Malignant ameloblastoma: classification, diagnostic, and therapeutic challenges

Use of 3D printed model as a reconstruction aid in the management of an extensive ameloblastoma of the mandible

Ameloblastoma is a benign jaw tumor that can grow to a very huge size with high rate of recurrence. The large tumors pose a challenge during resection and reconstructive surgery. We present a massive ameloblastoma of the mandible that was surgically treated with the aid of 3D printed model.

Metastatic mandibular ameloblastoma of the lung ten years after primary resection: A rare case report

Ameloblastoma is a rare odontogenic neoplasm of the jaw. It usually behaves as a benign, slow growing tumour of the oral cavity with a high recurrence rate, especially when it is inadequately resected. A small proportion of ameloblastomas metastasize to distant organs, with lungs representing the most common site of metastatic spread. In this report, we present the case of a middle-aged man with two pulmonary nodules and a history of mandibular ameloblastoma excised 10 years prior to this radiological finding. Following resection and histopathological analysis of the lung lesion, a diagnosis of metastatic ameloblastoma was confirmed. No local recurrence of the primary tumour was identified. At 1-year follow-up, the patient had no evidence of local or metastatic disease.

Ameloblastoma: clinical presentation, multidisciplinary management and outcome

We studied 21 patients who underwent radical ameloblastoma excision followed by immediate reconstruction. Comorbidities, consumption of alcohol and/or tobacco and BMI status did not contribute to an unfavorable outcome. Giant ameloblastoma (≥5 cm) and/or tumor involving bony curvatures increased surgical complexity, the incidence of complications and hospital stay.

Pulmonary resection for multiple lung metastasis from ameloblastoma: a rare case report and literature review

INTRODUCTION

Ameloblastoma is a benign odontogenic epithelial neoplasm. Lung metastasis of ameloblastoma is extremely rare, and its biological behavior is still largely unknown. There is no consensus regarding the best method to treat metastasizing ameloblastoma.

CASE PRESENTATION

This report documents a 37-year-old female patient with multiple incidental bilateral pulmonary nodules on computed tomography (CT) and a medical history of ameloblastoma of the left mandible. On admission, her physical examinations and laboratory examinations were unremarkable. The patient underwent partial lobectomy of the middle right and lower right lung nodules via video-assisted thoracoscopic surgery, and the pathological diagnosis was confirmed as 'metastasizing ameloblastoma.' No adjuvant therapy was administered, and no evidence of progression was observed at the 12-month follow-up.

CONCLUSION

This is a rare case with multiple lung metastasis from ameloblastoma who was successfully treated with multiple pulmonary resections. The present study indicated that surgery may be considered an appropriate choice for lung metastasis of ameloblastoma.

The dilemma of extensive unilocular radiolucent lesions of the jaws - value of immunohistochemistry as a diagnostic marker and prognostic Indicator

INTRODUCTION

Large Unilocular radiolucent lesions of the jaws often present a dilemma to both, the Oral Pathologist and the Maxillofacial surgeon with regards to their accurate diagnosis as well as their most appropriate treatment modality. A precise identification as to whether the lesion is a cyst or a tumor is imperative before any treatment is instituted. Once the correct diagnosis and likely prognosis are established, a management protocol can be planned which will completely eliminate the lesion, while at the same time, ensure least possible morbidity for the patient, such as pathological jaw fractures, persisting neurological deficits, esthetic deformity, functional debility, recurrence/persistence of the lesion, etc. AIM & OBJECTIVES: To establish the value of Immunohistochemistry (IH) as a Diagnostic marker and Prognostic indicator for extensive Unilocular radiolucent lesions of the jaws. To assess its role as an adjunct to Histopathological Examination (HPE) in distinguishing Odontogenic tumours from the cysts, by identifying the former using IH Tumor Markers; and in aiding in selection of the most appropriate and effective treatment option for each of such ambiguous lesions, based on their prognosis as indicated by the expression of lH Cell Proliferation Markers.

MATERIALS AND METHOD

Thirty cases of large Unilocular Radiolucent lesions of the jaws (Maxilla/Mandible) were managed over a period of three years. Histopathological examination (HPE) and Immunohistochemical (IH) analysis were carried out of the biopsy specimens in all the cases. Calretinin, an Immunohistochemical Tumor marker, was used to distinguish between Odontogenic cysts and tumours. Ki-67 and Proliferating Cell Nuclear Antigen (PCNA), Immunohistochemical Cell Proliferation markers, provided information on the aggressive potential of the lesions. On the basis of the above information, an appropriate management protocol was established for each of these different lesions. Nerve sparing enucleation and curettage was employed for the established cases of Odontogenic Cysts; Enucleation and curettage, peripheral ostectomy, followed by chemical cauterization was employed for the Unicystic Ameloblastomas and other Odontogenic tumours with a low Ki-67 and PCNA Proliferation Index (PI)/Labelling index (LI ≤ 3); Marginal resection was carried out for the tumours with a higher Labelling Index (LI >3 ≤5), and Segmental resection (including partial/complete Maxillectomy, Hemimandibulectomy with/without disarticulation) for the aggressive pathologies with high Labelling Index (LI > 5).

RESULTS

Of the thirty cases of large Unilocular radiolucent lesions of the Maxilla and Mandible, thirteen were diagnosed as Dentigerous cysts, one as Dentigerous cyst showing Ameloblastomatous transformation; two as Unicystic Ameloblastomas, one as the Mural variant of Unicystic Ameloblastoma; four as Follicular Ameloblastomas, two as Plexiform Ameloblastomas; four as Acanthomatous Ameloblastomas; one as Ameloblastic Fibroma and two as Adenomatoid Odontogenic Tumours. The predictive and prognostic indication of the Immunohistochemical markers correlated well with the post treatment findings.

CONCLUSION

In cases of extensive Unilocular lesions of the jaws, where ambiguity often exists in both diagnosis and appropriate treatment plan to be employed, Immunohistochemistry can serve as an invaluable tool in establishing the precise diagnosis, guiding the treatment plan, as well as indicating the likely prognosis of these lesions.

A historical case of an ameloblastoma, from southern Italy

Jawbones are susceptible to various tumours, some of which originate from dental structures. Here we describe a case of a tumour in a mandible of an old man that was discovered during an archaeological excavation in southern Italy (Torrecuso; 17th-19th centuries). The right mandibular branch presents an extended, multilocular lesion. X-ray analysis shows erosion of the cortical bone layers and the thin trabeculae that circumscribe the lobular areas. Macroscopic and radiological aspects of the mandibular lesion are consistent with an ameloblastoma. This diagnosis is supported by comparative morphological and radiological analyses of the sample from Torrecuso with modern cases. This is a common tumour type reported in the medical literature, which is characterised by a multilocular lesion usually at the branch of the mandible. However, cases of ameloblastoma are not common in archaeological and anthropological reviews. Cases of amleoblastoma were described for two adult female individuals discovered in South America (550-850 CE) and an adult male discovered in Spain (5th-11th centuries CE). The most ancient case comes from the Samnitic archaeological site of Opi (central Italy; 6th-5th centuries BCE). The present case is the second one diagnosed in ancient human remains from Italian archaeological contexts.

Magnetic resonance imaging of the maxilla and mandible: signal characteristics and features in the differential diagnosis of common lesions

The maxilla and mandible are among the most difficult areas of the body to image with magnetic resonance techniques owing to the geometry of the jaws as well as the frequent susceptibility artifacts from dental restorations or appliances. This chapter briefly reviews the essentials of imaging techniques and basic anatomy and discusses the most common inflammatory conditions, benign and malignant lesions of the jaws, and temporomandibular joint. This review emphasizes and illustrates specific magnetic resonance features that facilitate characterization and diagnostic differentiation of these lesions. As the focus of this review is on the differentiation of infection and benign and malignant disease, a discussion of internal derangements and associated inflammatory disorders of the temporomandibular joint is beyond the scope of this review and is not discussed.

Lesions of the Jaw

Imaging of lesions within the maxilla and mandible is often fraught with difficulty owing to the similarity in the imaging appearance of a diverse array of pathological processes. Principally, lesions arise from either odontogenic sources or from primary bone lesions. The response of the cancellous and cortical bone to pathologic insult can be expressed either through an osteolytic or an osteoblastic response; thus the majority of lesions within the jaws can be classified as cystic or lytic appearing, sclerotic, or a mixture of the two. This article will review the imaging features of the most common cysts, fibro-osseous lesions, benign and malignant neoplasms, and highlight those features key to the differential diagnosis.

Management Issues in the Treatment of an Ameloblastoma with an Atypical Presentation

Benign ameloblastoma (BA) is the most common tumor arising from the odontogenic epithelium. Surgical resection with adequate margins is the mainstay of treatment due to the high index of tumor recurrence when not completely excised. Although locoregional spread has been described in the literature, it is very uncommon. We describe the treatment and follow-up of a 22-year-old woman with multiple recurrences and locoregional spread of a mandibular ameloblastoma who was referred to our center after several tumor resections with subsequent reconstructions. After a complete macroscopical removal of a new recurrence, the mandible was primarily reconstructed. A local homolateral recurrence and a second lesion in the contralateral maxilla were detected after 1-year follow-up and accordingly treated. After 4 years the patient showed a new tumor in the temporal fossa and was reoperated. The histopathology was consistent with a BA in all cases. Even though it is rare, locoregional spread of BA has been reported previously. Recurrences discovered during follow-up may require further resections. A close follow-up is mandatory, and treatment of these cases may result demanding requiring a multiple team approach, including oncologists and radiotherapists.

Incidence and overall survival of malignant ameloblastoma

BACKGROUND

Malignant ameloblastoma, comprising metastasizing ameloblastoma and ameloblastic carcinoma, represents 1.6-2.2% of all odontogenic tumors. Due to its rare nature, malignant ameloblastoma has only been reported in the literature in small case series or case reports. Using the Surveillance, Epidemiology and End-Results (SEER) database, we have performed a population-based study to determine the incidence rate and the absolute survival of malignant ameloblastoma.

METHOD

Using the International Classification of Diseases for Oncology (ICD-O) codes 9310/3 and 9270/3, data from the SEER database were used to calculate the incidence rate and absolute survival rate of population with malignant ameloblastoma.

RESULTS

The overall incidence rate of malignant ameloblastoma was 1.79 per 10 million person/year. The incidence rate was higher in males than females and also higher in black versus white population. The median overall survival was 17.6 years from the time of diagnosis and increasing age was associated with a statistically significant poorer survival.

CONCLUSIONS

To our best knowledge, we report the largest population-based series of malignant ameloblastoma. The incidence rate was 1.79 per 10 million person/year and the overall survival was 17.6 years.

A single cervical lymph node metastasis of malignant ameloblastoma

INTRODUCTION

Cervical node metastasis of malignant ameloblastoma is extremely rare. Because of its rarity, there is no standard treatment modality in a single lymph node metastasis in malignant ameloblastoma.

MATERIALS AND METHODS

Eleven patients of malignant ameloblastoma involving a single cervical lymph node metastasis and one new case were reviewed. Neck treatment was classified into neck dissection and simple excision. Local nodal recurrence, distant metastasis and follow-up periods were investigated.

RESULTS

Eight patients were treated with neck dissection (group A) and four patients underwent a simple node excision (group B). Two patients in group A experienced multiple organ metastases such as liver and lung seven months and 13 years after neck dissection respectively. The other patients showed no recurrence and metastasis. In group B, there was no report of a regional neck recurrence and distant metastasis during follow-up of 1-7 years.

CONCLUSION

Multiple nodes metastasis requires a radical neck dissection; however, simple excision with close follow-up may be used in a single node metastasis in malignant 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.

Ameloblastic carcinoma: a case report with radiological features of computed tomography and magnetic resonance imaging and positron emission tomography

Ameloblastic carcinoma is a rare malignant odontogenic carcinoma that has metastatic potential, and because of its rare incidence, there are few reports focusing on its radiologic imaging. If it shows aggressive appearances, it can be diagnosed as malignant tumor. But in case of negative appearance, it is difficult to distinguish ameloblastic carcinoma from ameloblastoma. We report a case of ameloblastic carcinoma of the maxilla in a 76-year-old female patient with radiologic images and pathologic features.

Ultrasonographic evaluation of mandibular ameloblastoma: a preliminary observation

OBJECTIVE

The purpose of this study was to demonstrate ultrasonographic characteristics of mandibular ameloblastoma and assess the value of ultrasonography in diagnosis of the tumor.

STUDY DESIGN

Nineteen subjects with ameloblastomas in the mandibles were examined with ultrasonography. Locations, sizes, internal echoes, boundaries, and blood flow of the tumors were observed and documented. Ultrasonographic appearances of the tumors were compared with histopathological findings. Sensitivity and specificity of Doppler flow signals for prediction of active tumor proliferations were calculated.

RESULTS

The main sonographic features of the tumor appeared as a complex cystic mass with solid contents. Most tumors (15/19, 79%) showed no or minimal flow signals on color Doppler flow imaging (CDFI), whereas the remaining 4 lesions demonstrated abundant flow signals. The sensitivity and specificity of the Doppler flow signals for prediction of active tumor proliferations were 100% and 94%, respectively. The ultrasonographic appearances could be classified into 4 types: multilocular (10/19, 53%), honeycomb (4/19, 21%), unilocular (3/19, 16%), and local severe destructive (2/19, 10%).

CONCLUSION

Ultrasonography can be used as an effective supplementary diagnostic method for mandibular ameloblastomas. CDFI of tumor vascularity could be used to predict active tumor proliferations.

Malignant ameloblastoma metastasis to the lung: a case report

Ameloblastoma is an odontogenic tumor, usually benign, which rarely metastasizes to distant organs. The case of a 27-year-old white woman is described, who presented a metastatic pulmonary ameloblastoma 7 years after the removal of a mandibular ameloblastoma. She presented no pulmonary symptoms, but a lung nodule was found in a chest x-ray during a routine check-up for job admission. Computed tomography (CT) revealed a 2-cm well-defined solitary round nodule without calcifications, leading to the hypothesis of a metastatic tumor. Clinical and CT investigation confirmed no ameloblastoma recurrence in the jaw and no other primary tumor. The diagnosis of metastatic ameloblastoma was confirmed by microscopic evaluation of the pulmonary nodule.

Immediate Mandibular Reconstruction With Microsurgical Fibula Flap Transfer Following Wide Resection for Ameloblastoma

Ameloblastoma, the most common odontogenic tumor, is a slow growing, localized tumor of the facial skeleton. Eighty percent of the tumors affect the mandible. Treatment by wide excision is curative in 95% of cases. Reconstruction by bone grafting has a 20% to 30% nonunion rate. We have treated three large ameloblastomae (>6 cm) with fibula flaps, following resection. All patients have healed. With follow-up times of 2 to 3 years, there has been no evidence of recurrence and no difficulties with postoperative evaluation for recurrent disease. We conclude that the fibula flap is a reliable reconstructive operation following resection of large ameloblastomae.

Malignant tumors of the mandible and maxilla

Malignant tumors of the mandible and maxilla are grouped into primary tumors that originate within the mandible and secondary lesions, predominantly oral cancers and metastatic lesions, that involve the mandible secondarily. The most common malignant tumors of the mandible represent SCCs of the oral cavity, notably carcinoma of the floor of the mouth and gingiva that invade the mandible secondarily. Metastatic disease, most commonly from the breast and lung, are not an uncommon malignant lesion in the mandible and may be the first manifestation of a malignant lesion outside the head and neck. The osteogenic sarcoma is the most common sarcomatous lesion in the mandible and is suggested when a bone-forming matrix with sclerosis is found within the tumor on CT images. Some benign lesions may mimic a malignant tumor on imaging studies. In such cases, a biopsy is indicated to establish the diagnosis by histopathologic means. CT is indicated for assessment of bone destruction in the mandible before surgery or radiation therapy. MR imaging is the optimal modality for the assessment of marrow involvement and evaluation of the extraosseous soft tissue component. Finally, conventional films, frequently a Panorex view, are the initial radiographic examinations in suspected lesions.