lymph nodes (male patient) were confirmed.

CONCLUSION

These cases presented a diagnostic challenge due to the multiple and varied sites of recurrence, which indicate the natural behaviour of this tumour. Different routes of metastasis can occur, including implanting, haematogenous, and lymphatic spread. CT-guided percutaneous transthoracic lung biopsy is an important method to confirm metastatic ameloblastoma.

Endoscopic transnasal resection of ameloblastoma with intracranial extension

Ameloblastoma is a rare odontogenic tumor with characteristics of epithelial tissue that produces enamel for the developing tooth. This lesion is generally considered benign, but has malignant forms that invade locally and metastasize. We present a 60-year-old man with maxillary ameloblastoma that after multiple recurrences developed intracranial extension with dural involvement of the middle cranial fossa and was treated by endoscopic transnasal resection followed by radiation therapy. Our technique and intraoperative findings are described with a review of the literature on intracranial ameloblastoma. This patient represents a unique account of endoscopic transnasal resection being utilized in the treatment of intracranial extension of ameloblastoma and demonstrates potential for application in similar cases.

Metastasizing Ameloblastoma With Localized Interstitial Spread in the Lung: Report of Two Cases

Ameloblastoma is a locally aggressive, epithelial odontogenic tumor involving mandibles and maxillas. Distant metastasis is a very rare condition and is designated as metastasizing (malignant) ameloblastoma despite its benign histological appearance. Up to now, only 27 well-documented cases of metastasizing ameloblastomas are reported in the literature, and lung is the most commonly involved organ. In previous reports of pulmonary metastasizing ameloblastomas, there was little description of the histopathologic finding. Here, the authors report 2 cases of pulmonary metastasizing ameloblastomas with special emphasis on their interesting, interstitial spread along alveolar septa, resulting in a unique 2-cell pattern under microscopic examination. Pulmonary metastasizing ameloblastoma may pose difficulty in diagnosis if the pathologist is not aware of patient's clinical history of ameloblastoma.

Malignant ameloblastoma: concurrent presentation of primary and distant disease and review of the literature

Malignant ameloblastoma is a rare tumor of odontogenic origin with a metastatic focus. Distant metastatic disease is found most commonly in the lungs. A review of the literature shows that most cases of malignant ameloblastoma involve a disease-free period from primary tumor extirpation to the discovery of metastasis. This report describes the case of a 56-year-old man presenting with ameloblastoma of the maxilla and a solitary pulmonary metastasis concurrently. This represents a rare case in which there is a simultaneous diagnosis of primary ameloblastoma and a metastatic lesion. Appropriate workup for ameloblastoma includes surveillance for metastatic disease. Surgical resection of primary and distant disease is recommended. Chemotherapy and radiation may play a role in palliation when resection of metastatic disease is not feasible.

Metastatic ameloblastoma responding to combination chemotherapy: case report and review of the literature

BACKGROUND

Ameloblastoma is a rare benign odontogenic tumor with locally aggressive behavior and a high recurrence rate. When metastases occur, which are uncommon, lungs constitute the most frequent site involved. Malignant ameloblastomas are different from ameloblastic carcinomas. Malignant ameloblastomas are tumors considered metastatic despite the appearance of well-differentiated or benign histology, while ameloblastic carcinomas are histologically malignant in both primary and metastatic sites.

CASE PRESENTATION

A 24-year-old Moroccan man presented a malignant ameloblastoma of the mandible. The tumor was entirely resected. Five years later, a local recurrence occurred. Our patient was treated by exclusive radiotherapy with persistence of a residual disease. After two years he developed multiple lung metastases. Our patient received a combination chemotherapy using doxorubicin and cisplatin.

CONCLUSION

Less than 50 cases of ameloblastoma with metastases have been reported. There is still no standard treatment for metastatic ameloblastoma. Only through continuous reporting of such cases will clinicians be able to draw an optimal strategy for management of this pathology.

Ameloblastoma of the mandible with pulmonary metastases 45 years after initial diagnosis

Ameloblastoma of the mandible is a rare odontogenic tumour that rarely metastasizes. We report a patient with a slowly progressing ameloblastoma of the mandible diagnosed at the age of seven and resected multiple times due to tumour recurrence. Multiple pulmonary metastatic nodules were resected at thoracotomy 27 years after the initial diagnosis; however, further pulmonary disease was discovered. The patient was admitted with chest pain due to pulmonary metastases 45 years after the initial diagnosis. The metastases were intraluminal and could be attributed to tumour cell aspiration during the surgical procedures on the mandible. The patient also suffered from hypercalcaemia which was attributed to a parathormone-like substance secreted by the tumour.

Métastases multiples d’un améloblastome mandibulaire

INTRODUCTION

Ameloblastoma is a benign odontogenic tumor which can be locally aggressive and invasive. Metastases are rare but possible and must be considered as a malignant form of the tumor.

OBSERVATION

A 50-year-old woman presented a jugal metastasis of a mandibular ameloblastom which had been treated several times 28 years earlier. Six months after resection of the metastasis, the patient developed multiple cervical node metastases which were removed by radical curettage. Five months later, new metastases developed on the scalp and three months later a voluminous metastasis involving the right hemiface extended to the base of the skull. Surgical resection was only partial followed by radiotherapy. Ten months later the outcome was favorable.

DISCUSSION

The absence of any histological sign of malignity in the primary tumor and in the metastases, as observed in our patient, is remarkable. Metastases generally develop in the lung (61-80% of cases). Metastases to the scalp have never been described. The time to development of a metastasis is generally very long and metastases usually remain asymptomatic. Progression is very slow, like for the primary tumor. Several factors predictive of metastasis have been described: female gender, age at onset of primary tumor (2nd to 3rd decade) and multiple local recurrences. There is no standard treatment for metastases. Chemotherapy is not effective. Radiotherapy may be effective, particularly when lesions are not accessible to surgery. Surgical resection remains the treatment of choice.

Malignant ameloblastoma metastatic to the lungs 29 years after primary resection: a case report

We describe a case of a 55-year-old man presenting with a metastatic malignant ameloblastoma 29 years after the primary tumor was resected. This represents the longest period between initial diagnosis and first subsequent metastasis recorded as a case report. This case illustrates distinctions between the terms metastatic and malignant; it also highlights the difficulties derived from the accumulation of data by new diagnostic modalities (electron beam CT and positron emission tomography) and their integration into assessment algorithms.

Pulmonary metastasis of ameloblastoma: case report and review of the literature

Ameloblastomas are benign tumors of odontogenic epithelial origin. There is a high incidence of local recurrence associated with these tumors, and distant metastasis is rare. A review of the English literature shows that there have been 41 prior reports of pulmonary metastases from ameloblastomas of the oral cavity. We present another case of ameloblastoma metastatic to the lung and review the histopathology and mechanism of metastatic spread.

Ameloblastic carcinoma of the mandible

BACKGROUND

Ameloblastic carcinoma is a rare, aggressive odontogenic neoplasm of the jaws in which the epithelial cells exhibit cytologic features of recognizable ameloblastoma and malignancy. Cases with metastasis have been infrequently reported.

METHODS

A case of a 64-year-old white woman with mandibular ameloblastic carcinoma with documented distant metastasis is presented. The patient's presenting symptoms included facial asymmetry of the right jaw over 2 months and the development of moderate trismus. Clinical manifestations, pathology, treatment, and biologic behavior are discussed. The nomenclature and classification of odontogenic carcinomas are reviewed, including entities that should be considered in the differential diagnosis.

RESULTS

The patient underwent surgical resection consisting of mandibulectomy, parotidectomy, and modified radical neck dissection followed by radiation to both necks and tumor bed. Postsurgically, the patient developed pulmonary metastasis at 11 months and expired with widespread metastatic disease at 28 months.

CONCLUSIONS

This case demonstrated an unusual behavior pattern in that local recurrence and regional metastasis did not occur. Distant metastasis occurred despite apparent adequate control of the primary mandibular tumor. The ameloblastic carcinoma is a highly malignant neoplasm which requires aggressive therapy. Prognosis is poor. Further reporting of ameloblastic carcinoma is encouraged.

Atypical ameloblastoma: report of 3 cases and a review of the literature

This paper presents 3 atypical ameloblastomas which had a fatal outcome. One had histological features indicative of malignancy but without metastasis, another developed pulmonary metastasis and the third died of extensive infiltration of the skull base. The features of malignant ameloblastoma are discussed and reported cases of malignant ameloblastoma between 1966 and 1993 are reviewed.

Pulmonary metastatic disease in ameloblastoma

Ameloblastoma is a rare disease of odontogenic origin with indeterminate metastatic potential. The first site of metastatic disease is usually the lung. We report aggressive surgical treatment of a patient with bilateral disease with five subsequent recurrences. A review of the literature suggests that in the absence of effective chemotherapy or radiation, surgery should be considered the treatment of choice for metastatic ameloblastoma confined to the lung.