Search

Spaying female and castrating male dogs, hereinafter referred to as neutering, is a US convention for the first year in the dogs life. Research on 35 breeds of dogs revealed that early neutering increases risks of joint disorders, such as hip dysplasia (HD), elbow dysplasia (ED), or cranial cruciate ligament (CCL) tear, or cancers, such as lymphosarcoma (LSA), mast cell tumor (MCT), hemangiosarcoma (has), or osteosarcoma (OSA), for some breeds. Joint disorder risks are heightened for some larger breeds and for mixed-breed dogs weighing more than 20 kg. Some breeds had elevated risks for cancers. Several other research teams have reported health complications associated with neutering. The study goal includes using the same methodology for data collection and analyses as in the study on 35 breeds for five additional dog breeds weighing at least 20 kg. The breeds were: German Short/Wirehaired Pointer, Mastiff, Newfoundland, Rhodesian Ridgeback, and Siberian Husky. Major differences among breeds appeared in vulnerability to joint disorders and cancers with early neutering: male and female Pointer breeds had elevated joint disorders and increased cancers; male Mastiff breeds had increased CCL and LSA and females had non-significant elevated CCL risks; female Newfoundland breeds had heightened risks for joint disorders and males had non-significant elevated risks; female Ridgeback breeds had heightened MCT with very early neutering; and Siberian Huskies showed no significant effects on joint disorders or cancers, but female breeds showed a non-significant but elevated CCL. Updated guidelines cover 40 dog breeds. These results further emphasize the importance of personalized decisions regarding the neutering of dogs, considering the dogs breed, sex, and context.

Glucocorticoid administration is a common clinical practice that attempts to decrease the inflammation associated with and improve the resectability of canine mast cell tumors (MCTs). However, the impact of neoadjuvant glucocorticoids on the histological features and proliferation indices of canine MCTs is unknown. The objective of this study was to evaluate changes in tumor grade, mitotic count, Ki67, AgNOR, and AgNORxKi67 scores following short-course anti-inflammatory neoadjuvant prednisone in canine patients with MCTs. This was a prospective single-arm pilot study. Client-owned dogs with treatment-naïve cytologically confirmed MCTs were enrolled. Patients underwent an initial incisional biopsy followed by a 10–14-day course of anti-inflammatory prednisone and surgical resection. All histological samples were randomized, masked, and evaluated by a single pathologist. Unstained paired pre- and post-treatment samples were submitted to a commercial laboratory for Ki67 and AgNOR immunohistochemical analysis. There were 11 dogs enrolled with 11 tumors. There were no statistical differences between the pre- and post-treatment histological parameters of mitotic index, Ki67, AgNOR, or Ki67xAgNOR. There were no clinically significant alterations between pre-treatment and post-treatment in the assignment of tumor grades. A short course of anti-inflammatory prednisone does not appear to alter the histological parameters that affect grade determination or significantly alter the proliferation indices in canine MCTs.

Neutering (including spaying) of male and female dogs in the first year after birth has become routine in the U.S. and much of Europe, but recent research reveals that for some dog breeds, neutering may be associated with increased risks of debilitating joint disorders and some cancers, complicating pet owners' decisions on neutering. The joint disorders include hip dysplasia, cranial cruciate ligament tear or rupture, and elbow dysplasia. The cancers include lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. In previous studies on the Golden Retriever, Labrador Retriever and German Shepherd Dog, neutering before a year of age was associated with increased risks of one or more joint disorders, 2-4 times that of intact dogs. The increase was particularly seen with dogs neutered by 6 months of age. In female Golden Retrievers, there was an increase in one or more of the cancers followed to about 2-4 times that of intact females with neutering at any age. The goal of the present study was to expand and use the same data collection and analyses to cover an additional 29 breeds, plus three varieties of Poodles. There were major breed differences in vulnerability to neutering, both with regard to joint disorders and cancers. In most cases, the caregiver can choose the age of neutering without increasing the risks of these joint disorders or cancers. Small-dog breeds seemed to have no increased risks of joint disorders associated with neutering, and in only two small breeds (Boston Terrier and Shih Tzu) was there a significant increase in cancers. To assist pet owners and veterinarians in deciding on the age of neutering a specific dog, guidelines that avoid increasing the risks of a dog acquiring these joint disorders or cancers are laid out for neutering ages on a breed-by-breed and sex basis.

Neutering (including spaying) of male and female dogs in the first year after birth has become routine in the U.S. and much of Europe, but recent research reveals that for some dog breeds, neutering may be associated with increased risks of debilitating joint disorders and some cancers, complicating pet owners' decisions on neutering. The joint disorders include hip dysplasia, cranial cruciate ligament tear or rupture, and elbow dysplasia. The cancers include lymphoma, mast cell tumor, hemangiosarcoma, and osteosarcoma. In previous studies on the Golden Retriever, Labrador Retriever and German Shepherd Dog, neutering before a year of age was associated with increased risks of one or more joint disorders, 2-4 times that of intact dogs. The increase was particularly seen with dogs neutered by 6 months of age. In female Golden Retrievers, there was an increase in one or more of the cancers followed to about 2-4 times that of intact females with neutering at any age. The goal of the present study was to expand and use the same data collection and analyses to cover an additional 29 breeds, plus three varieties of Poodles. There were major breed differences in vulnerability to neutering, both with regard to joint disorders and cancers. In most cases, the caregiver can choose the age of neutering without increasing the risks of these joint disorders or cancers. Small-dog breeds seemed to have no increased risks of joint disorders associated with neutering, and in only two small breeds (Boston Terrier and Shih Tzu) was there a significant increase in cancers. To assist pet owners and veterinarians in deciding on the age of neutering a specific dog, guidelines that avoid increasing the risks of a dog acquiring these joint disorders or cancers are laid out for neutering ages on a breed-by-breed and sex basis.

Mastocitomi su najučestaliji tumori kože pasa. Vode poreklo iz kostne srži, a zbog vrlo promenljivog biološkog ponašanja je predloženo nekoliko kriterijuma za njihovu klasifikaciju, uključujući histološku gradaciju i markere proliferacije ćelija. Mitotski indeks, prisustvo višejedarnih ćelija, ćelija sa bizarnim jedrom i kariomegalija su najvažniji parametri za klasifikaciju mastocitoma pasa na mastocitome visokog i niskog stepena maligniteta. Za potvrdu stepena maligniteta mastocitoma bitno je utvrditi i ekspresiju transmembranskog receptora kinaza tipa (KIT) koji igra značajnu ulogu u rastu i diferencijaciji mastocita, a koga kodira c-KIT protoonkogen. Kod mastocitoma visokog stepena maligniteta, osim membranske ekspresije KIT receptora, može se uočiti i aberantna citoplazmatska ekspresija. Ispitana su ukupno 52 mastocitoma pasa i 12 uzoraka nepromenjene kože pasa. Uzorci kože fiksirani u formalinu i ukalupljeni u parafinu su obojeni hematoksilineozinom. Ekspresija KIT receptora je ispitana primenom imunohistohemijske metode bojenja. Klasifikacija mastocitoma na mastocitome visokog i niskog stepena maligniteta je izvršena prema kriterijumima Kiupel-ove dvostepene klasifikacije, uzimajući u obzir i ekspresiju KIT receptora. Od ukupno 52 mastocitoma pasa 16 je bilo niskog stepena maligniteta, dok je 36 klasifikovano kao mastocitomi visokog stepena maligniteta, od kojih 19 mastocitoma pokazuje citoplazmatsku ekspresiju KIT receptora. Kod svih 16 mastocitoma niskog stepena maligniteta ispoljena je samo membranska ekspresija KIT proteina. Činjenica da je kod većine mastocitoma visokog stepena maligniteta ispoljena ekspresija KIT receptora u citoplazmi potvrđuje vezu između aberantne ekspresije KIT receptora i povećane ćelijske proliferacije. Prisustvo mitotskih figura, višejedarnih ćelija, bizarnih jedara i kariomegalije, kao i tip ekspresije KIT receptora predstavljaju ključne prognostičke parametre kod pasa sa mastocitomima., Mast cell tumors (MCTs) are one of the most common neoplasms in dogs. They originate from the bone marrow. Several criteria have been proposed for their classification, including histological grading and cell proliferation markers. The mitotic index, multiple nuclei, cells with bizarre nuclei and karyomegaly are the most important parameters for the classification of MCTs on high and low-grade malignancy. For the confirmation of MCT malignancy grade it is also important to determine the expression of the transmembrane kinase (KIT) receptor that has a significant role in the growth and differentiation of mast cell tumors. In high-grade malignancy MCTs in addition to membrane expression of the KIT receptor, aberrant cytoplasmic expression can be also observed. Fifty-two MCTs and 12 control samples of skin from dogs without MCTs were examined. Routinely processed tissue samples were stained with hematoxylin-eosin. Expression of KIT receptor was tested immunohistochemically. The classification of MCTs on high and low-grade malignancy was performed according to the Kiupel’s 2-tier classification and the expression of KIT receptors. Sixteen of 52 MCTs were of a low-grade malignancy, while thirty-six were classified as a high-grade malignancy of which 19 MCTs showed aberrant cytoplasm labelling of KIT receptor. All 16 low-grade malignancy MCTs had only membrane expression of KIT receptor. Most high-grade malignancy MCTs showed cytoplasmic KIT expression indicating the link between aberrant KIT expression and increased cell proliferation. The presence of mitotic figures, multinucleated cells, bizarre nuclei and karyomegaly, as well as KIT receptor expression pattern are the most important prognostic factors in dogs with mast cell tumor.

Mastocitomi su najučestaliji tumori kože pasa. Vode poreklo iz kostne srži, a zbog vrlo promenljivog biološkog ponašanja je predloženo nekoliko kriterijuma za njihovu klasifikaciju, uključujući histološku gradaciju i markere proliferacije ćelija. Mitotski indeks, prisustvo višejedarnih ćelija, ćelija sa bizarnim jedrom i kariomegalija su najvažniji parametri za klasifikaciju mastocitoma pasa na mastocitome visokog i niskog stepena maligniteta. Za potvrdu stepena maligniteta mastocitoma bitno je utvrditi i ekspresiju transmembranskog receptora kinaza tipa (KIT) koji igra značajnu ulogu u rastu i diferencijaciji mastocita, a koga kodira c-KIT protoonkogen. Kod mastocitoma visokog stepena maligniteta, osim membranske ekspresije KIT receptora, može se uočiti i aberantna citoplazmatska ekspresija. Ispitana su ukupno 52 mastocitoma pasa i 12 uzoraka nepromenjene kože pasa. Uzorci kože fiksirani u formalinu i ukalupljeni u parafinu su obojeni hematoksilineozinom. Ekspresija KIT receptora je ispitana primenom imunohistohemijske metode bojenja. Klasifikacija mastocitoma na mastocitome visokog i niskog stepena maligniteta je izvršena prema kriterijumima Kiupel-ove dvostepene klasifikacije, uzimajući u obzir i ekspresiju KIT receptora. Od ukupno 52 mastocitoma pasa 16 je bilo niskog stepena maligniteta, dok je 36 klasifikovano kao mastocitomi visokog stepena maligniteta, od kojih 19 mastocitoma pokazuje citoplazmatsku ekspresiju KIT receptora. Kod svih 16 mastocitoma niskog stepena maligniteta ispoljena je samo membranska ekspresija KIT proteina. Činjenica da je kod većine mastocitoma visokog stepena maligniteta ispoljena ekspresija KIT receptora u citoplazmi potvrđuje vezu između aberantne ekspresije KIT receptora i povećane ćelijske proliferacije. Prisustvo mitotskih figura, višejedarnih ćelija, bizarnih jedara i kariomegalije, kao i tip ekspresije KIT receptora predstavljaju ključne prognostičke parametre kod pasa sa mastocitomima., Mast cell tumors (MCTs) are one of the most common neoplasms in dogs. They originate from the bone marrow. Several criteria have been proposed for their classification, including histological grading and cell proliferation markers. The mitotic index, multiple nuclei, cells with bizarre nuclei and karyomegaly are the most important parameters for the classification of MCTs on high and low-grade malignancy. For the confirmation of MCT malignancy grade it is also important to determine the expression of the transmembrane kinase (KIT) receptor that has a significant role in the growth and differentiation of mast cell tumors. In high-grade malignancy MCTs in addition to membrane expression of the KIT receptor, aberrant cytoplasmic expression can be also observed. Fifty-two MCTs and 12 control samples of skin from dogs without MCTs were examined. Routinely processed tissue samples were stained with hematoxylin-eosin. Expression of KIT receptor was tested immunohistochemically. The classification of MCTs on high and low-grade malignancy was performed according to the Kiupel’s 2-tier classification and the expression of KIT receptors. Sixteen of 52 MCTs were of a low-grade malignancy, while thirty-six were classified as a high-grade malignancy of which 19 MCTs showed aberrant cytoplasm labelling of KIT receptor. All 16 low-grade malignancy MCTs had only membrane expression of KIT receptor. Most high-grade malignancy MCTs showed cytoplasmic KIT expression indicating the link between aberrant KIT expression and increased cell proliferation. The presence of mitotic figures, multinucleated cells, bizarre nuclei and karyomegaly, as well as KIT receptor expression pattern are the most important prognostic factors in dogs with mast cell tumor.

Background: The JAK-STAT pathway is a cellular signaling pathway, which acts normally in humans and animals in the control of multiple important functions. Dysregulation of this pathway has been identified in human cancers, as well as a limited number of veterinary cancers. Objectives: The aims of this study were to identify the presence and tentative activity of components of the JAK-STAT pathway in selected canine tumors. Methods: Formalin-fixed, paraffin-embedded samples from mast cell tumors (MCT), hemangiosarcomas (HSA), thyroid carcinomas, and apocrine gland anal sac adenocarcinomas (AGASACA) were obtained from the Diagnostic Histopathology Laboratory at the Virginia Maryland College of Veterinary Medicine. Immunohistochemistry was performed to evaluate protein levels of JAK1, phospho-JAK1, JAK2, phospho-JAK2, STAT3, and phospho-STAT3. Signalment, treatment information, and survival information was obtained from the medical record for each case. Results: Tumor samples were scored for percent positive neoplastic cells. Positive staining was seen for all antibodies in all tumor types, with expression of JAK1, STAT3, and pSTAT3 being highest overall for all tumor types. Significant associations were seen between JAK1 and survival time in MCT (p = 0.03), pJAK1 and survival time in HSA (p = 0.009) and MCT (p = 0.04), and pSTAT3 and metastasis in MCT (p = 0.0008). Conclusions: The finding of positive staining for the components of the JAK-STAT pathway in the tumor samples evaluated indicates presence and tentative activity of this pathway in the studied cancers. Further study of JAK1, pJAK1, and pSTAT3 should be pursued to evaluate their potential as therapeutic targets.

Calazans S.G., Fonseca-Alves C.E., Rodrigues P.C. & Magalhães G.M. [Canine cutaneous mast cell tumor, with progression of low-grade to high-grade - Case report.] Mastocitoma cutâneo canino, com progressão de baixo grau para alto grau - Relato de caso. Revista Brasileira de Medicina Veterinária, 38(2):147-152, 2016. Curso de Medicina Veterinária, Universidade de Franca, Av. Dr. Armando Salles Oliveira, 201, Parque Universitário, Franca, SP 14404-600, Brasil. E-mail: sabryna.calazans@gmail.com Mast cell tumor is a common canine cutaneous neoplasm with variable biological behavior. Many studies in the literature evaluate predictive and prognostic factors for this neoplasm. The tumoral progression is an important phenomenon for many neoplasms, and in the canine prostatic neoplasm and squamous cell carcinoma this progression is well defined, however, don’t have a classic describe in the cutaneous canine mast cell tumors. This study reports the diagnostic and treatment assessment of cutaneous mast cell tumor in a dog presenting tumor progression. A five years old Shar Pei dog, male, 20 kg, was admitted to the veterinary clinic presenting chronic alopecia and pruritus and cutaneous nodules in left pelvic limb. The tumor was surgically excised and histopathological and immunohistochemistry examination diagnosed a low grade of mast cell tumor, membrane localization of c-KIT (KIT I) and ki-67 under 23 cells, in five high magnification fields. The tumor recurred five months after initial diagnostic presenting a nodule in the surgical region. After cytological examination, mast cell tumor was confirmed and, cytoreductive chemotherapy was started. The patient presented no response to treatment and new nodules arrised, so surgical resection was performed. Histopathological and immunohistochemistry examination was performed again demonstrating tumor progression as high grade mast cell tumor, citoplasmatic localization in c-KIT (KIT III) and ki-67 superior 23 cells. A, O mastocitoma é a neoplasia cutânea mais comum em cães e apresenta comportamento biológico variável. Muitos trabalhos na literatura buscam definir marcadores prognósticos e preditivos para esta neoplasia, no entanto, apesar dos avanços obtidos nos últimos anos é difícil predizer recidivas e metástases deste tumor. A progressão tumoral também é um aspecto importante para as diversas neoplasias, e em neoplasias prostáticas caninas e no carcinoma de células escamosas essa progressão é bem definida, no entanto, em relação ao mastocitoma cutâneo canino não há uma descrição clássica dessa progressão. Devido à importância dessa neoplasia em cães, o presente trabalho descreve a conduta diagnóstica e abordagem terapêutica de um caso de mastocitoma cutâneo canino com progressão do grau histológico. Um cão da raça Shar-pei, cinco anos de idade, não castrado, pesando 20 kg, foi encaminhado para atendimento, com histórico de alopecia e prurido crônico, apresentando nódulo localizado em membro pélvico esquerdo. O nódulo foi retirado cirurgicamente e o material foi encaminhado ao exame histopatoló- gico e imunoistoquímico revelando mastocitoma de baixo grau, marcação membranosa de c-kit (KIT I) e proliferação celular (ki-67) menor que 23 células, contadas em cinco campos de grande aumento. Cinco meses após diagnóstico inicial, o animal retornou apresentando nódulo aderido e localizado na ferida cirúrgica. Após diagnóstico de mastocitoma através do exame citológico, iniciou-se quimioterapia objetivando citorredução, no entanto, notou-se crescimento tumoral. Como a tentativa de redução tumoral não foi satisfatória e surgiram novos nódulos, optou-se por realizar retirada cirúrgica. Em nova avaliação histopatológica e imunoistoquímica, verificou-se progressão tumoral, com diagnóstico de mastocitoma de alto grau, marcação citoplasmática de c-kit (KIT III) e proliferação celular (ki-67) maior que 23 células. Após o procedimento cirúrgico, houve recidiva tumoral e iniciou- -se protocolo

Histopathological examination, grading, immunohistochemical staining and molecular genetic examinations are the proposed criteria that should be used for cutaneous mast cell tumors (CMCTs) classification. The presence of aberrant CD117 expression and mutations of the c-kit proto-oncogene could be an indicative parameter for final histological grading. Determination of the connection between the localization of KIT receptor expression and the histological grade of CMCTs without c-kit proto-oncogene mutations was the main goal of this study. The study included twenty four CMCTs and six control skin samples from 30 dogs of different ages, breed and sex. Formalinfixed and paraffin-embedded tissue samples were stained with hematoxylin-eosin and toluidine blue and immunohistochemically tested for CD117 expression. DNA was extracted from the same paraffin blocks and subsequent polymerase chain reaction amplification was performed using PE1 and PE2 primers. Degree of malignancy was determined based on the presence of mitotic figures, multinucleated cells, bizarre nuclei and karyomegaly in 10 high power fields. Based on histological features, fourteen of 24 CMCTs were of a high histological grade, while ten were classified as a lowgrade malignancy. CD117 cytoplasmic expression was observed in nine of fourteen high-grade malignancy CMCTs, which confirms the link between the aberrant CD117 expression and increased cell proliferation., Histopatološko ispitivanje, gradacija, imunohistohemijsko bojenje i molekularno genetska ispitivanja su predloženi kriterijumi za klasifikaciju kutanih mastocitoma pasa. Prisustvo aberantne ekspresije CD117 i mutacija c-kit protoonkogena moglo bi da bude indikativni parameter za finalnu histopatološku klasifikaciju mastocitoma. Glavni cilj ispitivanja je određivanje povezanosti mesta ekspresije KIT receptora i histološkog gradusa mastocitoma bez c-kit mutacija. Ispitivanjima su obuhvaćena 24 mastocitoma i 6 kontrolnih isečaka kože uzorkovanih od ukupno 30 odraslih pasa različitog uzrasta, rase i pola. Uzorci fiksirani u formalinu i ukalupljeni u parafinske kalupe su bojeni hematoksilin-eozinom, toluidin plavo metodom i imunohistohemijski primenom CD117 antitela. DNK je izolovana iz istih parafinskih kalupa, a PCR amplifikacija je izvršena primenom specifičnih prajmera PE1 i PE2. Stepen malignosti je utvrđen na osnovu prisustva mitotskih figura, multinuklearnih ćelija, ćelija sa bizarnim jedrom i kariomegalije na 10 polja velikog uveličanja. Na osnovu histopatoloških osobina, 14 od 24 mastocitoma su svrstani u visoki stepen maligniteta, dok je 10 mastocitoma niskog stepena maligniteta. Citoplazmatska ekspresija CD117 je uočena kod 9 od 14 mastocitoma visokog stepena maligniteta, što potvrđuje vezu između aberantne ekspresije CD117 i povećane ćelijske proliferacije.

Histopathological examination, grading, immunohistochemical staining and molecular genetic examinations are the proposed criteria that should be used for cutaneous mast cell tumors (CMCTs) classification. The presence of aberrant CD117 expression and mutations of the c-kit proto-oncogene could be an indicative parameter for final histological grading. Determination of the connection between the localization of KIT receptor expression and the histological grade of CMCTs without c-kit proto-oncogene mutations was the main goal of this study. The study included twenty four CMCTs and six control skin samples from 30 dogs of different ages, breed and sex. Formalinfixed and paraffin-embedded tissue samples were stained with hematoxylin-eosin and toluidine blue and immunohistochemically tested for CD117 expression. DNA was extracted from the same paraffin blocks and subsequent polymerase chain reaction amplification was performed using PE1 and PE2 primers. Degree of malignancy was determined based on the presence of mitotic figures, multinucleated cells, bizarre nuclei and karyomegaly in 10 high power fields. Based on histological features, fourteen of 24 CMCTs were of a high histological grade, while ten were classified as a lowgrade malignancy. CD117 cytoplasmic expression was observed in nine of fourteen high-grade malignancy CMCTs, which confirms the link between the aberrant CD117 expression and increased cell proliferation., Histopatološko ispitivanje, gradacija, imunohistohemijsko bojenje i molekularno genetska ispitivanja su predloženi kriterijumi za klasifikaciju kutanih mastocitoma pasa. Prisustvo aberantne ekspresije CD117 i mutacija c-kit protoonkogena moglo bi da bude indikativni parameter za finalnu histopatološku klasifikaciju mastocitoma. Glavni cilj ispitivanja je određivanje povezanosti mesta ekspresije KIT receptora i histološkog gradusa mastocitoma bez c-kit mutacija. Ispitivanjima su obuhvaćena 24 mastocitoma i 6 kontrolnih isečaka kože uzorkovanih od ukupno 30 odraslih pasa različitog uzrasta, rase i pola. Uzorci fiksirani u formalinu i ukalupljeni u parafinske kalupe su bojeni hematoksilin-eozinom, toluidin plavo metodom i imunohistohemijski primenom CD117 antitela. DNK je izolovana iz istih parafinskih kalupa, a PCR amplifikacija je izvršena primenom specifičnih prajmera PE1 i PE2. Stepen malignosti je utvrđen na osnovu prisustva mitotskih figura, multinuklearnih ćelija, ćelija sa bizarnim jedrom i kariomegalije na 10 polja velikog uveličanja. Na osnovu histopatoloških osobina, 14 od 24 mastocitoma su svrstani u visoki stepen maligniteta, dok je 10 mastocitoma niskog stepena maligniteta. Citoplazmatska ekspresija CD117 je uočena kod 9 od 14 mastocitoma visokog stepena maligniteta, što potvrđuje vezu između aberantne ekspresije CD117 i povećane ćelijske proliferacije.

Calazans S.G., Fonseca-Alves C.E., Rodrigues P.C. & Magalhães G.M. [Canine cutaneous mast cell tumor, with progression of low-grade to high-grade - Case report.] Mastocitoma cutâneo canino, com progressão de baixo grau para alto grau - Relato de caso. Revista Brasileira de Medicina Veterinária, 38(2):147-152, 2016. Curso de Medicina Veterinária, Universidade de Franca, Av. Dr. Armando Salles Oliveira, 201, Parque Universitário, Franca, SP 14404-600, Brasil. E-mail: sabryna.calazans@gmail.com Mast cell tumor is a common canine cutaneous neoplasm with variable biological behavior. Many studies in the literature evaluate predictive and prognostic factors for this neoplasm. The tumoral progression is an important phenomenon for many neoplasms, and in the canine prostatic neoplasm and squamous cell carcinoma this progression is well defined, however, don’t have a classic describe in the cutaneous canine mast cell tumors. This study reports the diagnostic and treatment assessment of cutaneous mast cell tumor in a dog presenting tumor progression. A five years old Shar Pei dog, male, 20 kg, was admitted to the veterinary clinic presenting chronic alopecia and pruritus and cutaneous nodules in left pelvic limb. The tumor was surgically excised and histopathological and immunohistochemistry examination diagnosed a low grade of mast cell tumor, membrane localization of c-KIT (KIT I) and ki-67 under 23 cells, in five high magnification fields. The tumor recurred five months after initial diagnostic presenting a nodule in the surgical region. After cytological examination, mast cell tumor was confirmed and, cytoreductive chemotherapy was started. The patient presented no response to treatment and new nodules arrised, so surgical resection was performed. Histopathological and immunohistochemistry examination was performed again demonstrating tumor progression as high grade mast cell tumor, citoplasmatic localization in c-KIT (KIT III) and ki-67 superior 23 cells. A, O mastocitoma é a neoplasia cutânea mais comum em cães e apresenta comportamento biológico variável. Muitos trabalhos na literatura buscam definir marcadores prognósticos e preditivos para esta neoplasia, no entanto, apesar dos avanços obtidos nos últimos anos é difícil predizer recidivas e metástases deste tumor. A progressão tumoral também é um aspecto importante para as diversas neoplasias, e em neoplasias prostáticas caninas e no carcinoma de células escamosas essa progressão é bem definida, no entanto, em relação ao mastocitoma cutâneo canino não há uma descrição clássica dessa progressão. Devido à importância dessa neoplasia em cães, o presente trabalho descreve a conduta diagnóstica e abordagem terapêutica de um caso de mastocitoma cutâneo canino com progressão do grau histológico. Um cão da raça Shar-pei, cinco anos de idade, não castrado, pesando 20 kg, foi encaminhado para atendimento, com histórico de alopecia e prurido crônico, apresentando nódulo localizado em membro pélvico esquerdo. O nódulo foi retirado cirurgicamente e o material foi encaminhado ao exame histopatoló- gico e imunoistoquímico revelando mastocitoma de baixo grau, marcação membranosa de c-kit (KIT I) e proliferação celular (ki-67) menor que 23 células, contadas em cinco campos de grande aumento. Cinco meses após diagnóstico inicial, o animal retornou apresentando nódulo aderido e localizado na ferida cirúrgica. Após diagnóstico de mastocitoma através do exame citológico, iniciou-se quimioterapia objetivando citorredução, no entanto, notou-se crescimento tumoral. Como a tentativa de redução tumoral não foi satisfatória e surgiram novos nódulos, optou-se por realizar retirada cirúrgica. Em nova avaliação histopatológica e imunoistoquímica, verificou-se progressão tumoral, com diagnóstico de mastocitoma de alto grau, marcação citoplasmática de c-kit (KIT III) e proliferação celular (ki-67) maior que 23 células. Após o procedimento cirúrgico, houve recidiva tumoral e iniciou- -se protocolo

Kutani mastocitomi su jedna od najčešći neoplazmi pasa. Vode poreklo iz kostne srži, iz linije opredeljene za mastocite i pokazuju vrlo promenljivo ponašanje, te je predloženo nekoliko kriterijuma za nji ovu klasifikaciju, uključujući istološku gradaciju i markere proliferacije ćelija Citoplazmatska ekspresija CD117 ili KIT proteina (tirozin kinaza receptor) dovodi se u vezu sa višim stepenima maligniteta mastocitoma i lošijom prognozom Dokazano je da postoji veza između aberantne ekspresije CD117 i postojanja c-kit mutacija, iako mutacije često nisu prisutne kod svih mastocitoma sa aberantnom ekspresijom KIT proteina. Ispitivanjima su obu vaćena 24 kutana mastocitoma i 6 kontrolni uzoraka kože od 30 pasa različitog uzrasta, rase i pola. Kao pozitivna kontrola za c-kit mutaciju korišćen je izolat DNK psa sa mastocitomom za koga je ranije utvrđeno da poseduje navedenu mutaciju Uzorci tkiva fiksiranog u formalinu i ukalupljenog u parafinske blokove, bojeni su hematoksilin-eozinom i toluidin blue metodom, a imunohistohemijski na CD117, Ki-67, PCNA i CD45RA. DNK je izolovana iz istih parafinskih blokova, a primenom PCR metode i korišćenjem specifični prajmera PE1 i PE2 amplifikovan je željeni fragment DNK. Četrnaest od 24 mastocitoma su prema istološkim osobinama svrstana u mastocitome visokog stepena maligniteta, dok su preostalih deset, mastocitomi niskog stepena maligniteta. Kod 7 mastocitoma prisutno je više od šest mitotskih figura na 10 polja velikog uvećanja Prisustvo više od dve multinuklearne ćelije na 10 polja velikog uvećanja uočeno je kod 11 mastocitoma, dok su više od dve ćelije sa bizarnim jedrom na 10 polja velikog uvećanja uočene kod 10 mastocitoma. Osam mastocitoma sadrži više od 10% anaplastični mastocita sa jedrima promera oko 8-10 mikrometara. Od ukupno 24 mastocitoma, devet je Ki-67 pozitivno (7 mastocitomima višeg i 2 mastocitomima nižeg stepena maligniteta), dok se ekspresija PCNA i CD45RA uočava kod svih mastocitoma. Devet mastocitoma višeg stepe, Cutaneous mast cell tumours (MCTs) are one of the most common neoplasm in dogs. Originate from the bone marrow, from the mast cells line, but because of its location are being studied within skin tumors. MCTs show a highly variable biologic behavior and therefore several criteria have been proposed for their classification, including histological grading and cell proliferation markers. Cytoplasmic expression of CD117 or KIT protein (tyrosine kinasa receptor) has been found to correlate with higher histological grade and with a worsened prognosis. It has been revealed that there is a conection between the aberrant expression of CD117 and presence of c-kit mutations, although mutations were not present in all mast cell tumors with aberrant expression of KIT protein. Twenty four MCTs and 6 control specimens from 30 dogs of different age, breed and sex were included in this study. DNA isolated from the dog with mast cell tumor which had previously found to has specified mutation was used as a positive control for c-kit mutation. Formalin fixed and paraffin embedded tissue samples were stained with hematoxylin-eosin and toluidin blue and immunohistochemically tested for CD117, Ki-67, PCNA i CD45RA expression. DNA had been extracted from the same paraffin blocks and subsequent polymerase chain reaction amplification was performed using PE1 and PE2 primers. Fourteen of 24 MCTs were histologically high-grade, while ten were classified as a low-grade malignancy. Seven MCTs have more than six mitotic figures in 10 high-power fields. The presence of more than two multinucleated cells in 10 high-power fields was observed in 11 MCTs, while more than two cells with bizarre nuclei in 10 hpf were observed in 10 MCTs. Eight MCTs have more than 10% of neoplastic mast cells with nuclei about 8-10 microns in diameter. Of the total MCTs, 9 tumors are Ki-67 positive (7 mastocytomas of high and 2 mastocytomas of low-grade malignancy), while the expression of PCNA and CD45RA was observed i

Cutaneous mast cell tumours (MCTs) are one of the most common neoplasm in dogs. Originate from the bone marrow, from the mast cells line, but because of its location are being studied within skin tumors. MCTs show a highly variable biologic behavior and therefore several criteria have been proposed for their classification, including histological grading and cell proliferation markers. Cytoplasmic expression of CD117 or KIT protein (tyrosine kinasa receptor) has been found to correlate with higher histological grade and with a worsened prognosis. It has been revealed that there is a conection between the aberrant expression of CD117 and presence of c-kit mutations, although mutations were not present in all mast cell tumors with aberrant expression of KIT protein. Twenty four MCTs and 6 control specimens from 30 dogs of different age, breed and sex were included in this study. DNA isolated from the dog with mast cell tumor which had previously found to has specified mutation was used as a positive control for c-kit mutation. Formalin fixed and paraffin embedded tissue samples were stained with hematoxylin-eosin and toluidin blue and immunohistochemically tested for CD117, Ki-67, PCNA i CD45RA expression. DNA had been extracted from the same paraffin blocks and subsequent polymerase chain reaction amplification was performed using PE1 and PE2 primers. Fourteen of 24 MCTs were histologically high-grade, while ten were classified as a low-grade malignancy. Seven MCTs have more than six mitotic figures in 10 high-power fields. The presence of more than two multinucleated cells in 10 high-power fields was observed in 11 MCTs, while more than two cells with bizarre nuclei in 10 hpf were observed in 10 MCTs. Eight MCTs have more than 10% of neoplastic mast cells with nuclei about 8-10 microns in diameter. Of the total MCTs, 9 tumors are Ki-67 positive (7 mastocytomas of high and 2 mastocytomas of low-grade malignancy), while the expression of PCNA and CD45RA was observed i, Kutani mastocitomi su jedna od najčešći neoplazmi pasa. Vode poreklo iz kostne srži, iz linije opredeljene za mastocite i pokazuju vrlo promenljivo ponašanje, te je predloženo nekoliko kriterijuma za nji ovu klasifikaciju, uključujući istološku gradaciju i markere proliferacije ćelija Citoplazmatska ekspresija CD117 ili KIT proteina (tirozin kinaza receptor) dovodi se u vezu sa višim stepenima maligniteta mastocitoma i lošijom prognozom Dokazano je da postoji veza između aberantne ekspresije CD117 i postojanja c-kit mutacija, iako mutacije često nisu prisutne kod svih mastocitoma sa aberantnom ekspresijom KIT proteina. Ispitivanjima su obu vaćena 24 kutana mastocitoma i 6 kontrolni uzoraka kože od 30 pasa različitog uzrasta, rase i pola. Kao pozitivna kontrola za c-kit mutaciju korišćen je izolat DNK psa sa mastocitomom za koga je ranije utvrđeno da poseduje navedenu mutaciju Uzorci tkiva fiksiranog u formalinu i ukalupljenog u parafinske blokove, bojeni su hematoksilin-eozinom i toluidin blue metodom, a imunohistohemijski na CD117, Ki-67, PCNA i CD45RA. DNK je izolovana iz istih parafinskih blokova, a primenom PCR metode i korišćenjem specifični prajmera PE1 i PE2 amplifikovan je željeni fragment DNK. Četrnaest od 24 mastocitoma su prema istološkim osobinama svrstana u mastocitome visokog stepena maligniteta, dok su preostalih deset, mastocitomi niskog stepena maligniteta. Kod 7 mastocitoma prisutno je više od šest mitotskih figura na 10 polja velikog uvećanja Prisustvo više od dve multinuklearne ćelije na 10 polja velikog uvećanja uočeno je kod 11 mastocitoma, dok su više od dve ćelije sa bizarnim jedrom na 10 polja velikog uvećanja uočene kod 10 mastocitoma. Osam mastocitoma sadrži više od 10% anaplastični mastocita sa jedrima promera oko 8-10 mikrometara. Od ukupno 24 mastocitoma, devet je Ki-67 pozitivno (7 mastocitomima višeg i 2 mastocitomima nižeg stepena maligniteta), dok se ekspresija PCNA i CD45RA uočava kod svih mastocitoma. Devet mastocitoma višeg stepe

Cutaneous mast cell tumours (MCTs) are one of the most common neoplasm in dogs. Originate from the bone marrow, from the mast cells line, but because of its location are being studied within skin tumors. MCTs show a highly variable biologic behavior and therefore several criteria have been proposed for their classification, including histological grading and cell proliferation markers. Cytoplasmic expression of CD117 or KIT protein (tyrosine kinasa receptor) has been found to correlate with higher histological grade and with a worsened prognosis. It has been revealed that there is a conection between the aberrant expression of CD117 and presence of c-kit mutations, although mutations were not present in all mast cell tumors with aberrant expression of KIT protein. Twenty four MCTs and 6 control specimens from 30 dogs of different age, breed and sex were included in this study. DNA isolated from the dog with mast cell tumor which had previously found to has specified mutation was used as a positive control for c-kit mutation. Formalin fixed and paraffin embedded tissue samples were stained with hematoxylin-eosin and toluidin blue and immunohistochemically tested for CD117, Ki-67, PCNA i CD45RA expression. DNA had been extracted from the same paraffin blocks and subsequent polymerase chain reaction amplification was performed using PE1 and PE2 primers. Fourteen of 24 MCTs were histologically high-grade, while ten were classified as a low-grade malignancy. Seven MCTs have more than six mitotic figures in 10 high-power fields. The presence of more than two multinucleated cells in 10 high-power fields was observed in 11 MCTs, while more than two cells with bizarre nuclei in 10 hpf were observed in 10 MCTs. Eight MCTs have more than 10% of neoplastic mast cells with nuclei about 8-10 microns in diameter. Of the total MCTs, 9 tumors are Ki-67 positive (7 mastocytomas of high and 2 mastocytomas of low-grade malignancy), while the expression of PCNA and CD45RA was observed i, Kutani mastocitomi su jedna od najčešći neoplazmi pasa. Vode poreklo iz kostne srži, iz linije opredeljene za mastocite i pokazuju vrlo promenljivo ponašanje, te je predloženo nekoliko kriterijuma za nji ovu klasifikaciju, uključujući istološku gradaciju i markere proliferacije ćelija Citoplazmatska ekspresija CD117 ili KIT proteina (tirozin kinaza receptor) dovodi se u vezu sa višim stepenima maligniteta mastocitoma i lošijom prognozom Dokazano je da postoji veza između aberantne ekspresije CD117 i postojanja c-kit mutacija, iako mutacije često nisu prisutne kod svih mastocitoma sa aberantnom ekspresijom KIT proteina. Ispitivanjima su obu vaćena 24 kutana mastocitoma i 6 kontrolni uzoraka kože od 30 pasa različitog uzrasta, rase i pola. Kao pozitivna kontrola za c-kit mutaciju korišćen je izolat DNK psa sa mastocitomom za koga je ranije utvrđeno da poseduje navedenu mutaciju Uzorci tkiva fiksiranog u formalinu i ukalupljenog u parafinske blokove, bojeni su hematoksilin-eozinom i toluidin blue metodom, a imunohistohemijski na CD117, Ki-67, PCNA i CD45RA. DNK je izolovana iz istih parafinskih blokova, a primenom PCR metode i korišćenjem specifični prajmera PE1 i PE2 amplifikovan je željeni fragment DNK. Četrnaest od 24 mastocitoma su prema istološkim osobinama svrstana u mastocitome visokog stepena maligniteta, dok su preostalih deset, mastocitomi niskog stepena maligniteta. Kod 7 mastocitoma prisutno je više od šest mitotskih figura na 10 polja velikog uvećanja Prisustvo više od dve multinuklearne ćelije na 10 polja velikog uvećanja uočeno je kod 11 mastocitoma, dok su više od dve ćelije sa bizarnim jedrom na 10 polja velikog uvećanja uočene kod 10 mastocitoma. Osam mastocitoma sadrži više od 10% anaplastični mastocita sa jedrima promera oko 8-10 mikrometara. Od ukupno 24 mastocitoma, devet je Ki-67 pozitivno (7 mastocitomima višeg i 2 mastocitomima nižeg stepena maligniteta), dok se ekspresija PCNA i CD45RA uočava kod svih mastocitoma. Devet mastocitoma višeg stepe

A 10-year-old male neutered Boxer presented with recurrence of a mast cell tumor at the right medial canthal area. Following excision including 2 cm margins, the medial one-half of the upper and lower eyelids and the medial canthus were reconstructed using an axial pattern flap based on the cutaneous branch of the superficial temporal artery. The bulbar conjunctiva of the nictitans was preserved and sutured to the medial flap edge, thus creating a conjunctival lining to the deep aspect of the flap, protecting corneal epithelium. This is a valuable surgical technique for closing a large skin defect and reconstructing the medial eyelids, thus preserving the globe.

A 10-year-old male neutered Boxer presented with recurrence of a mast cell tumor at the right medial canthal area. Following excision including 2 cm margins, the medial one-half of the upper and lower eyelids and the medial canthus were reconstructed using an axial pattern flap based on the cutaneous branch of the superficial temporal artery. The bulbar conjunctiva of the nictitans was preserved and sutured to the medial flap edge, thus creating a conjunctival lining to the deep aspect of the flap, protecting corneal epithelium. This is a valuable surgical technique for closing a large skin defect and reconstructing the medial eyelids, thus preserving the globe.