Lesions of the oral cavity of dogs: 720 cases / Lesões da cavidade oral de cães: 720 casos

Seven hundred twenty cases of oral cavity lesions in dogs were diagnosed from 2015 to 2020 in Distrito Federal, Brazil. Four hundred thirty-two (60%) lesions were neoplastic, and 288 (40%) were non-neoplastic. Of the neoplasms, 229 (53%) were considered malignant and 203 (47%) benign, affecting mainly males, of 43 different breeds, with an average age of 9.4 years, mainly the gum and lip. Melanoma was the most (96/432, 22.2%) commonly diagnosed neoplasm, followed by peripheral odontogenic fibroma (68/432, 15.7%), papilloma (63/432, 14.5%) and squamous cell carcinoma (SCC) (56/432, 12.9%). Non-neoplastic lesions also affected males predominantly, from 41 different breeds, with an average age of 8.9 years, mainly in the gums, lip, and tongue. These lesions were diagnosed as inflammatory (230/288, 79.8%), hyperplastic (47/288, 16.3%) and other lesions (11/288, 3.8%).

Foram estudados 720 casos de lesões na cavidade oral em cães diagnosticados entre 2015 e 2020, no Distrito Federal. Dessas alterações, 432 (60%) foram neoplásicas e 288 (40%) não neoplásicas. Dentre os neoplasmas, 229 (53%) foram consideradas malignos e 203 (47%) benignos, acometendo principalmente machos, de 43 raças diferentes, com idade média 9,4 anos, afetando principalmente gengiva e lábio. Melanoma foi o neoplasma mais comumente diagnosticado (96/432; 22,2%), seguido do fibroma odontogênico periférico (68/432; 15,7%), papiloma (63/432; 14,5%) e carcinoma de células escamosas (56/432; 12,9%). As lesões não neoplásicas também acometeram predominantemente machos, de 41 raças diferentes, com idade média 8,9 anos, afetando principalmente gengiva, lábio e língua. Essas lesões foram diagnosticadas como inflamatórias (230/288; 79,8%), hiperplásicas (47/288; 16,3%) e como outras alterações (11/288; 3,8%).

Neoplasia de ducto nasolacrimal em uma cadela / Nasolacrimal duct neoplasm in a bitch

Background: Nasolacrimal duct tumors are divided into primary and secondary, with primary tumors being rare in all species. Secondary involvement of the lacrimal sac and duct can occur from any skin lesion involving the eyelid and/or conjunctiva and from any neoplastic process involving the paranasal sinuses. Lacrimal sac metastatic lesions may originate from any distant site and include carcinomas or melanomas, with squamous cell carcinoma being the most common type. The objectives of the present report were to describe a case of squamous cell carcinoma in the nasolacrimal duct and to emphasize the importance of a good ophthalmic evaluation. Case: A 16-year-old spayed bitch white poodle was presented to the veterinary clinic. The owner complained that the animal had epiphora and mucoid secretion in the right eye, eyelid hyperemia in both eyes, and sporadic sneezing with blood. On ophthalmic examination, the animal was initially diagnosed with nasolacrimal duct obstruction and right eye (OD) blepharitis and OU uveitis. Fourteen days after the first evaluation, the nasolacrimal duct region increased, with the presence of bloody secretion. Biomicroscopy showed nodules inside the lacrimal duct, in the punctum region. The animal was sedated to obtain a fragment of the nodule for histopathological analysis, and a subsequent oral cavity evaluation identified a nodule in the transition region between the 4th premolar and 1st molar, which was sent for cytology. Cytology of the medial corner region of the RE showed epithelial and mesenchymal cells with malignancy characteristics, and the biopsy was suggestive of malignant epithelial neoplasia (carcinoma). A surgical procedure for nodule resection was ruled out because bone involvement was extensive, and chemotherapy was selected. The patient died 2 months after the 1st consultation. The diagnosis was confirmed through necropsy via immunohistochemical tests, demonstrating squamous cell carcinoma (SCC) both in the mouth and the nasal and ocular sinuses. Discussion: The most common conditions affecting the nasolacrimal drainage system in dogs are those causing obstructions. These may be congenital, arising from a developmental defect of micropunctum or agenesis of the punctum, they may be acquired, arising from infection and inflammation. SCC is a malignant neoplasm originating in the stratified squamous epithelium. The predisposing factors in cats and dogs include lack of adnexal pigmentation and, possibly, chronic irritation of the ocular surface. A light coat is considered a relevant factor, especially in regions with little hair coverage. In addition to a mass lesion, other clinical signs of eyelid or ocular surface tumors may include epiphora, conjunctival vascular injection, mucopurulent ocular discharge, 3rd eyelid protrusion, conjunctival/corneal roughness or ulceration, and corneal neovascularization or pigmentation. Clinical presentations are nonspecific. Neoplasms, whether nasal and/or in the maxillary sinus, can invade the nasolacrimal duct and spread to the nasal cavity, and neoplasms in the nasal cavity can invade the nasolacrimal duct. Ophthalmic evaluation along with good inspection of the oral cavity is a useful tool in the diagnosis of eye neoplasms that may have effects on the oral cavity or vice versa due to the strong association between them. Early diagnosis is crucial for the clinical or surgical management of each case of ophthalmic neoplasia and for therapeutic success.

Radiation therapy for advanced canine nasal planum squamous cell carcinoma: case report / A utilização da radioterapia no tratamento do carcinoma de células escamosas de plano nasal canino avançado: relato de caso

This case report describes the outcome of treatment of dogs with advanced (deeply invasive) nasal planum squamous cell carcinomas with palliative or definitive radiation therapy. All dogs were diagnosed with nasal planum squamous cell carcinoma by histopathology, and their owners declined aggressive surgery. Dogs were treated with a cobalt-60 unit, definitive-intent radiation protocol consisting of 15 daily fractions (Monday-Friday) of 2.8 Gy, and palliative radiation protocol consisting of 4 fractions of 8 Gy performed once a week. Three dogs had T3 tumors and three had T4 tumors according to the WHO staging system. Two dogs had tumor complete remission and four had tumor partial remission. Survival time of dogs submitted to radiation therapy was 95-417 days. Radiation acute side effects involved only mild epilation and cutaneous erythema in palliative protocols, and moist desquamation, epilation, mild rhinitis and oral mucositis in definitive-intent RT. Radiation therapy, especially palliative protocols, can be a treatment option for nasal planum squamous cell carcinoma in dogs, when the owner declines aggressive surgery. It may contribute to partial or complete tumor remission and better patient quality of life, even at advanced stages, leading to mild side effects.(AU)

Este relato descreve seis casos de carcinoma de células escamosas de plano nasal canino tratados com radioterapia definitiva ou paliativa. Em todos os casos, o diagnóstico definitivo foi feito mediante biópsia, e os tutores declinaram da cirurgia agressiva. A radioterapia foi realizada utilizando-se um equipamento de cobalto-60, e o protocolo definitivo consistiu de 15 frações de 2,8 Gy, cinco vezes por semana (segunda a sexta), enquanto o protocolo paliativo consistiu de quatro frações de 8 Gy, uma vez por semana. Seis cães foram tratados, entre os quais três tinham tumores em estágio T3 e três em estágio T4, de acordo com a tabela TNM da Organização Mundial da Saúde. Dois animais apresentaram remissão completa do tumor após o tratamento e quatro apresentaram remissão parcial. O tempo de sobrevida variou entre 95-417 dias, sendo que dois animais ainda estão vivos e em observação. Os efeitos colaterais da radioterapia foram apenas epilação e eritema leve, no protocolo paliativo, e epilação, radiodermite úmida, rinite e mucosite oral, no protocolo definitivo. A radioterapia, especialmente no protocolo paliativo, pode ser considerada uma opção de tratamento quando os tutores declinam da cirurgia agressiva. Ela pode contribuir para remissão (parcial ou completa) do tumor e melhor qualidade de vida do paciente, mesmo nos casos avançados, levando a efeitos colaterais mínimos.(AU)

Radiation therapy for advanced canine nasal planum squamous cell carcinoma: case report / A utilização da radioterapia no tratamento do carcinoma de células escamosas de plano nasal canino avançado: relato de caso

This case report describes the outcome of treatment of dogs with advanced (deeply invasive) nasal planum squamous cell carcinomas with palliative or definitive radiation therapy. All dogs were diagnosed with nasal planum squamous cell carcinoma by histopathology, and their owners declined aggressive surgery. Dogs were treated with a cobalt-60 unit, definitive-intent radiation protocol consisting of 15 daily fractions (Monday-Friday) of 2.8 Gy, and palliative radiation protocol consisting of 4 fractions of 8 Gy performed once a week. Three dogs had T3 tumors and three had T4 tumors according to the WHO staging system. Two dogs had tumor complete remission and four had tumor partial remission. Survival time of dogs submitted to radiation therapy was 95-417 days. Radiation acute side effects involved only mild epilation and cutaneous erythema in palliative protocols, and moist desquamation, epilation, mild rhinitis and oral mucositis in definitive-intent RT. Radiation therapy, especially palliative protocols, can be a treatment option for nasal planum squamous cell carcinoma in dogs, when the owner declines aggressive surgery. It may contribute to partial or complete tumor remission and better patient quality of life, even at advanced stages, leading to mild side effects.(AU)

Este relato descreve seis casos de carcinoma de células escamosas de plano nasal canino tratados com radioterapia definitiva ou paliativa. Em todos os casos, o diagnóstico definitivo foi feito mediante biópsia, e os tutores declinaram da cirurgia agressiva. A radioterapia foi realizada utilizando-se um equipamento de cobalto-60, e o protocolo definitivo consistiu de 15 frações de 2,8 Gy, cinco vezes por semana (segunda a sexta), enquanto o protocolo paliativo consistiu de quatro frações de 8 Gy, uma vez por semana. Seis cães foram tratados, entre os quais três tinham tumores em estágio T3 e três em estágio T4, de acordo com a tabela TNM da Organização Mundial da Saúde. Dois animais apresentaram remissão completa do tumor após o tratamento e quatro apresentaram remissão parcial. O tempo de sobrevida variou entre 95-417 dias, sendo que dois animais ainda estão vivos e em observação. Os efeitos colaterais da radioterapia foram apenas epilação e eritema leve, no protocolo paliativo, e epilação, radiodermite úmida, rinite e mucosite oral, no protocolo definitivo. A radioterapia, especialmente no protocolo paliativo, pode ser considerada uma opção de tratamento quando os tutores declinam da cirurgia agressiva. Ela pode contribuir para remissão (parcial ou completa) do tumor e melhor qualidade de vida do paciente, mesmo nos casos avançados, levando a efeitos colaterais mínimos.(AU)

Tumor venéreo transmissível canino com múltiplas localizações extragenitais / Canine Transmissible Venereal Tumor with Multiple Extragenital Locations

Background: Transmissible venereal tumor (TVT) is a neoplasm which primarily affects the genital mucosa of canines. However, this tumor has been described in several extragenital areas. Although there are no major difficulties to confirm a TVT when present in the genitalia, it can be confused with several conditions, either neoplastic or non-neoplastic, when located beyond the external reproductive organs. The involvement of multiple extragenital locations is poorly reported, which may compromise the tissues involved and hinder the establishment of a diagnostic conclusion. The study aimed to describe a case of multiple and extragenital TVT in dogs. Case: A two year old mongrel dog had a history of swollen nose and ocular abnormalities. The patient underwent physical examination followed by request of nose and eye cytology. The animal was euthanized and sent for autopsy; the material was intended for cytological diagnosis. It was found an increase in volume in the middle third of the nasal region. In the oral cavity, there was a tumor in the caudal third of the hard palate. Neoformations were also detected in the third eyelid. The nasal and eyelid cytological examination was compatible with TVT plasmacytoid pattern. During the necropsy, it was also detected tumors in the nasal cavity, occupying the space of turbinal bones Proliferation occurred even in the palatine bone and pharynx. In the visual system, the tumors did not involve other attachments or eyeball chambers There were no anatomical lesions In other areas. The cytopathology of all tumors presented diagnosis similar to the initial microscopic findings, thus characterizing a framework of multiple extragenital plasmacytoid TVT. Discussion: A study found that the nasal cavity and skin tissue were the locations most affected by the presentation of extragenital TVT. So, there was a similarity to the present case in relation to the shape of the nasal TVT; however, the occurrence in other sites such as the oral cavity and third eyelid is uncommon, although found in the patient reported. The extragenital location may appear regardless to genital lesions. In the examined animal, the placement of the TVT to extragenital areas such as nasal and ocular adnexa was justified by the fact that these regions correspond to anatomical sites exposed to direct physical contact for the acquisition of neoplastic cells, possibly because of the pre­mating behavior of the male toward the bitch that housed the tumor. As an intranasal neoplasia progresses, some signs, such as the swelling of the hard palate, are presented. Thus, in the current study, the proliferation showed in the oral cavity and the pharynx was regarded as an extension of local mechanical nasal cancer. Recent surveys have ranked the TVT as standard plasmocitoyd, linphocitoyd or mixed. It has been hypothesized that all TVTs start as linphocitoyd, become mixed and then plasmocytoid. The latter condition usually suggests the tumor presence for more than eight weeks, often being seen in non genitals. Accordingly, in the present case there was an agreement with the usual standard morfocelular and the extragenital aspect observed. This morphology suggested that the evolution of TVT showed up late. Although TVT is essentially related to the external reproductive organs, one should be alert to its exclusively extragenital presentation. This peculiar location can lead to a delayed diagnosis because of the similarity with affections of another nature.

Carcinoma de células escamosas na região frontal da cabeça em cabra / Squamous Cell Carcinoma in the Frontal Region of the Head in a Goat

Background: The squamous cell carcinoma is a malignant tumor of epidermal cells in which the cells show differentiation to keratinocytes. It is a common neoplasm affecting all domestic animals and other mammalian species. There are several factors that are associated with the development of a squamous cell carcinoma, including prolonged exposure to ultraviolet light, lack of pigment within the epidermis at the sites of tumor development, and lack of hair or a very sparse hair coat at the affected sites. They can appear anywhere on the animal's body predominantly in areas devoid of hair and ears, eyelids, nose and perineal area. Squamous cell carcinoma may occur in young animals, but the incidence increases with age. The cut surface of the tumor appears grainy, whitish or yellowish. These tumors are very infiltrative but rarely metastasize. Microscopically there is the characteristic feature of squamous cell carcinomas and well differentiated with abundant proliferation of stromal. The tumor is common in the horse, cow, cat, and dog, relatively uncommon in the sheep, and rare in the goat and pig. In sheep and goats there are few data in literature. This paper reports a case of squamous cell carcinoma in the frontal region of the head in a Pardo Alpino goat in Bahia. Case: An 6-year-old female Pardo Alpino goat was made euthanasia and sent for necropsy to the Laboratório de Patologia Veterinária of Universidade Federal do Recôncavo da Bahia, Cruz das Almas (UFRB), Bahia, Brazil. According to the veterinarian the goat began to show a neoformation located in the front of the head. This period was performed surgical excision of the mass and cauterization, but the neoplasm recurred twice in succession. Due to the condition it was in, the animal was euthanized. The animal was necropsied and samples collected from the abdominal cavity, thoracic cavity, nervous system and integumentary system. The samples were fixed in 10% formalin, cleaved, processed routinely for histology, embedded in paraffin, cut at five microns thick and stained with hematoxylin and eosin. The necropsy was found mass measuring 5,0 x 3,5 x 3,5 cm in the frontal region of the head. The cut surface of the tumor had been firm and whitish. There were no metastasis in regional lymph nodes or others organs. Histopathological examination revealed a well-differentiated squamous cell carcinoma displaying central pearls of keratin and a dense fibrous stroma. The cytoplasm was abundant and eosinophilic with indistinct boundaries. Were observed 3-5 mitoses greater increase. Discussion: The diagnosis of squamous cell carcinoma of the goat was established by macroscopic and microscopic findings. In this report the neoplasm grew in the caudal region of the frontal sinus, near the spot where had been deshorned. The presence of squamous cell carcinoma located in the front of the head has not been reported in goats. In cattle there squamous cell carcinoma base of horn, diagnosis which could be considered in this case. These results are similar to those described by other authors. Was not found metastasis in regional lymph nodes and parenchymal organs. Most tumors, although invasive, do not show metastatic to regional lymph nodes. There are not papers in the literature of squamous cell carcinoma at this location.