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Eighteen Months Follow Up of Cases of Melanoma Vaccination – Tumour Phenotype and Post Vaccination Inflammatory Reaction
148:1, 2013
ESVP/ECVP Proceedings 2012
65
GASTRIC HELICOBACTER SPP. AND EARLY GASTRIC CARCINOMA IN DOG: COINCIDENCE OR CONSEQUENCE? D.C. Romero and L.R.M. S a Laboratory of Gastroenterology, Department of Pathology, University of S~ao Paulo, Brazil Introduction: Gastric Helicobacter spp. infection has been associated with gastritis, peptic ulcers and gastric tumours in man for many years, but there are few reports describing Helicobacter spp. infection and gastric polyps or carcinomas in domestic dogs. The aim of this report is describe and discuss a case of Helicobacter spp. infection and early gastric carcinoma in a dog. Materials and Methods: A 6-year-old female pit bull terrier died due to coagulopathy and was subjected to necropsy examination. Biopsy samples of stomach were collected and fixed for microscopical analysis. Results: The antrum of the stomach contained a 150 mm diameter white, dome shaped, sessile, soft nodule with a smooth to irregular surface that projected into the gastric lumen. Microscopically, the nodule was characterized by a focus of early gastric tubular carcinoma adjacent to a hyperplastic polyp. The antral mucosa showed a high intensity of spirochetal Helicobacter spp. organisms, which were mixed in the superficial mucus and within the lumina of gastric glands. Conclusions: The gastric nodule was classified on the basis of the WHO classification of animal tumours. More study is necessary to attempt to define the role of Helicobacter spp. infection in the development of gastric lesions of dogs.
VISCERAL MAST CELL TUMOUR WITH HEPATOCELLULAR EMPERIPOLESIS IN A YORKSHIRE TERRIER N. Cuesta-Garcia and C. Lamm Veterinary Diagnostic Services, University of Glasgow, Glasgow, UK Introduction: Emperipolesis is the process of one cell penetrating the cytoplasm of another without damage to either cell. This process is widely described in the human literature, predominantly related to non-neoplastic haematopoietic syndromes, but also in some neoplasms. In animals, it has been described in megakaryocytes engulfing normal or neoplastic haematopoietic cells. Hepatocellular emperipolesis has been described associated with neoplastic lymphocytes in cats. Materials and Methods: An 8-year-old Yorkshire terrier was presented for post-mortem examination. A complete necropsy examination was performed. Selected tissues were fixed in 10% neutral buffered formalin, sectioned and processed routinely for histopathological examination. Results: On gross examination, a multinodular, 6 6 10 cm, white to tan, firm mass was found adherent to the mesentery and adjacent to the small intestine. Mesenteric lymph nodes were markedly enlarged and there were additional small nodules scattered throughout the mesentery. The liver was enlarged with a pebble stone-like surface. On histology, the mass was characterized as a mast cell tumour. Metastatic mast cells were present within the lymph nodes, mesentery and liver. Emperopolesis of neoplastic mast cells was evident in numerous hepatocytes. Conclusions: Neoplastic mast cells have been described to invade the cytoplasm of epithelial cells (epitheliotropism) in a cat. However, to the author’s knowledge, this is the first case documenting hepatocellular emperipolesis of neoplastic mast cells in a dog.
MAST CELLS AND THEIR RELATIONSHIP TO ANGIOGENESIS AND PROGNOSIS IN CANINE MELANOCYTIC TUMOURS M. Cuiti~ no, N. Guido, A. Massone and J. Idiart University of La Plata, Argentina Introduction: It has been suggested that mast cells play a role in tumour progression through different mechanisms such as promoting angiogenesis. To date, only one study has analyzed the role of mast cells in angiogenesis and prognosis in canine melanocytic tumours (MTs). Materials and Methods: A total of 30 cutaneous and 16 oral MTs were stained with toluidine blue and mast cell density (MCD) was determined within the tumour and at the tumour periphery. Microvessel density (MVD) was determined by immunohistochemistry. Results: MCD and MVD were not correlated in either cutaneous or oral MTs. In cutaneous MTs, mean MCD was 37 8 (SE) in dogs that were alive at 1 year post diagnosis and 16 4 (SE) in dogs that died within 1 year of diagnosis (P 5 0.635). In oral MTs, mean MCD was 12 5 (SE) in dogs alive at 1 year post diagnosis and 37 25 (SE) in dogs that died within 1 year of diagnosis (P 5 0.706). MCD at the tumour periphery was higher than MCD within the tumour, but it did not differ significantly between the survival groups in either cutaneous or oral MTs (45 9 versus 45 14; P 5 0.970 and 53 16 versus 32 11; P 5 0.280, respectively). Conclusions: According to these results, mast cells in canine MTs are not clearly related to angiogenesis and they seem to have no prognostic significance for these tumours.
EIGHTEEN MONTHS FOLLOW UP OF CASES OF MELANOMA VACCINATION e TUMOUR PHENOTYPE AND POST VACCINATION INFLAMMATORY REACTION ujo x, J. Henriques *,y, R. Felisberto *, P. Faısca y,z, M. Ara T. Carvalho { and M. Peleteiro# *Oncovet, Lisbon, yCentre for Research in Veterinary Sciences (CICV)/ FMV e ULHT, Lisbon, zDNAtech, Lisbon, xINNO, Braga, {VETPAT, Lisbon and #Interdisciplinary Research Centre on Animal Health, (CIISA)/ FMV/UTL, Lisbon, Portugal Introduction: A DNA-based vaccine for canine melanoma was developed by Merial, USA. It contains a gene encoding human tyrosinase, which stimulates an immune response against canine tyrosinase in melanoma cells. The follow up of various vaccinated animals has been accomplished. Materials and Methods: A total of 14 dogs and one cat were vaccinated, 11 of which received the full first stage treatment of four doses of the product. Immunohistochemistry for melan A was performed in 12 cases. For lesions that developed after the end of the vaccination, lymphocyte markers (CD3 and Pax5) were also evaluated. Results: Five out of the 14 dogs died, three due to causes unrelated to the melanoma. Seven of the survivors developed lymph node metastases, but the disease did not progress further. Most tumours were amelanotic melanomas, 80% oral and 20% digital. Marking with melan A was variable, but never strong in the cases of lower overall survival. In biopsy samples of the lesions that developed after vaccination in one dog, T lymphocytes were much more numerous than B cells. Conclusions: The degree of melan A marking may have a role in predicting the response of melanomas to immunotherapy and mobilization of T cells appears to be important in recurring lesions after vaccination.
ESVP/ECVP Proceedings 2012
65
GASTRIC HELICOBACTER SPP. AND EARLY GASTRIC CARCINOMA IN DOG: COINCIDENCE OR CONSEQUENCE? D.C. Romero and L.R.M. S a Laboratory of Gastroenterology, Department of Pathology, University of S~ao Paulo, Brazil Introduction: Gastric Helicobacter spp. infection has been associated with gastritis, peptic ulcers and gastric tumours in man for many years, but there are few reports describing Helicobacter spp. infection and gastric polyps or carcinomas in domestic dogs. The aim of this report is describe and discuss a case of Helicobacter spp. infection and early gastric carcinoma in a dog. Materials and Methods: A 6-year-old female pit bull terrier died due to coagulopathy and was subjected to necropsy examination. Biopsy samples of stomach were collected and fixed for microscopical analysis. Results: The antrum of the stomach contained a 150 mm diameter white, dome shaped, sessile, soft nodule with a smooth to irregular surface that projected into the gastric lumen. Microscopically, the nodule was characterized by a focus of early gastric tubular carcinoma adjacent to a hyperplastic polyp. The antral mucosa showed a high intensity of spirochetal Helicobacter spp. organisms, which were mixed in the superficial mucus and within the lumina of gastric glands. Conclusions: The gastric nodule was classified on the basis of the WHO classification of animal tumours. More study is necessary to attempt to define the role of Helicobacter spp. infection in the development of gastric lesions of dogs.
VISCERAL MAST CELL TUMOUR WITH HEPATOCELLULAR EMPERIPOLESIS IN A YORKSHIRE TERRIER N. Cuesta-Garcia and C. Lamm Veterinary Diagnostic Services, University of Glasgow, Glasgow, UK Introduction: Emperipolesis is the process of one cell penetrating the cytoplasm of another without damage to either cell. This process is widely described in the human literature, predominantly related to non-neoplastic haematopoietic syndromes, but also in some neoplasms. In animals, it has been described in megakaryocytes engulfing normal or neoplastic haematopoietic cells. Hepatocellular emperipolesis has been described associated with neoplastic lymphocytes in cats. Materials and Methods: An 8-year-old Yorkshire terrier was presented for post-mortem examination. A complete necropsy examination was performed. Selected tissues were fixed in 10% neutral buffered formalin, sectioned and processed routinely for histopathological examination. Results: On gross examination, a multinodular, 6 6 10 cm, white to tan, firm mass was found adherent to the mesentery and adjacent to the small intestine. Mesenteric lymph nodes were markedly enlarged and there were additional small nodules scattered throughout the mesentery. The liver was enlarged with a pebble stone-like surface. On histology, the mass was characterized as a mast cell tumour. Metastatic mast cells were present within the lymph nodes, mesentery and liver. Emperopolesis of neoplastic mast cells was evident in numerous hepatocytes. Conclusions: Neoplastic mast cells have been described to invade the cytoplasm of epithelial cells (epitheliotropism) in a cat. However, to the author’s knowledge, this is the first case documenting hepatocellular emperipolesis of neoplastic mast cells in a dog.
MAST CELLS AND THEIR RELATIONSHIP TO ANGIOGENESIS AND PROGNOSIS IN CANINE MELANOCYTIC TUMOURS M. Cuiti~ no, N. Guido, A. Massone and J. Idiart University of La Plata, Argentina Introduction: It has been suggested that mast cells play a role in tumour progression through different mechanisms such as promoting angiogenesis. To date, only one study has analyzed the role of mast cells in angiogenesis and prognosis in canine melanocytic tumours (MTs). Materials and Methods: A total of 30 cutaneous and 16 oral MTs were stained with toluidine blue and mast cell density (MCD) was determined within the tumour and at the tumour periphery. Microvessel density (MVD) was determined by immunohistochemistry. Results: MCD and MVD were not correlated in either cutaneous or oral MTs. In cutaneous MTs, mean MCD was 37 8 (SE) in dogs that were alive at 1 year post diagnosis and 16 4 (SE) in dogs that died within 1 year of diagnosis (P 5 0.635). In oral MTs, mean MCD was 12 5 (SE) in dogs alive at 1 year post diagnosis and 37 25 (SE) in dogs that died within 1 year of diagnosis (P 5 0.706). MCD at the tumour periphery was higher than MCD within the tumour, but it did not differ significantly between the survival groups in either cutaneous or oral MTs (45 9 versus 45 14; P 5 0.970 and 53 16 versus 32 11; P 5 0.280, respectively). Conclusions: According to these results, mast cells in canine MTs are not clearly related to angiogenesis and they seem to have no prognostic significance for these tumours.
EIGHTEEN MONTHS FOLLOW UP OF CASES OF MELANOMA VACCINATION e TUMOUR PHENOTYPE AND POST VACCINATION INFLAMMATORY REACTION ujo x, J. Henriques *,y, R. Felisberto *, P. Faısca y,z, M. Ara T. Carvalho { and M. Peleteiro# *Oncovet, Lisbon, yCentre for Research in Veterinary Sciences (CICV)/ FMV e ULHT, Lisbon, zDNAtech, Lisbon, xINNO, Braga, {VETPAT, Lisbon and #Interdisciplinary Research Centre on Animal Health, (CIISA)/ FMV/UTL, Lisbon, Portugal Introduction: A DNA-based vaccine for canine melanoma was developed by Merial, USA. It contains a gene encoding human tyrosinase, which stimulates an immune response against canine tyrosinase in melanoma cells. The follow up of various vaccinated animals has been accomplished. Materials and Methods: A total of 14 dogs and one cat were vaccinated, 11 of which received the full first stage treatment of four doses of the product. Immunohistochemistry for melan A was performed in 12 cases. For lesions that developed after the end of the vaccination, lymphocyte markers (CD3 and Pax5) were also evaluated. Results: Five out of the 14 dogs died, three due to causes unrelated to the melanoma. Seven of the survivors developed lymph node metastases, but the disease did not progress further. Most tumours were amelanotic melanomas, 80% oral and 20% digital. Marking with melan A was variable, but never strong in the cases of lower overall survival. In biopsy samples of the lesions that developed after vaccination in one dog, T lymphocytes were much more numerous than B cells. Conclusions: The degree of melan A marking may have a role in predicting the response of melanomas to immunotherapy and mobilization of T cells appears to be important in recurring lesions after vaccination.