Figure 4 - uploaded by Robert Barigye
Content may be subject to copyright.
Gingival mass from the right maxilla of an 8-yearold Labrador Retriever dog. Neoplastic cells stained remarkably negative for cytokeratin. Note the intensely cytokeratin reactive stratified squamous epithelium overlying the area of neoplasia. A low-grade inflammatory response is clearly discernible. Immunohistochemistry. Bar 5 2000 mm.
Source publication
Odontogenic myxoma (OM) was diagnosed in an 8-year-old Labrador Retriever dog with an ulcerohemorrhagic mass located on the caudal area of the right maxillary gingiva. The neoplasm was characterized by a low mitotic index and moderate numbers of spindle, stellate, and round cells that were sparsely distributed in an alcian blue reactive myxomatous...
Similar publications
Leiomyosarcoma (LMS) is a rare mesenchymal malignancy, of which 3–10% of cases occur in the head and neck region. We report a 22-year-old woman who was referred to the University Hospital of Siena, Italy, in 2016 with an ostensibly benign asymptomatic lump on the mandibular gingiva. The lesion grew rapidly, causing otalgia in the right ear. An exci...
Citations
... 22 Differential diagnoses for OM in man and animals include ameloblastoma, a myxomatous follicular sac, hyperplastic dental follicles, odontogenic fibroma, odontogenic keratocyst, low-grade myxoid fibrosarcoma, myxoid lipomas and liposarcomas, and myxoid nerve sheath tumor. 1,28,32,40,43 Other tumors such as rhabdomyosarcomas and chrondrosarcomas exhibit myxoid degeneration, but their cells do not generally retain a stellate shape the way a pure myxoma does. 22 If the OM is associated with an unerupted tooth, it may need to be distinguished from a dentigerous cyst. ...
... 2 Vimentin is a 58-kD protein present in mesenchymal cells. 39,40 Studies have found that human OMs test positive for vimentin and smooth-muscle actin. 39 Two of the reported canine OMs underwent immunohistochemical evaluation. ...
... One tested positive for smooth muscle actin and cytokeratin and the other was negative for both markers. 40,41 Immunohistochemistry can also be helpful in ruling out rare nerve sheath myxomas, as neural proteins are not expressed by OMs. 28 However, it should be noted that there is no specific immunohistochemical marker that would confirm an odontogenic mesenchymal origin. 2 In the 4 reported cases of canine OM and for the single case report of a nonhuman primate, metastasis to the lungs or regional lymph nodes was not mentioned. ...
An inflammatory gingival mass surrounding resorbing teeth was diagnosed via biopsy in a 9-year-old domestic shorthair cat. A dorsal rim excision was performed to remove the entire mass with associated teeth and bone. Histopathological diagnosis of the en bloc tissue revealed an odontogenic fibromyxoma. Extensive literature review revealed few case reports of companion animals with this neoplasm, and none in a feline patient. This report documents the clinical presentation, diagnostic differentials, surgical therapy, and long-term follow-up of an odontogenic fibromyxoma in a cat.
There are multiple reports of gastric neuroendocrine carcinoma in bearded dragons (Pogona spp), but other types of alimentary neoplasia are rarely reported. In a retrospective study, we identified 51 cases of neoplasia, including gastric (n = 26), oral (n = 18), intestinal (n = 13), oesophageal (n = 3) and cloacal (n = 2) neoplasms. Round cell neoplasia was diagnosed in the alimentary tract in 14 cases, all of which had extra-alimentary involvement, most commonly in the liver, lung, spleen and kidney, and was considered to be the cause of death or euthanasia in all cases. Oral neoplasms included sarcoma, adenomatous polyp, round cell neoplasia, fibromatous epulis of periodontal ligament origin and myxoma. Apart from disseminated round cell neoplasia, all the oral neoplasms, including sarcomas, were not associated with death or euthanasia and had a good to excellent prognosis. Oesophageal neoplasms included round cell neoplasia. Gastric neoplasms included neuroendocrine carcinoma, round cell neoplasia, adenocarcinoma and sarcoma. Intestinal neoplasms included round cell neoplasia, sarcoma, adenocarcinoma and metastatic sarcoma. All oesophageal, gastric and intestinal neoplasms were associated with death or euthanasia and had a poor to grave prognosis. Cloacal neoplasms included round cell tumours and squamous cell carcinoma, and all were primary alimentary tumours except for the round cell tumours and one metastatic sarcoma. Round cell neoplasia and gastric neuroendocrine carcinoma were the most common diagnoses. Sarcomas and polyps were common in the oral cavity and rare to absent elsewhere. Adenocarcinoma was rare and only identified in the stomach and intestines.
Equine sinonasal myxomas (SNM) are very rare; only a few cases/small case series are reported in veterinary literature. The purpose of this report is to describe the diagnostic and surgical procedure adopted to approach the neoplastic mass in a case of equine SNM.
A 5-year-old, Murgese gelding was presented with mild serous nasal discharge, minimal facial swelling, decreased airflow from the right nostril and dull frontal sinus percussion.
Diagnostic imaging, including endoscopy, revealed a pale mass in the caudal portion of the right middle meatus, which developed inside the right concho-frontal sinus and nasal cavity and deviated the nasal septum to the left side. A large frontonasal bone flap was created with the horse in general anesthesia, aiming to remove the lesion and perform further diagnostic investigation. The mass had the shape of a small orange, the caudodorsal and rostral part having a hard wall, while the ventral part being friable; the inside was hollow, containing a viscous and transparent liquid.
Surgical excision was broad but incomplete, therefore after surgery, a standing trans-endoscopic diode laser irradiation and photoablation of small residual lesions per nasum were performed.
Microscopically, the mass consisted of spindle-shaped cells, loosely arranged within an abundant, light blue myxoid matrix. On the basis of clinical and pathological findings, the diagnosis of sinonasal myxoma was made. Although benign and slowly growing, myxomas usually tend to infiltrate the surrounding tissues; as a consequence, recurrence is very likely after surgical excision.
In the case described herein, the combination of a surgical excision, trans-endoscopic diode laser irradiation and photoablation provided a positive outcome, until at least 14 months after surgery.
Individual odontogenic tumors can share substantial morphologic overlap with one another and the precise diagnosis often hinges upon the identification of key histologic features like the presence or absence of the mineralized dental matrices. The odontogenic mineralized matrices can be derived from either the ectoderm and/or ectomesenchyme. The odontogenic tissue groups include: odontogenic epithelium, mineralized dental matrices, dental papilla, and dental follicle. The most commonly diagnosed odontogenic tumors in veterinary species are those that are principally comprised of odontogenic epithelium. This group includes conventional ameloblastoma, canine acanthomatous ameloblastoma, and amyloid producing ameloblastoma. In veterinary pathology, the term cementoblastoma has been used as a de facto synonym for another problematic term cementoma. The diagnosis of cementoblastoma is dependent upon the proliferative tissue arising from the outer surface of a tooth root and the pathologist's ability to accurately identify pathologic cementum in tissue sections.
The alimentary tract includes the oral cavity, esophagus, stomach, intestine, and rectum. These structures all share the same basic structure and consist of an epithelial-lined cavity supported by a submucosa. This submucosa is surrounded by bone in parts of the oral cavity and by muscle in the rest of tract. Because of this consistent basic structure, tumors that develop within the tubular alimentary tract can be subdivided into those of the epithelium and those that develop within the supporting mesenchymal tissue. Cancer staging requires assessment of regional lymph nodes for the presence of metastases. Papillomas of the oral cavity can be subdivided into squamous papillomas that are benign neoplasms and viral papillomas that are hyperplastic lesions caused by papillomavirus infection. Squamous cell carcinomas are the most common oral neoplasm of cats, horses, and the production animal species. They are the second most common malignant oral neoplasm of dogs.
Case report:
A 9-year-old male Bull Terrier was presented for a 3-month history of a progressive, non-painful conjunctival mass of the right eye. The mass was exophytic and located in the temporal bulbar conjunctiva. No adhesion to the sclera was detected. A presumptive clinical diagnosis of a conjunctival neoplasia was made. Complete physical and ophthalmological examinations of the dog, as well as complete blood count, serum biochemical analysis, urinalysis, thoracic radiography, echocardiography and abdominal ultrasonography, were performed. The mass was surgically removed and a double freeze-thaw cycle of cryotherapy was performed locally. Histological examination of the removed tissue showed a well-delineated, non-encapsulated mass composed of spindle cells in loose myxomatous stroma. No nuclear atypia was observed in the tumour cells. A positive Alcian blue stain confirmed the mucin origin of the stroma. Tumour cells stained positive on immunohistochemistry for vimentin and negative for cytokeratins. A diagnosis was made of conjunctival myxoma. No evidence of local recurrence or distant metastases was identified during the 24-month follow-up period.
Conclusion:
To the best of the authors' knowledge, this is the first report on a conjunctival myxoma in dogs.
Accurate identification of odontogenic tumors is critical for productive communication and an important foundation for useful comparative epidemiologic studies of odontogenic tumors in both domestic animals and humans. This manuscript illuminates the subject of veterinary odontogenic tumor nomenclature and will serve as a foundation for future updates in nomenclature and classification of odontogenic tumors.
