Ameloblastic carcinoma of the maxilla

doi:10.1016/S1368-8375(03)00036-8

Oral Oncology

Volume 39, Issue 7, October 2003, Pages 736-741

https://doi.org/10.1016/S1368-8375(03)00036-8 Get rights and content

Abstract

The maxilla is an unusual site for an ameloblastoma, and certainly for an ameloblastic carcinoma. Ameloblastomas are considered as benign, yet locally aggressive neoplasms in the vast majority of cases. However, very rarely, these tumors demonstrate a clinical course of malignancy. Recently, a classification system was published differentiating between malignant odontogenic carcinoma variants. The two such forms include malignant ameloblastoma, and ameloblastic carcinoma. In the differential diagnosis, the designation of malignant ameloblastoma is reserved for lesions that, despite their benign histology, metastasize as well-differentiated cells. The diagnosis of ameloblastic carcinoma is reserved for tumors that demonstrate a malignant morphologic appearance, regardless of whether metastasis is a proven fact at the time of discovery and treatment. We discuss the presentation, pathology, and treatment of the 18th case of a maxillary ameloblastic carcinoma in the literature.

Introduction

Ameloblastomas are rare tumors of odontogenic origin, yet within the group of odontogenic carcinomas, they represent the second most common tumor following the odontoma. Current thinking believes that these tumors arise from derivatives of the epithelial component of the developing tooth that has arrested development before the induction of enamel, or other formed element. There are five clinical/radiographic sub-types of ameloblastoma that include the unicystic variant, the multi-cystic variant, the desmoplastic variant, the peripheral variant, the malignant ameloblastoma, and several histologic variants including plexiform, follicular, granular cell, acanthomatous and basaloid forms.

The term “malignant ameloblastoma” has been a subject of discussion for many years. Ameloblastomas behave as benign, but locally aggressive neoplasms, however, very rarely do they demonstrate a clinical course characteristic of malignancy. In 1972, the WHO included the malignant ameloblastoma with odontogenic carcinomas.¹ According to the definition, this neoplasm demonstrates features of ameloblastoma both in the primary lesion and in any metastatic growth. Therefore, ameloblastomas were classified as malignant only retrospectively, once the tumor demonstrated a clinical course of malignancy.

A second conflict in the classification of ameloblastomas occurred when rare variants of this type of tumor demonstrated overt cytological malignancy. Subsequently, Elzay further subclassified metastatic ameloblastomas under the heading of primary intraosseous carcinomas.² Metastatic ameloblastomas that retained a well-differentiated appearance were named malignant ameloblastomas, and those tumors that demonstrated a poorly differentiated appearance were considered ameloblastic carcinomas.

Finally, in 1984, Slootweg and Muller³ published the current classification system (Table 1) that categorized malignant ameloblastomas as tumors that, despite their cytologically benign appearance, metastasize as well-differentiated lesions. Furthermore, ameloblastic carcinomas were classified as tumors that combined morphologic features of ameloblastoma and carcinoma, regardless of the presence or absence of metastasis. Stressed was the importance of careful histologic evaluation in subclassifying this group of lesions.

We present the 18th case of maxillary ameloblastic carcinoma. Of note, this particular case was previously considered to represent a more typical or benign ameloblastoma.

Section snippets

Case management

A 72-year-old Caucasian male presented to us for a second opinion regarding a previously established diagnosis of a right maxillary tumor. The patient noted that he was in his usual state of health and was being evaluated for vertigo when a right maxillary sinus tumor was discovered incidentally on MRI. He had a history of dental problems, particularly in the region of the right maxillary molar. Soft tissue from this area was subsequently evaluated and biopsied with a preliminary diagnosis of

Discussion

Ameloblastomas represent only about 1% of tumors and cysts in the jaw.⁴ The maxilla is an unusual site for an ameloblastoma and certainly for an ameloblastic carcinoma, given the dearth of previously reported cases. Approximately 80% of ameloblastomas are located in the mandible, and 20% are found in the maxilla.⁴ In the differential diagnosis, the designation of malignant ameloblastoma is reserved for lesions that, despite their benign histology, metastasize as well-differentiated cells. The

References (20)

R.P Elzay
Primary intraosseous carcinoma of the jawreview and update of odontogenic carcinomas
Oral Surg Oral Med Oral Pathol.
(1982)
P.J Slootweg et al.
Malignant ameloblastoma or ameloblastic carcinoma
Oral Surg Oral Med Oral Pathol.
(1984)
I.A Small et al.
Ameloblastoma of the jaws
Oral Surg
(1955)
E Andersen et al.
Ameloblastic carcinoma of the maxilla
J Maxillofacial Surgery
(1986)
R.L Corio et al.
Ameloblastic carcinomaa clinicopathologic study and assessment of eight cases
Oral Surg Oral Med Oral Pathol.
(1987)
L Lee et al.
Ameloblastic carcinoma of the maxilla metastatic to the mandiblecase report
J Craniomaxillofac Surg
(1990)
P Infante-Cossio et al.
Ameloblastic carcinoma of the maxillareport of 3 cases
J Cranio Maxillofac Surg
(1998)
J Sastre et al.
Ameloblastic carcinoma of the maxillaa report of a case
J Oral Maxillofac Surg
(2002)
D.G Gardner
Some current concepts on the pathology of ameloblastomas
Oral Surg Oral Med Oral Pathol.
(1996)
Pindborg JJ, Kramer IRH, Torloni H. Histological typing of odontogenic tumors, jaw cysts and allied lesions. In:...

There are more references available in the full text version of this article.

Cited by (63)

Histopathological patterns and biological characteristics of ameloblastoma: A retrospective cross-sectional study
2022, Journal of Taibah University Medical Sciences
Citation Excerpt :
Biologically, ameloblastomas have also been found to transform into malignant entities (i.e. ameloblastic carcinoma and metastatic ameloblastoma) at a prevalence rate of only 2%.3 Metastatic ameloblastoma typically demonstrates well-differentiated benign histology, similar to the conventional type of ameloblastoma at the primary site, but additional foci of the benign histology are identified in location(s) remote from the primary and are considered to be a metastasis.17 This study aims to study the histopathological patterns and biological behaviour or characteristics of ameloblastoma in a cohort of Ugandan patients diagnosed between 2016 and 2019 at the department of pathology of Makerere University College of Health Science (MakCHS).
This study aims to determine the histopathological patterns and biological characteristics of ameloblastoma.
This was a cross-sectional retrospective laboratory-based study using 82 formalin-fixed paraffin-embedded tissue blocks from patients diagnosed histologically with ameloblastoma. Information regarding age, sex, anatomical location of the lesion, histopathologic type, and biological behaviour or characteristics of the types of ameloblastoma was obtained from laboratory request forms. Categorical and continuous variables were summarized in percentage and mean ± standard deviation, respectively. The cohort was conducted on Ugandan patients diagnosed between 2016 and 2019.
Most patients (66.3%) were clinically presenting a painless jaw swelling, and a follicular pattern was common (39%) followed by the plexiform pattern (12.2%). All the ameloblastoma cases (100%) were benign, with the majority (76.8%) cases being non-recurrent while the remaining (23.2%) were recurrent, and the plexiform pattern was the commonest recurrent histopathological pattern.
This study reports a relatively significant rate of recurrence in almost a quarter of the study population. The plexiform histopathologic type was the dominant type in recurrence cases. Therefore, this finding provides insightful information to clinicians to ensure close follow-up for patients diagnosed with such a variant to prevent possible relapse of the disease.
Odontogenic Cysts and Tumors
2020, Gnepp's Diagnostic Surgical Pathology of the Head and Neck, Third Edition
Odontogenic cysts and tumors represent a surprisingly diverse group of lesions of the jaws and overlying soft tissues. In general, odontogenic cysts may be developmental or inflammatory in origin. Developmental odontogenic cysts include the following: the dentigerous cyst, eruption cyst, odontogenic keratocyst, orthokeratinized odontogenic cyst, gingival cyst of the newborn, gingival cyst of the adult, lateral periodontal cyst, glandular odontogenic cyst, and calcifying odontogenic cyst. Inflammatory odontogenic cysts include periapical cysts and residual periapical cysts. In general, odontogenic cysts are benign, although malignant transformation is possible. Benign odontogenic tumors may be subclassified as follows: (1) epithelial (including ameloblastoma, calcifying epithelial odontogenic tumor, squamous odontogenic tumor, and adenomatoid odontogenic tumor); (2) mixed epithelial and mesenchymal (including ameloblastic fibroma, ameloblastic fibroodontoma, odontoma, primordial odontogenic tumor, odontoameloblastoma, and dentinogenic ghost cell tumor); and (3) mesenchymal (including central odontogenic fibroma, peripheral odontogenic fibroma, granular cell odontogenic tumor, and odontogenic myxoma). Furthermore, there are several types of malignant odontogenic tumors, including metastasizing ameloblastoma, ameloblastic carcinoma, primary intraosseous squamous cell carcinoma, clear cell odontogenic carcinoma, ghost cell odontogenic carcinoma, intraosseous mucoepidermoid carcinoma, ameloblastic fibrosarcoma, and odontogenic carcinosarcoma. The diversity of odontogenic cysts and tumors can be difficult to understand without basic knowledge of the process of odontogenesis. Hence, we begin with a review of the histology and embryology of tooth formation. In addition, clinical correlation is often essential for accurate diagnosis. Therefore we discuss the clinical features, as well as pathologic features, differential diagnosis, treatment, and prognosis for each entity.
Proton Beam Therapy for Ameloblastic Carcinoma of the Maxilla: Report of a Rare Case
2019, Journal of Oral and Maxillofacial Surgery
Citation Excerpt :
AC presents different clinical features in the maxilla and mandible and has a lower incidence in the maxilla than in the mandible.8 Maxillary AC lesions appear to occur slightly later in life (average age, 56.7 years) than mandibular AC lesions.9 Although AC lesions tend toward aggressive local growth and local relapse, distant metastases are uncommon.10
Ameloblastic carcinoma (AC) is a rare malignant odontogenic tumor that combines the histologic features of ameloblastoma with those of cytologic atypia. The standard treatment for this lesion is wide local excision. Proton beam therapy (PBT) can deliver high irradiation doses to the target and avoid irradiation to surrounding normal tissues, but no reports of PBT for AC have been published thus far. This report describes the case of a 70-year-old woman with a pathologic diagnosis of maxillary AC who refused surgical resection and received hypofractionated PBT at a total dose of 69 Gy in 23 fractions. She has been alive for more than 5 years after PBT without any evidence of recurrence and side effects. This is the first reported case of successful treatment after curative radiation therapy for maxillary AC.
Reconnoitre ameloblastic carcinoma: A prognostic update
2018, Oral Oncology
Malignant odontogenic tumor, ameloblastic carcinoma (AC) is challenging to study owing to its rarity, complexity and limited availability of literature. This further makes it difficult to establish its clinical characteristics and prognosis. Our study aimed to evaluate AC’s clinico-demographic factors and their relation with prognosis and survival.
Literature was systematically reviewed for cases pertaining to AC, starting from January 2000 to December 2016. All the required data was obtained, arranged and analysed using Cox regression ratio and Kaplan Meir survival analysis. From the database, 153 cases were retrieved as per the inclusion/exclusion criteria.
The results demonstrated that age of patient, mode of treatment and metastasis affects overall survival. The categorisation of AC as primary or secondary type does not have any role in determining prognosis.
Overall survival of AC patient depends upon age, site, treatment and metastasis. For a better prognosis early surgical management of the tumor appears to be the most favourable mode of treatment.
Single-Fraction Helical Tomotherapy for Ameloblastic Carcinoma
2016, Journal of Oral and Maxillofacial Surgery
Odontogenic tumours
2015, Diagnostic Histopathology
Odontogenic tumours are rare lesions and many non-specialist histopathologists will not have seen many during their working lifetime. The purpose of this review is to give an overview of odontogenic tumours, with an emphasis on differential diagnoses and common diagnostic pitfalls, especially for the more common tumours. It is not an exhaustive review but is intended to complement specialist texts, focussing on helpful features which pathologists may employ to increase confidence when reporting odontogenic tumours.

View all citing articles on Scopus

View full text

CASE REPORTAmeloblastic carcinoma of the maxilla

Abstract

Introduction

Section snippets

Case management

Discussion

Oral Surg Oral Med Oral Pathol.

Oral Surg Oral Med Oral Pathol.

Oral Surg

J Maxillofacial Surgery

Oral Surg Oral Med Oral Pathol.

J Craniomaxillofac Surg

J Cranio Maxillofac Surg

J Oral Maxillofac Surg

Oral Surg Oral Med Oral Pathol.

CASE REPORT
Ameloblastic carcinoma of the maxilla