Histopathological features revealed both follicular as well as plexiform ameloblastoma which adds to the unique case till reported in literature. The ua, first described by robinson and martinez in 1977, is relatively a rare type of ameloblastoma accounting for about 1015 % of all ameloblastomas. The author presents two case reports of recurrent ameloblastomas postradical resection. Jun 25, 2019 ameloblastoma is a rare, benign or cancerous tumor of odontogenic epithelium much more commonly appearing in the lower. In this pattern, the ameloblastoma follicular pattern seems to be turned inside outthat is, the preamelblasts are now surrounded by the stellate reticulum, and the latter cells surround the collagen stroma fig. Plexiform ameloblastoma europe pmc article europe pmc. Follicular ameloblastoma or plexiform ameloblastoma. The choice of treatment depends on the histologic subtype. It is locally aggressive with unlimited growth capacity and has a high potential for malignant transformation as well as metastasis. A plexiform histologic pattern of ameloblastoma with back. Microscopically, ameloblastoma is composed of epithelial islands in collagen connective tissue stroma. Although the diagnosis of acanthomatous ameloblastoma is based on. The unicystic ameloblastoma represents an ameloblastoma variant that on gross examination, and not based on the appearance on the radiograph, presents as a cyst. Clinical and radiologic behaviour of ameloblastoma in 4 cases.
It exhibits several distinctive clinicopathologic features that separate it from conventional ameloblastoma, including a predilection for relatively young individuals, typically unilocular radiographic appearance, macroscopically cystic architecture, and often favorable response to conservative treatment. Plexiform ameloblastoma with anastomosing strands and cords of tumour cells hkstopathology. Follicular with plexiform ameloblastoma in anterior. Radical therapy is the recommended modality for solid ameloblastomas. In the present study, a case of unusually large plexiform ameloblastoma was presented with its clinical, radiological, histological features and treatment modalities, and this is the addition of one more case in the literature. The plexiform pattern is thought to occur more frequently in maxillary ameloblastomas. Ameloblastoma has no established preventive measures although majority of patients are between ages 30 and 60 years. Ameloblastoma appears most commonly in the third to. Unicystic ameloblastoma is an uncommon variant of ameloblastoma. Pdf ameloblastoma is a benign locally invasive epithelial odontogenic tumour comprising 1% of all tumours and cysts arising in the jaws. The relative frequency of unicystic ameloblastoma has been reported as 5% and 22%.
The follicular type will have outer arrangement of columnar or palisaded ameloblast like cells and inner zone of triangular shaped cells resembling stellate reticulum in bell stage. Ameloblastoma is a benign, locally aggressive neoplasm believed to arise from odontogenic epithelium, including remnants of the enamel organ reduced enamel epithelium found overlying the crown of an unerupted tooth, remnants of hertwigs epithelial root sheath rests of malassez found throughout the periodontal ligament, or epithelial remnants of the dental lamina. Ameloblastoma is a benign tumor of odontogenic epithelium which is more commonly seen in the posterior region of mandible and the maxilla. Using the regeze, kerr and courtney classification 1978, we diagnosed follicular tumor in 11 cases, plexiform in 6 cases and unicystic in 3 cases, and performed surgical resection with a safety margin of 1. The histopathological processing of the tumor revealed. Histopathology of ameloblastoma of the jaws med oral patol oral. This type of odontogenic neoplasm was designated as an adamantinoma in 1885 by the french physician louischarles malassez. Pdf ameloblastoma is a true neoplasm of enamel organ type tissue which does not undergo differentiation to the point of enamel formation.
There are layers of cells in between the proliferating epithelium with a wellformed desmosomal junctions, simulating spindle cell layers. Murali 3 saramma mathew 4 james chacko5 george paul6 1senior lecturer 2reader 3professor and head, 4ex professor emeritus, department of oral. Mar 06, 2020 webpathology is a free educational resource with 10197 high quality pathology images of benign and malignant neoplasms and related entities. Its made from cells that form the enamel that protects your teeth the tumor can cause pain. Ameloblastoma is a rare, benign or cancerous tumor of odontogenic epithelium ameloblasts, or outside portion, of the teeth during development much more commonly appearing in the lower jaw than the upper jaw. The peripheral ameloblastoma is the soft tissue version of the central intraosseous ameloblastoma. Jun 25, 2005 unicystic ameloblastoma presenting in gardners syndrome. Incisional biopsy was done under local anesthesia and sent for histopathological examination. Ameloblastoma is a benign locally invasive epithelial odontogenic tumour comprising 1% of all tumours and cysts arising in the jaws. Pdf ameloblastoma, a benign epithelial odontogenic tumor, is locally aggressive. Introduction ameloblastoma is a locally destructive tumor with a propensity for recurrence if not entirely excised. We present an extensive case of plexiform ameloblastoma of the mandible in a 42yearold female patient.
Hybrid desmoplastic ameloblastoma da composed of typical desmoplastic ameloblastoma along with areas of follicularplexiform ameloblastoma is an extremely rare variant of ameloblastoma. A 15yearold male patient reported with the chief complaint of swelling on the left side of lower jaw since 910 months. Histopathology reported a plexiform ameloblastoma, which appeared to arise in a dentigerous cyst. Jan 17, 2017 there are six different patterns of manifestation for ameloblastoma under the microscope. Ten ex amples of cystic jaw lesions that manifested an apparently distinctive altered epithelium were analyzed and were compared with published photomicrographs of early ameloblastomas, mural ameloblastoma, and. In limited sample, may not be distinguishable from unicystic ameloblastoma macrocystic degeneration of conventional ameloblastoma limited biopsy sample requires inclusion of this entity in differential diagnosis basal palisading, with reverse polarity, hyperchromatic basal layer stellate reticulumlike layer. Ameloblastoma histopathology will show cells that have the tendency to move the nucleus away from the basement membrane. Odontogenic tumours, ameloblastoma, histopathology. The excised mass was sent for histopathology examination, which further. The ameloblastoma also has a few variations in histopathological appearance, but the most common types are follicular and plexiform. Mandible, unicystic ameloblastoma, plexiform ameloblastoma, odontogenic tumour 1. The tumor epithelium is arranged in form of networktabeculae which is bound by a layer of cuboidal or columnar cells and stellate reticulum like areas are usually minimal. It is commonly found in the third and fourth decade in the molar ramus region of the mandible. Ameloblastoma russian federation pdf ppt case reports.
The tumor was found to be extending from mandibular body up to ramus, coronoid process, and condyle. The patient underwent a surgical procedure for oen bloco resection of the lesion with complete removal of the tumor and safety margins of approximately 15 mm, which were tumorfree. Unicystic ameloblastoma presenting in gardners syndrome. Odontogenic tumours are rare lesions and many nonspecialist histopathologists will not have seen many during their working lifetime.
As it shares common radiographic features with other lesions such as the giant cell tumor, aneurismal bone cyst, and renal cell carcinoma metastasis, a definitive diagnosis can only be made with histopathology. Ameloblastoma ab is the second most common benign epithelial odontogenic tumor. Histopathologic features and management of ameloblastoma. The term plexiform refers to the appearance of anatomizing islands of odontogenic epithelium in contrast to a follicular pattern. This process is referred to as reverse polarization. Cystic type basal cell type acanthomatous type dysmoplasatic type 15. Out of these types, conventional ameloblastoma is the most common, representing 85% of all ameloblastomas, and occurs mainly in the 3rd and 4th decades of life. We report a case of plexiform unicystic ameloblastoma of mandible in a 15yearold male. Unicystic ameloblastoma, plexiform, intraluminal, tumor introducton ameloblastoma is a true neoplasm of odontogenic epithelium 1. We wish to share this case with the oral and maxillofacial fraternity and standardise the histopathology to aid in diagnosing these. The stroma is usually delicate, often with cystlike degeneration.
We present an uncommon variant of this entity, namely, unicystic ameloblastoma ua and describe its histopathological features as a fullblown lesion, such as its follicular, plexiform and mural forms. Ameloblastomas surgical and experimental pathology. B the columnar peripheral cells with reverse polarity of their nuclei is the most common and recognizable histologic feature of ameloblastoma. The possibilities of recurrence even after enbloc resection are still high. Benign peripheral nerve sheath tumor that surrounds multiple nerve fascicles has irregularly thickened, distorted, tortuous structure plexiform. Ameloblastoma is an odontogenic tumor arising from the epithelial rests of malassez, occurring mostly in the mandible and the tumor arises from the epithelium that plays a role in the process of tooth development. Pdf plexiform ameloblastoma of the mandible researchgate. Webpathology is a free educational resource with 10197 high quality pathology images of benign and malignant neoplasms and related entities. Each of these strands is bound by a layer of tall columnar cells, between these layers may be found stellate reticulum like cells, these stellate reticulum like tissue is less prominent in. Ameloblastoma is a benign odontogenic tumor of epithelial origin.
The term, plexiform ua, refers to a pattern of one or more nodules of ameloblasts like cells projecting from the cystic lining into the lumen of the cyst. About 66% of ameloblastomas occur in mandible most often in the molar ascending ramus area, while only 10% is seen in mandibular anterior area. Among all types of ameloblastoma, multicystic ameloblastoma is believed to be locally aggressive lesion that has the tendency for recurrence. A 15yearold male patient reported with the chief complaint of swelling on the left side of. There are layers of cells in between the proliferating epithelium with wellformed desmosomal junctions, simulating spindle cell layers. Ameloblastoma is a rare, benign or cancerous tumor of odontogenic epithelium much more commonly appearing in the lower. The plexiform type contains basal cells arranged in anastomosing strands with an inconspicuous stellate reticulum. Dec 06, 2011 the plexiform type contains basal cells arranged in anastomosing strands with an inconspicuous stellate reticulum. In most cases, an ameloblastoma is usually asymptomatic, grows slowly, and can expand jaws. Ameloblastoma histopathology pdf ameloblastoma is a rare, benign or cancerous tumor of odontogenic epithelium much more commonly appearing in the lower. Unicystic plexiform ameloblastoma with mural proliferation. Therefore the treatment of choice is surgical excision with wide free margins. Plexiform ameloblastoma does not have prominent palisading. In most cases, an ameloblastoma is usually asymptomatic, grows slowly, and can.
Primary ameloblastoma of the sinonasal tract schafer. There are six different patterns of manifestation for ameloblastoma under the microscope. Pdf ameloblastoma is a common and aggressive odontogenic epithelial. Ameloblastoma has no established preventive measures although majority of patients are. Jan 08, 2015 histopathological findings ameloblastoma can be classified into.
Ameloblastoma was known for its high recurrence rate if excision was incomplete. Cyst formation occurs but is usually due to stromal degeneration rather than cystic change in the epithelium. Plexiform unicystic ameloblastoma is a relatively rare variant of unicystic ameloblastoma. We wish to share this case with the oral and maxillofacial fraternity and standardise the. Here we present a case of plexiform ameloblastoma in. Different variants of unicystic ameloblastoma a report of. Apr 05, 2020 ameloblastoma is a rare, benign or cancerous tumor of odontogenic epithelium much more commonly appearing in the lower. Plexiform ameloblastoma with anastomosing strands and. The tumor found in our patient was an ameloblastoma of the plexiform type.
A marked geographic variation is apparent in the relative incidences of various odontogenic tumors. Follicular with plexiform ameloblastoma in anterior mandible. Journal of clinical imaging science plexiform ameloblastoma. The plexiform type has epithelium that proliferates in a fish net pattern. Mandible, plexiform ameloblastoma, odontogenic tumor. Ameloblastoma, neoplasms, odontogenic tumors, oral pathology. Correlating the histopathological and clinicoradiological features avoids a diagnostic pitfall show all authors andrew w. Ten ex amples of cystic jaw lesions that manifested an apparently distinctive altered epithelium were analyzed and were compared with published photomicrographs of early ameloblastomas, mural ameloblastoma, and examples of ameloblastoma. Histopathology of ameloblastoma e78 material and methods in the period between september 1970 and september 2010, 44 cases of a benign ameloblastoma and one case of a malignant ameloblastoma were encountered in the files of the department of oral and maxillofacial sur. This study used ki67 to evaluate the proliferative activity of ameloblastoma in an attempt to provide a scientific basis for any differences in the biologic behaviour that exists between the different types of ameloblastoma and correlate the results with the recurrence rate.
The ameloblast like cells are arranged in irregular masses, or more frequently, as a network of interconnected strands of cells. Using the regeze, kerr and courtney classification 1978, we diagnosed follicular tumor in 11 cases, plexiform in 6 cases and unicystic in 3 cases, and performed. Ameloblastoma symptoms, histology, radiology and diagnosis, surgery, treatment. Management of ameloblastoma poses a challenge for all involved in the field of head and neck surgery because successful treatment requires not only adequate resection but also a functional and aesthetically acceptable reconstruction of the residual defect. Molecular etiopathogenesis of ameloblastoma current. The plexiform ameloblastoma shows epithelium proliferating in a cord like fashion, hence the name plexiform. We assessed ki67 expression by immunohistochemistry in 32 cases of mandibular ameloblastoma. Here we are presenting a case of unicystic ameloblastoma in a 23 year old male patient. Ameloblastoma is locally aggressive benign odontogenic tumour with increased risk of recurrence rate. Dec 24, 2011 as it shares common radiographic features with other lesions such as the giant cell tumor, aneurismal bone cyst, and renal cell carcinoma metastasis, a definitive diagnosis can only be made with histopathology. Several histologic types of ameloblastoma are described in the literature including plexiform, follicular, basal cell, granular cell, clear cell, and acanthomatous. They are, the follicular pattern, plexiform pattern, acanthomatous pattern, ganular cell pattern. Ameloblastoma is a rare kind of tumor that starts in your jaw, often near your wisdom teeth or molars.
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