Oral Pathology - Inflammatory, Neoplastic, Other Lesions

Topics available:

Oral Inflammatory Diseases
Autoimmune Oral Diseases
Oral Tumors
Other Oral Pathology

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Abbeviations to be used in AVDC Case Logs are shown in (blue brackets)

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Oral Inflammation

Note that a definitive diagnosis of inflammation often cannot be made based on physical examination findings alone.

Oral and oropharyngeal inflammation is classified by location:

Gingivitis: Inflammation of gingiva

Periodontitis: Inflammation of non-gingival periodontal tissues (i.e. the periodontal ligament and alveolar bone)

Alveolar mucositis: Inflammation of alveolar mucosa (i.e., mucosa overlying the alveolar process and extending from the mucogingival junction without obvious demarcation to the vestibular sulcus and to the floor of the mouth)

Sublingual mucositis: Inflammation of mucosa on the floor of the mouth

Labial/buccal mucositis: Inflammation of lip/cheek mucosa

Caudal mucositis: Inflammation of mucosa of the caudal oral cavity, bordered medially by the palatoglossal folds and fauces, dorsally by the hard and soft palate, and rostrally by alveolar and buccal mucosa

Stomatitis (ST): Inflammation of the mucous lining of any of the structures in the mouth; in clinical use the term should be reserved to describe wide-spread oral inflammation (beyond gingivitis and periodontitis) that may also extend into submucosal tissues (e.g., marked caudal mucositis extending into submucosal tissues may be termed caudal stomatitis (ST/CS). Note: The fauces are defined as the lateral walls of the oropharynx that are located medial to the palatoglossal folds. The areas lateral to the palatoglossal fold, commonly involved in feline stomatitis, are not the fauces.

Contact mucositis and contact mucosal ulceration (CU): Lesions in susceptible individuals that are secondary to mucosal contact with a tooth surface bearing the responsible irritant, allergen, or antigen. They have also been called “contact ulcers” and “kissing ulcers”.

Palatitis: inflammation of mucosa covering the hard and/or soft palate

Glossitis: inflammation of mucosa of the dorsal and/or ventral tongue surface

Osteomyelitis (OST):
Inflammation of the bone and bone marrow

Inflammation of the lip (including the mucocutaneous junction area and skin of the lip)

Tonsilitis (TON/IN): Inflammation of the palatine tonsil

Pharyngitis (PHA/IN): inflammation of the pharynx

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Autoimmune Conditions Affecting the Mouth

Pemphigus vulgaris (PV): Autoimmune disease characterized histologically by intraepithelial blister formation (after breakdown or loss of intercellular adhesion), biochemically by evidence of circulating autoantibodies against components of the epithelial desmosome-tonofilament complexes, and clinically by the presence of vesiculobullous and/or ulcerative oral and mucocutaneous lesions

Bullous pemphigoid (BUP): Autoimmune disease characterized histologically by subepithelial clefting (separation at the epithelium-connective tissue interface), biochemically by evidence of circulating autoantibodies against components of the basement membrane, and clinically by the presence of erythematous, erosive, vesiculobullous and/or ulcerative oral lesions

Lupus erythematosis (LE): Autoimmune disease characterized histologically by basal cell destruction, hyperkeratosis, epithelial atrophy, subepithelial and perivascular lymphocytic infiltration and vascular dilation with submucosal edema, biochemically by the evidence of circulating autoantibodies against various cellular antigens in both the nucleus and cytoplasm, and clinically by the presence of acute lesions (systemic LE) to skin, mucosa and multiple organs or chronic lesions (discoid LE) mostly confined to the skin of the face and mucosa of the oral cavity

Masticatory muscle myositis (MMM): Autoimmune disease affecting the temporal, masseter, and medial and lateral pterygoid muscles of the dog. The term masticatory myositis is an acceptable alternative

Oral Tumors

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.

Abbreviations to be used in AVDC case Logs are shown in (blue in brackets).

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

Diagnostic and Non-Surgical Treatment Procedures

Biopsy (B): Removal of tissue from a living body for diagnostic purposes. The term has also been used to describe the tissue being submitted for evaluation

Guided biopsy: Using computed tomography or ultrasonography to guide an instrument to the selected area for tissue removal

Surface biopsy (B/S): Removal of tissue brushed, scraped or obtained by an impression smear from the intact or cut surface of a tissue in question

Needle aspiration (B/NA): Removal of tissue by application of suction through a hollow needle attached to a syringe

Needle biopsy (B/NB): Removal of tissue by puncture with a hollow needle

Core needle biopsy (B/CN): Removal of tissue with a large hollow needle that extracts a core of tissue

Bite biopsy (B/B): Removal of tissue by closing the opposing ends of an instrument

Punch biopsy (B/P): Removal of tissue by a punch-type instrument

Incisional biopsy (B/I) Removal of a selected portion of tissue by means of surgical cutting

Excisional biopsy (B/E): Removal of the entire tissue in question by means of surgical cutting Guided biopsy – Using computed tomography or ultrasonography to guide an instrument to the selected area for tissue removal

Radiotherapy (RTH): Use of ionizing radiation to control or kill tumor cells; also called radiation therapy

Chemotherapy (CTH): Use of cytotoxic anti-neoplastic drugs (chemotherapeutic agents) to control or kill tumor cells

Immunotherapy (ITH): Use of the immune system to control or kill tumor cells

Radiography (RAD): Two-dimensional imaging of dental, periodontal, oral and maxillofacial structures using an X-ray machine and radiographic films, sensor pads or phosphor plates

Computed tomography (CT): A method of medical imaging that uses computer-processed X-rays to produce tomographic images or 'slices' of specific areas of the body; digital geometry processing is used to generate three-dimensional images of an object of interest from a large series of two-dimensional X-ray images taken around a single axis of rotation

Cone-beam CT (CT/CB): Variation of traditional CT that rotates around the patient, capturing data using a cone-shaped X-ray beam

Magnetic resonance imaging (MRI): A method of medical imaging that uses the property of nuclear magnetic resonance to image nuclei of atoms inside the body

Ultrasonography (US): A method of medical imaging of deep structures of the body by recording the echoes of pulses of ultrasonic waves directed into the tissues and reflected by tissue planes where there is a change in density

Scintigraphy (SCI): A method of medical imaging that uses radioisotopes taken internally (e.g., by mouth, injection, inhalation), and the emitted radiation is captured by external detectors (gamma cameras) to form two-dimensional images


Surgical Treatment Procedures for Oral Tumors

Surgery (S): Branch of medicine that treats diseases, injuries and deformities by manual or operative methods

Buccotomy (BUC): Incision through the cheek (for example to gain access to an intraoral procedure)

Cheiloplasty/commissuroplasty (CPL): Reconstructive surgery of the lip/lip commissure

Commissurotomy (COM): Incision through the lip commissure (for example to gain access to an intraoral procedure)

Partial mandibulectomy (S/M): Surgical removal (en block) of part of the mandible and surrounding soft tissues

Dorsal marginal mandibulectomy (S/MD): A form of partial mandibulectomy in which the ventral border of the mandible is maintained; also called marginal mandibulectomy or mandibular rim excision

Segmental mandibulectomy (S/MS): A form of partial mandibulectomy in which a full dorsoventral segment of the mandible is removed

Bilateral partial mandibulectomy (S/MB): Surgical removal of parts of the left and right mandibles and surrounding soft tissues

Total mandibulectomy (S/MT): Surgical removal of one mandible and surrounding soft tissues

Partial maxillectomy (S/X): Surgical removal (en block) of part of the maxilla and/or other facial bones and surrounding soft tissues

Bilateral partial maxillectomy (S/XB): Surgical removal of parts of the left and right maxillae and/or other facial bones and surrounding soft tissues

Partial palatectomy (S/P): Partial resection of the palate


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Other Oral Pathology

Chewing lesion (CL): Mucosal lesion resulting from self-induced bite trauma on the cheek (CL/B), lip (CL/L), palate (CL/P) or tongue/sublingual region (CL/T)

Eosinophilic granuloma (EOG): Referring to conditions affecting the lip/labial mucosa (EOG/L), hard/soft palate (EOG/P), tongue/sublingual mucosa (EOG/T), and skin that are characterized histopathologically by the presence of an eosinophilic infiltrate

Pyogenic granuloma (PYO): Inflammatory proliferation at the vestibular mucogingival tissues of the mandibular first molar tooth (in the cat probably due to malocclusion and secondary traumatic contact of these tissues by the ipsilateral maxillary fourth premolar tooth)

Erythema multiforme (EM): Typically drug-induced hypersensitivity reaction characterized by erythematous, vesiculobullous and/or ulcerative oral and skin lesions

Calcinosis circumsctripta (CC): Circumscribed areas of mineralization characterized by deposition of calcium salts (e.g., in the tip of the tongue)

Retrobulbar abscess (RBA): Abscess behind the globe of the eye

Retropharyngeal abscess (RPA): Abscess behind the pharynx

Craniomandibular osteopathy (CMO): Disease characterized by cyclical resorption of normal bone and excessive replacement by immature bone along mandibular, temporal and other bone surfaces in immature and adolescent dogs

Calvarial hyperostosis (CHO): Disease characterized by irregular, progressive proliferation and thickening of the cortex of the bones forming the calvarium in adolescent dogs

Fibrous osteodystrophy (FOD): Disease characterized by the formation of hyperostotic bone lesions, in which deposition of unmineralized osteoid by hyperplastic osteoblasts and production of fibrous connective tissue exceed the rate of bone resorption; usually due to primary or secondary hyperparathyroidism; resulting in softened, pliable and distorted bones of the face (“rubber jaw”, “bighead” or “bran disease”)

Periostitis ossificans (PEO): Periosteal new bone formation in immature dogs, manifesting clinically as (usually) unilateral swelling of the mid to caudal body of the mandible and radiographically as two-layered (double) ventral mandibular cortex

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