Oral Tumors
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The AVDC Nomenclature Committee is working with human oral pathologists, veterinary pathologists and veterinary oncologists to develop a set of names for specific tumor types that will be acceptable for standard use in veterinary dental patients.
The term “epulis” (plural = “epulides”) is a general term referring to a gingival mass lesion of any type. Examples of epulides include: focal fibrous hyperplasia, peripheral odotogenic fibroma, acanthomatous ameloblastoma, non-odontogenic tumors, pyogenic granulomas and reactive exostosis.
Types of Neoplasms Occurring in Oral Tissues (listed in alphabetical order)
Acanthomatous ameloblastoma (OM/AA):
A typically benign, but aggressive, histological variant of a group of epithelial odontogenic tumors known collectively as ameloblastomas which have a basic structure resembling the enamel organ (suggesting derivation from ameloblasts); the acanthomatous histological designation refers to the central cells within nests of odontogenic epithelium that are squamous and may be keratinized rather than stellate
Adenoma (OM/AD) :
Benign epithelial tumor in which the cells form recognizable glandular structures or in which the cells are derived from glandular epithelium
Adenocarcinoma (OM/ADC):
An invasive, malignant epithelial neoplasm derived from glandular tissue of either the oral cavity, nasal cavity or salivary tissue (major or accessory)
Amyloid producing odontogenic tumor (OM/APO):
A benign epithelial odontogenic tumor characterized by the presence of odontogenic epithelium and extra-cellular amyloid
Anaplastic neoplasm (OM/APN):
A malignant neoplasm whose cells are generally undifferentiated and pleomorphic (displaying variability in size, shape and pattern of cells and/or their nuclei)
Cementoma (OM/CE):
A benign odontogenic neoplasm of mesenchymal origin, consisting of cementum-like tissue deposited by cells resembling cementoblasts Biopsy
Feline inductive odontogenic tumor (OM/FIO):
A benign tumor unique to adolescent and young adult cats that originates multifocally within the supporting connective tissue as characteristic, spherical condensations of fibroblastic connective tissue associated with islands of odontogenic epithelium; has also been incorrectly called inductive fibroameloblastoma
Fibrosarcoma (OM/FS):
An invasive, malignant mesenchymal neoplasm of fibroblasts; a distinct histologically low-grade, biologically high-grade variant is often found in the oral cavity
Giant cell granuloma (OM/GCG):
A benign, tumor-like growth consisting of multi-nucleated giant cells within a background stroma on the gingiva (peripheral giant cell granuloma) or within bone (central giant cell granuloma); also called giant cell epulis
Granular cell tumor (OM/GCT):
A benign tumor of the skin or mucosa with uncertain histogenesis, most commonly occurring on the tongue; also called myoblastoma
Hemangiosarcoma (OM/HS):
A malignant neoplasm of vascular endothelial origin characterized by extensive metastasis; it has been reported in the gingiva, tongue and hard palate
Lipoma (OM/LI):
A benign mesenchymal neoplasm of lipocytes
Lymphosarcoma (OM/LS):
A malignant neoplasm defined by a proliferation of lymphocytes within solid organs such as the lymph nodes, tonsils, bone marrow, liver and spleen; the disease also may occur in the eye, skin, nasal cavity, oral cavity and gastrointestinal tract; also known as lymphoma
Malignant melanoma (OM/MM):
An invasive, malignant neoplasm of melanocytes or melanocyte precursors that may or may not be pigmented (amelanotic); also called melanosarcoma
Mast cell tumor (OM/MCT):
A local aggregation of mast cells forming a nodular tumor, having the potential to become malignant; also called mastocytoma
Multilobular tumor of bone (OM/MTB):
A potentially malignant and locally invasive neoplasm of bone that more commonly affects the mandible, hard palate and flat bones of the cranium with a multilobular histological pattern of bony or cartilaginous matrix surrounded by a thin layer of spindle cells that gives it a near pathognomonic radiographic “popcorn ball” appearance; also called multilobular osteochondrosarcoma, multilobular osteoma, multilobular chondroma, chondroma rodens, and multilobular osteosarcoma
Osteoma (OM/OO):
A benign neoplasm of bone consisting of mature, compact, or cancellous bone
Osteosarcoma (OM/OS):
A locally aggressive malignant mesenchymal neoplasm of primitive bone cells that have the ability to produce osteoid or immature bone
Papilloma (OM/PAP):
An exophytic, pedunculated, cauliflower-like benign neoplasm of epithelium; canine papillomatosis is thought to be due to infection with canine papillomavirus in typically young dogs; severe papillomatosis may be recognized in older dogs that are immunocompromised
Peripheral nerve sheath tumor (OM/PNT):
A group of neural tumors arising from Schwann cells or perineural fibroblasts (or a combination of both cell types) of the cranial nerves, spinal nerve roots or peripheral nerves; they may be classified as histologically benign or malignant
Peripheral odontogenic fibroma (OM/POF):
A benign mesenchymal odontogenic tumor associated with the gingiva and believed to originate from the periodontal ligament; characterized by varying amounts of inactive-looking odontogenic epithelium embedded in a mature, fibrous stroma, which may undergo osseous metaplasia; historically been referred to as fibromatous epulis or – when bone or tooth-like hard tissue present within the lesion – ossifying epulis
Plasma cell tumor (OM/PCT):
A proliferation of plasma cells, commonly occurring on the gingiva or dorsum of the tongue; also called plasmacytoma
Rhabdomyosarcoma (OM/RBM):
A malignant neoplasm of skeletal muscle or embryonic mesenchymal cells”
Squamous cell carcinoma (OM/SCC):
An invasive, malignant epithelial neoplasm of the oral epithelium with varying degrees of squamous differentiation
Undifferentiated neoplasm (OM/UDN):
A malignant neoplasm whose cells are generally immature and lack distinctive features of a particular tissue type