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Collision tumour in a domestic shorthair CAT
64
ESVP/ECVP Proceedings 2012
EXPRESSION OF VIMENTIN AND MINICHROMOSOME MAINTENANCE PROTEIN 3 (MCM3) IN CANINE AND HUMAN LEYDIG CELL TUMOURS: A COMPARATIVE STUDY R. Ciaputa *, M. Kandefer-Gola *, I. Janus *, M. Nowak *, J.A. Madej *, D. Poradowski y, B. Obmin0 ska-Mrukowicz y and E. G orzyn0 skaz *Department of Pathology, Division of Pathomorphology and Veterinary Forensics, y Department of Biochemistry, Pharmacology and Toxicology, Division of Pharmacology and Toxicology, University of Environmental and Life Sciences, Wroclaw and zHistopathological Laboratory ‘Hist-Med’, Wroclaw, Poland Introduction: Testicular tumours in man and dogs are not uncommon. According to the WHO classification, tumours of Leydig cells in dogs are considered to be one of the most frequent. The aim of this study was to demonstrate the expression of vimentin to determine the mesenchymal origin of the tumour and MCM3, a supportive protein in the assessment of cell proliferation, and to compare the expression of these markers in testicular tumours in dogs and men. Materials and Methods: Tumours from dogs (n 5 40) and men (n 5 10) from archival collections were subjected to immunohistochemistry using the antibodies specific for vimentin (clone Vim 3B4, DAKO) and MCM3 (clone 101, DAKO). Results: Vimentin was expressed in 85% of Leydig cell tumours with strong cytoplasmic labelling and was expressed in 15% of the tumours with moderate cytoplasmic labelling. MCM3 (nuclear expression) was expressed at moderate level in 90% of the human tumours and was expressed weakly in 10% of the samples. In canine tumours, MCM3 was expressed moderately in 85% and strongly in 15% of cases. Conclusions: The results of this study increases knowledge of the biological behaviour of these proteins in dogs and indicates their usefulness as diagnostic markers for testicular cancer in men and dogs. EXPRESSION OF MINI-CHROMOSOME MAINTENANCE PROTEIN 7 (MCM7) IN A POORLY-DIFFERENTIATED CANINE PROSTATE TUMOUR R. Ciaputa *, M. Kandefer-Gola *, I. Janus *, M. Nowak *, J.A. Madej *, S. Dzimira *, D. Poradowski y and B. Obmin0 skaMrukowiczy *Department of Pathology, Division of Pathomorphology and Veterinary Forensic and yDepartment of Biochemistry, Pharmacology and Toxicology, Division of Pharmacology and Toxicology, University of Environmental and Life Sciences, Wroclaw, Poland Introduction: Neoplastic lesions of the prostate are most common in dogs aged 10 years or older. Dogs are a useful animal model for examination of factors affecting the initiation and progression of prostate cancer because they live in the same environment as man. According to the World Health Organisation (WHO), prostate cancer in domestic animals is divided into adenocarcinoma and a poorly-differentiated cancer. The aim of this study was to determine the expression of the MCM7 cell proliferation marker, which is present in all phases of cell division and disappears only in the G phase. Materials and Methods: Sections of prostate tumours (n 5 5 cases) were subjected to immunohistochemistry with antibody specific for minichromosome maintenance protein 7 (MCM7) (clone DCS141.1, NOVOCASTRA). The expression of MCM7 was assessed on the basis of the percentage of positively labelled nuclei. Results: The expression of MCM7 in the cells of canine poorly-differentiated prostate cancer was high in all cases (70e85% of cells showing a positive nuclear reaction). Conclusions: The results suggest a high mitotic potential for this type of cancer and confirmed the usefulness of MCM 7 in the diagnosis of prostate cancer in dogs. COMPARISON OF CELL PROLIFERATION MARKERS IN CANINE FIBROSARCOMAS M. Kandefer-Gola *, R. Ciaputa *, S. Dzimira *, I. Janus *, J.A. Madej *, M. Nowak * and D. Poradowskiy *Department of Pathology, Division of Pathomorphology and Veterinary Forensics and yDepartment of Biochemistry, Pharmacology and Toxicology, Division of Pharmacology and Toxicology, University of Environmental and Life Sciences, Wroclaw, Poland
152:1, 2015
Introduction: Fibrosarcoma is a malignant neoplasm originating from mesenchymal tissue. The most commonly used cell proliferation markers are Ki67 and PCNA, whose presence can be detected in all phases of cell division. PCNA can also be detected during the DNA repair processes and after mitosis is complete. TP53 protein is responsible for cell division and regulation of apoptosis. The MCM-protein group initiates DNA duplication. Materials and Methods: Twenty canine fibrosarcomas were subjected to immunohistochemistry for detection of Ki67 (clone MIB1, Dako); PCNA (clone PC10, Dako); TP53 (clone 318-611, Dako) and MCM-3 (clone 101, Novocastra). Cell marker expression was evaluated using a semiquantitative scale. Results: Ki67 expression was scored in 65% of cases at the level of ++, in 25% of cases at +++ and in 10% of cases at +. Similar results were obtained for MCM-3 expression: 75% ++, 20% +++ and 5% +. PCNA expression in 85% of cases was at the level of +++ and in 15% was scored as ++. TP53 expression in 65% of cases was at the level of ++, in 15% of cases at + and there was no reaction in 20% of cases. Conclusions: Due to the high general expression level of PCNA and lack of TP53 expression in 20% of the tumours, these proteins may not be useful diagnostic markers in canine fibrosarcoma. IMMUNOHISTOCHEMICAL DETECTION OF CD25+ LYMPHOCYTES IN FELINE INJECTION SITE SARCOMA AND POST-INJECTION PANNICULITIS G.E. Magi, M. Petini, S. Berardi and G. Rossi School of Bioscience and Veterinary Medicine, University of Camerino, Italy Introduction: CD25 is the a-subunit of the membrane-bound interleukin-2 receptor, which is mainly expressed by regulatory T cells (Tregs). Normally these cells regulate immune system activity and prevent autoimmunity. Imbalanced function or number of Tregs, either enhanced or decreased, might lead to tumour development and autoimmunity, respectively. In the present study we hypothesized the presence of CD25+ cells among tumour infiltrating lymphocytes (TILs) that are normally associated with feline injection site sarcoma (FISS). To this end we analyzed CD25 protein expression by immunohistochemistry in 18 cases of FISS and in 15 cases of post-injection panniculitis (PIP). Materials and Methods: Sections (4 mm) were immunolabelled using the avidinebiotin technique for CD25 (MAb). Labelling was evaluated semiquantitatively for percentage of positivity (10 fields at 40) and the expression was considered as: percentage !20%, weak positivity; 21e50%, moderate positivity; O50%, strong positivity. Results: All FISS specimens and 14 of 15 PIP specimens had lymphocytes positive for CD25. The immunolabelling appeared as distinct membrane or diffuse cytoplasmic expression. Nine cases of FISS strongly expressed CD25; the median expression percentage for all 18 cases was 55%. Six cases of PIP had strong positivity, with a median expression percentage for all the cases of 41%. Conclusions: The present study identified large numbers of CD25+ cells among TILs and in the lesions of panniculitis. CD25+ lymphocytes inhibit Th1 and CD8+ immune responses and consequently they could represent a permissive and stimulatory factor for tumour development. COLLISION TUMOUR IN A DOMESTIC SHORTHAIR CAT K. Siudak, M. Reinacher and M. Henrich Institute for Veterinary-Pathology, Justus-Liebig-University Giessen, Giessen, Germany Introduction: Collision tumours are rare and are composed of two or more independent neoplasms. In this case a collision tumour of a fibrosarcoma and a lymphoma in a cat is described. Materials and Methods: A 12-year-old cat was presented with a tumour on the right thoracic wall, covered by haired skin and measuring 5 cm in diameter. Due to the location, age and species the clinician suspected a fibrosarcoma. The tumour was removed surgically and sent to the Institute for Veterinary-Pathology, Giessen, Germany, for a pathological examination. Results: The tumour was composed of two components: a spindle cell component growing in interlacing streams and bundles and a
152:1, 2015
ESVP/ECVP Proceedings 2012
population of neoplastic blastoid round cells. Without any definable demarcation both populations of neoplastic cells infiltrated into each other, giving rise to a collision zone displaying small foci of round cells adjacent to bundles of neoplastic spindle cells. Additionally, infiltrating reactive lymphocytes, areas of necrosis and dystrophic calcification were present within this zone. Immunohistology identified the round cell component as T cells, while the spindle cell component was positive for vimentin and negative for markers of peripheral nerve sheet tumours and myocytes. Conclusions: Fibrosarcomas and lymphomas are common in cats. Although the chance of a concurrent occurrence of both tumour types in the same location is very low, the possibility has to be taken into account by the pathologist, particularly with regard to the different biological behaviour and prognosis of these two entities. THREE DIFFERENT MALIGNANCIES IN A CAT C. H ard af Segerstad, E. Karlstam and K. Bernodt National Veterinary Institute (SVA), Uppsala, Sweden Introduction: A 10-year-old, obese, 9.4 kg, male Norwegian forest cat showed anaemia and pain in the left stifle area. The cat was serologically negative for FeLV and FIV. The cat was anaesthetized to obtain diagnostic biopsy samples. It died the morning after surgery. Materials and Methods: The cat was submitted for necropsy examination. Results: The cat was obese. The spleen was markedly enlarged (20 3e4 cm) with a firm texture. The liver had a few small light-coloured foci. One half of the right kidney was enlarged and had a friable texture. Approximately 15 cm of the small intestine had a markedly thickened wall, with friable texture. The mesenteric lymph node was enlarged. There was a small, irregular lytic area in the left proximal tibia. Microscopically, marked infiltration of neoplastic lymphocytes was seen in the kidney, lymph nodes, bone marrow and intestine. The spleen was markedly scirrhous with scattered foci of irregular cysts, which were delineated by malignant squamous epithelial cells that were acantholytic and occasionally necrotic. Neoplastic acantholytic squamous epithelium was also found in the proximal tibia, invading the bone. The spleen also had several foci of fatty tissue with myelopoietic activity. In the liver there were multiple foci of malignant bile duct epithelium. Conclusions: The finding of three different malignant tumours in a cat is rare. The primary squamous cell tumour was not found and the clinical history of this cat was not fully available. FELINE COCCYGEAL TERATOMA: IMMUNOHISTOCHEMICAL CHARACTERIZATION OF MATURE AND IMMATURE TISSUE COMPONENTS a rtner * and P. Wohlsein* K. Kegler *, B. Kr€ oner y, W. Baumg€ *Department of Pathology, University of Veterinary Medicine, Hannover and y Tierarztpraxis B. Kr€oner, Kaltenkirchen, Germany Introduction: Congenital teratomas arising in the coccygeal region are not documented in domestic animals. This report describes a congenital coccygeal teratoma in which mature and immature cells and the expression of Sox2, a regulator of stem cell proliferation and differentiation was traced. Materials and Methods: A 6-month-old male Burmese cat presented with a mass ventral to the 5the7th caudal vertebrae. The mass was present at birth, was excised surgically and fixed in 10% neutral buffered formalin. Samples were processed for histopathology and immunohistochemistry. Primary antibodies against vimentin, pan-neurofilament, p75NTR, Sox2, GFAP, periaxin and cytokeratins were used. Results: Histologically, the tumour was composed of derivatives of all three primordial germ layers with neuroectodermal predominance, mainly neural crest differentiation. Double immunolabelling identified Sox2-positive cells co-expressing the neural crest stem cell markers vimentin and p75NTR. An overlapping expression of vimentin-negative and Sox2-, p75NTR-positive cells and GFAP- and p75NTR-positive cells indicated a transition phase from immature to mature non-myelinating Schwann cells (SCs). Periaxin-positive myelinating SCs surrounding neurofilament-positive axons were observed. Sox2 was additionally expressed in immature odontogenic epithelium and cells of endodermal origin. Sox2 was observed in mature satellite glial cells and mucous glands.
65
Conclusions: This case represents a unique teratoma localized to the coccygeal region of a cat. Sox2 was found in immature SCs and in immature odontogenic and endodermally-derived epithelium. However, Sox2 alone is not a specific marker of immaturity, as it was detected in mature non-myelinating SCs, mucous glands and satellite glial cells. Thus, colocalization of Sox2 with other cell markers is necessary for accurate identification. THE VALUE OF CYTOLOGICAL EXAMINATION OF CANINE MAMMARY TUMOURS I. Dolka *, A. Gruk-Jurka y, R. Sapierzyn0 ski *, P. Jurka y and D. qukasz* *Department of Pathology and Veterinary Diagnostics and yDepartment of Small Animal Diseases with Clinics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Poland Introduction: Canine mammary tumours (CMTs) include a variety of histopathological forms and therefore their cytological diagnosis can be challenging. The aim of this study was to determine the accuracy of diagnostic cytology by comparison with histopathology of CMTs and to examine the correlation between cytology and clinical findings and postoperative outcome. Materials and Methods: Twenty-seven samples were obtained by fine needle aspiration (FNA) or tissue imprints for cytopathological examination (CP). These samples were stained by Giemsa. Histopathological examination (HP) was performed by evaluating HEstained sections. Histological and cytological grading was evaluated. Results: CP-HP accuracy for malignant and benign CMTs was obtained in 23/27 cases (85.2%). The sensitivity and specificity of CP was 83.3% and 100%, respectively. A p CP-HP correlation for tumour types occurred in 19/27 (70.4%) samples. The cytological grading and typing correlated with histological assessment. Diagnosis on cytological examination was not associated with clinical findings, overall survival (OS), but with a cause of death due to CMTs. Additionally, malignant, simple types of carcinomas (in cytology) tended to be associated with decreased OS. Shorter OS was significantly associated with tumour metastases and cause of death due to CMT. Conclusions: CP is a valuable diagnostic tool in differentiating between benign and malignant mammary lesions and in obtaining a pre-operative diagnosis. Cytological features of CMTs may predict histological grade. However, CP may not provide valuable prognostic information concerning overall survival in CMT patients. THE PRESENCE OF SHORT FORM OF RON/STK TRANSCRIPT COULD BE A PREDICTOR OF POOR OUTCOME IN FELINE MAMMARY CARCINOMAS L. Maniscalco *, S. Guil-Luna y, S. Iussich *, F. Gattino *, Y. Millan y, J. Martın de Las Mulas y and R. De Maria* *Department of Veterinary Sciences, University of Turin, Italy and y Department of Anatomy and Comparative Anatomical Pathology, University of Cordoba, Spain Introduction: RON/stk tyrosine kinase receptor, identified in the cat as feline-stk, is activated by MSP and overexpressed in human breast cancer. The human RON gene is able to generate respectively the full length (fl) and the short forms (sf) of the transcripts. sf-RON is generated from an alternative transcriptional start from a second promoter within intron 10, which preserves the kinase activity of the receptor. The aim of this research was to investigate the expression of both RON and MST and to identify the presence of the sf-RON transcript in feline mammary carcinomas (FMCs) in relation to clinicopathological findings. Materials and Methods: Immunohistochemical expression of RON and MSP was evaluated on 50 FMCs. To detect sf-RON, RNA was extracted from 47 FMCs and RT-PCR, with primers annealing on exons 10 and 11, was performed on cDNA. Results: Immunohistochemical expression of RON and MSP was observed in 68% and 58% of FMCs, respectively, while 52% of the cases co-expressed both proteins. Expression of RON, MSP or both in FMCs was not correlated with clinical outcome. Feline sf-RON was detected in 27/47 FMCs and was significantly associated with poorly differentiated histological grade. Queens with FMC showing
ESVP/ECVP Proceedings 2012
EXPRESSION OF VIMENTIN AND MINICHROMOSOME MAINTENANCE PROTEIN 3 (MCM3) IN CANINE AND HUMAN LEYDIG CELL TUMOURS: A COMPARATIVE STUDY R. Ciaputa *, M. Kandefer-Gola *, I. Janus *, M. Nowak *, J.A. Madej *, D. Poradowski y, B. Obmin0 ska-Mrukowicz y and E. G orzyn0 skaz *Department of Pathology, Division of Pathomorphology and Veterinary Forensics, y Department of Biochemistry, Pharmacology and Toxicology, Division of Pharmacology and Toxicology, University of Environmental and Life Sciences, Wroclaw and zHistopathological Laboratory ‘Hist-Med’, Wroclaw, Poland Introduction: Testicular tumours in man and dogs are not uncommon. According to the WHO classification, tumours of Leydig cells in dogs are considered to be one of the most frequent. The aim of this study was to demonstrate the expression of vimentin to determine the mesenchymal origin of the tumour and MCM3, a supportive protein in the assessment of cell proliferation, and to compare the expression of these markers in testicular tumours in dogs and men. Materials and Methods: Tumours from dogs (n 5 40) and men (n 5 10) from archival collections were subjected to immunohistochemistry using the antibodies specific for vimentin (clone Vim 3B4, DAKO) and MCM3 (clone 101, DAKO). Results: Vimentin was expressed in 85% of Leydig cell tumours with strong cytoplasmic labelling and was expressed in 15% of the tumours with moderate cytoplasmic labelling. MCM3 (nuclear expression) was expressed at moderate level in 90% of the human tumours and was expressed weakly in 10% of the samples. In canine tumours, MCM3 was expressed moderately in 85% and strongly in 15% of cases. Conclusions: The results of this study increases knowledge of the biological behaviour of these proteins in dogs and indicates their usefulness as diagnostic markers for testicular cancer in men and dogs. EXPRESSION OF MINI-CHROMOSOME MAINTENANCE PROTEIN 7 (MCM7) IN A POORLY-DIFFERENTIATED CANINE PROSTATE TUMOUR R. Ciaputa *, M. Kandefer-Gola *, I. Janus *, M. Nowak *, J.A. Madej *, S. Dzimira *, D. Poradowski y and B. Obmin0 skaMrukowiczy *Department of Pathology, Division of Pathomorphology and Veterinary Forensic and yDepartment of Biochemistry, Pharmacology and Toxicology, Division of Pharmacology and Toxicology, University of Environmental and Life Sciences, Wroclaw, Poland Introduction: Neoplastic lesions of the prostate are most common in dogs aged 10 years or older. Dogs are a useful animal model for examination of factors affecting the initiation and progression of prostate cancer because they live in the same environment as man. According to the World Health Organisation (WHO), prostate cancer in domestic animals is divided into adenocarcinoma and a poorly-differentiated cancer. The aim of this study was to determine the expression of the MCM7 cell proliferation marker, which is present in all phases of cell division and disappears only in the G phase. Materials and Methods: Sections of prostate tumours (n 5 5 cases) were subjected to immunohistochemistry with antibody specific for minichromosome maintenance protein 7 (MCM7) (clone DCS141.1, NOVOCASTRA). The expression of MCM7 was assessed on the basis of the percentage of positively labelled nuclei. Results: The expression of MCM7 in the cells of canine poorly-differentiated prostate cancer was high in all cases (70e85% of cells showing a positive nuclear reaction). Conclusions: The results suggest a high mitotic potential for this type of cancer and confirmed the usefulness of MCM 7 in the diagnosis of prostate cancer in dogs. COMPARISON OF CELL PROLIFERATION MARKERS IN CANINE FIBROSARCOMAS M. Kandefer-Gola *, R. Ciaputa *, S. Dzimira *, I. Janus *, J.A. Madej *, M. Nowak * and D. Poradowskiy *Department of Pathology, Division of Pathomorphology and Veterinary Forensics and yDepartment of Biochemistry, Pharmacology and Toxicology, Division of Pharmacology and Toxicology, University of Environmental and Life Sciences, Wroclaw, Poland
152:1, 2015
Introduction: Fibrosarcoma is a malignant neoplasm originating from mesenchymal tissue. The most commonly used cell proliferation markers are Ki67 and PCNA, whose presence can be detected in all phases of cell division. PCNA can also be detected during the DNA repair processes and after mitosis is complete. TP53 protein is responsible for cell division and regulation of apoptosis. The MCM-protein group initiates DNA duplication. Materials and Methods: Twenty canine fibrosarcomas were subjected to immunohistochemistry for detection of Ki67 (clone MIB1, Dako); PCNA (clone PC10, Dako); TP53 (clone 318-611, Dako) and MCM-3 (clone 101, Novocastra). Cell marker expression was evaluated using a semiquantitative scale. Results: Ki67 expression was scored in 65% of cases at the level of ++, in 25% of cases at +++ and in 10% of cases at +. Similar results were obtained for MCM-3 expression: 75% ++, 20% +++ and 5% +. PCNA expression in 85% of cases was at the level of +++ and in 15% was scored as ++. TP53 expression in 65% of cases was at the level of ++, in 15% of cases at + and there was no reaction in 20% of cases. Conclusions: Due to the high general expression level of PCNA and lack of TP53 expression in 20% of the tumours, these proteins may not be useful diagnostic markers in canine fibrosarcoma. IMMUNOHISTOCHEMICAL DETECTION OF CD25+ LYMPHOCYTES IN FELINE INJECTION SITE SARCOMA AND POST-INJECTION PANNICULITIS G.E. Magi, M. Petini, S. Berardi and G. Rossi School of Bioscience and Veterinary Medicine, University of Camerino, Italy Introduction: CD25 is the a-subunit of the membrane-bound interleukin-2 receptor, which is mainly expressed by regulatory T cells (Tregs). Normally these cells regulate immune system activity and prevent autoimmunity. Imbalanced function or number of Tregs, either enhanced or decreased, might lead to tumour development and autoimmunity, respectively. In the present study we hypothesized the presence of CD25+ cells among tumour infiltrating lymphocytes (TILs) that are normally associated with feline injection site sarcoma (FISS). To this end we analyzed CD25 protein expression by immunohistochemistry in 18 cases of FISS and in 15 cases of post-injection panniculitis (PIP). Materials and Methods: Sections (4 mm) were immunolabelled using the avidinebiotin technique for CD25 (MAb). Labelling was evaluated semiquantitatively for percentage of positivity (10 fields at 40) and the expression was considered as: percentage !20%, weak positivity; 21e50%, moderate positivity; O50%, strong positivity. Results: All FISS specimens and 14 of 15 PIP specimens had lymphocytes positive for CD25. The immunolabelling appeared as distinct membrane or diffuse cytoplasmic expression. Nine cases of FISS strongly expressed CD25; the median expression percentage for all 18 cases was 55%. Six cases of PIP had strong positivity, with a median expression percentage for all the cases of 41%. Conclusions: The present study identified large numbers of CD25+ cells among TILs and in the lesions of panniculitis. CD25+ lymphocytes inhibit Th1 and CD8+ immune responses and consequently they could represent a permissive and stimulatory factor for tumour development. COLLISION TUMOUR IN A DOMESTIC SHORTHAIR CAT K. Siudak, M. Reinacher and M. Henrich Institute for Veterinary-Pathology, Justus-Liebig-University Giessen, Giessen, Germany Introduction: Collision tumours are rare and are composed of two or more independent neoplasms. In this case a collision tumour of a fibrosarcoma and a lymphoma in a cat is described. Materials and Methods: A 12-year-old cat was presented with a tumour on the right thoracic wall, covered by haired skin and measuring 5 cm in diameter. Due to the location, age and species the clinician suspected a fibrosarcoma. The tumour was removed surgically and sent to the Institute for Veterinary-Pathology, Giessen, Germany, for a pathological examination. Results: The tumour was composed of two components: a spindle cell component growing in interlacing streams and bundles and a
152:1, 2015
ESVP/ECVP Proceedings 2012
population of neoplastic blastoid round cells. Without any definable demarcation both populations of neoplastic cells infiltrated into each other, giving rise to a collision zone displaying small foci of round cells adjacent to bundles of neoplastic spindle cells. Additionally, infiltrating reactive lymphocytes, areas of necrosis and dystrophic calcification were present within this zone. Immunohistology identified the round cell component as T cells, while the spindle cell component was positive for vimentin and negative for markers of peripheral nerve sheet tumours and myocytes. Conclusions: Fibrosarcomas and lymphomas are common in cats. Although the chance of a concurrent occurrence of both tumour types in the same location is very low, the possibility has to be taken into account by the pathologist, particularly with regard to the different biological behaviour and prognosis of these two entities. THREE DIFFERENT MALIGNANCIES IN A CAT C. H ard af Segerstad, E. Karlstam and K. Bernodt National Veterinary Institute (SVA), Uppsala, Sweden Introduction: A 10-year-old, obese, 9.4 kg, male Norwegian forest cat showed anaemia and pain in the left stifle area. The cat was serologically negative for FeLV and FIV. The cat was anaesthetized to obtain diagnostic biopsy samples. It died the morning after surgery. Materials and Methods: The cat was submitted for necropsy examination. Results: The cat was obese. The spleen was markedly enlarged (20 3e4 cm) with a firm texture. The liver had a few small light-coloured foci. One half of the right kidney was enlarged and had a friable texture. Approximately 15 cm of the small intestine had a markedly thickened wall, with friable texture. The mesenteric lymph node was enlarged. There was a small, irregular lytic area in the left proximal tibia. Microscopically, marked infiltration of neoplastic lymphocytes was seen in the kidney, lymph nodes, bone marrow and intestine. The spleen was markedly scirrhous with scattered foci of irregular cysts, which were delineated by malignant squamous epithelial cells that were acantholytic and occasionally necrotic. Neoplastic acantholytic squamous epithelium was also found in the proximal tibia, invading the bone. The spleen also had several foci of fatty tissue with myelopoietic activity. In the liver there were multiple foci of malignant bile duct epithelium. Conclusions: The finding of three different malignant tumours in a cat is rare. The primary squamous cell tumour was not found and the clinical history of this cat was not fully available. FELINE COCCYGEAL TERATOMA: IMMUNOHISTOCHEMICAL CHARACTERIZATION OF MATURE AND IMMATURE TISSUE COMPONENTS a rtner * and P. Wohlsein* K. Kegler *, B. Kr€ oner y, W. Baumg€ *Department of Pathology, University of Veterinary Medicine, Hannover and y Tierarztpraxis B. Kr€oner, Kaltenkirchen, Germany Introduction: Congenital teratomas arising in the coccygeal region are not documented in domestic animals. This report describes a congenital coccygeal teratoma in which mature and immature cells and the expression of Sox2, a regulator of stem cell proliferation and differentiation was traced. Materials and Methods: A 6-month-old male Burmese cat presented with a mass ventral to the 5the7th caudal vertebrae. The mass was present at birth, was excised surgically and fixed in 10% neutral buffered formalin. Samples were processed for histopathology and immunohistochemistry. Primary antibodies against vimentin, pan-neurofilament, p75NTR, Sox2, GFAP, periaxin and cytokeratins were used. Results: Histologically, the tumour was composed of derivatives of all three primordial germ layers with neuroectodermal predominance, mainly neural crest differentiation. Double immunolabelling identified Sox2-positive cells co-expressing the neural crest stem cell markers vimentin and p75NTR. An overlapping expression of vimentin-negative and Sox2-, p75NTR-positive cells and GFAP- and p75NTR-positive cells indicated a transition phase from immature to mature non-myelinating Schwann cells (SCs). Periaxin-positive myelinating SCs surrounding neurofilament-positive axons were observed. Sox2 was additionally expressed in immature odontogenic epithelium and cells of endodermal origin. Sox2 was observed in mature satellite glial cells and mucous glands.
65
Conclusions: This case represents a unique teratoma localized to the coccygeal region of a cat. Sox2 was found in immature SCs and in immature odontogenic and endodermally-derived epithelium. However, Sox2 alone is not a specific marker of immaturity, as it was detected in mature non-myelinating SCs, mucous glands and satellite glial cells. Thus, colocalization of Sox2 with other cell markers is necessary for accurate identification. THE VALUE OF CYTOLOGICAL EXAMINATION OF CANINE MAMMARY TUMOURS I. Dolka *, A. Gruk-Jurka y, R. Sapierzyn0 ski *, P. Jurka y and D. qukasz* *Department of Pathology and Veterinary Diagnostics and yDepartment of Small Animal Diseases with Clinics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, Poland Introduction: Canine mammary tumours (CMTs) include a variety of histopathological forms and therefore their cytological diagnosis can be challenging. The aim of this study was to determine the accuracy of diagnostic cytology by comparison with histopathology of CMTs and to examine the correlation between cytology and clinical findings and postoperative outcome. Materials and Methods: Twenty-seven samples were obtained by fine needle aspiration (FNA) or tissue imprints for cytopathological examination (CP). These samples were stained by Giemsa. Histopathological examination (HP) was performed by evaluating HEstained sections. Histological and cytological grading was evaluated. Results: CP-HP accuracy for malignant and benign CMTs was obtained in 23/27 cases (85.2%). The sensitivity and specificity of CP was 83.3% and 100%, respectively. A p CP-HP correlation for tumour types occurred in 19/27 (70.4%) samples. The cytological grading and typing correlated with histological assessment. Diagnosis on cytological examination was not associated with clinical findings, overall survival (OS), but with a cause of death due to CMTs. Additionally, malignant, simple types of carcinomas (in cytology) tended to be associated with decreased OS. Shorter OS was significantly associated with tumour metastases and cause of death due to CMT. Conclusions: CP is a valuable diagnostic tool in differentiating between benign and malignant mammary lesions and in obtaining a pre-operative diagnosis. Cytological features of CMTs may predict histological grade. However, CP may not provide valuable prognostic information concerning overall survival in CMT patients. THE PRESENCE OF SHORT FORM OF RON/STK TRANSCRIPT COULD BE A PREDICTOR OF POOR OUTCOME IN FELINE MAMMARY CARCINOMAS L. Maniscalco *, S. Guil-Luna y, S. Iussich *, F. Gattino *, Y. Millan y, J. Martın de Las Mulas y and R. De Maria* *Department of Veterinary Sciences, University of Turin, Italy and y Department of Anatomy and Comparative Anatomical Pathology, University of Cordoba, Spain Introduction: RON/stk tyrosine kinase receptor, identified in the cat as feline-stk, is activated by MSP and overexpressed in human breast cancer. The human RON gene is able to generate respectively the full length (fl) and the short forms (sf) of the transcripts. sf-RON is generated from an alternative transcriptional start from a second promoter within intron 10, which preserves the kinase activity of the receptor. The aim of this research was to investigate the expression of both RON and MST and to identify the presence of the sf-RON transcript in feline mammary carcinomas (FMCs) in relation to clinicopathological findings. Materials and Methods: Immunohistochemical expression of RON and MSP was evaluated on 50 FMCs. To detect sf-RON, RNA was extracted from 47 FMCs and RT-PCR, with primers annealing on exons 10 and 11, was performed on cDNA. Results: Immunohistochemical expression of RON and MSP was observed in 68% and 58% of FMCs, respectively, while 52% of the cases co-expressed both proteins. Expression of RON, MSP or both in FMCs was not correlated with clinical outcome. Feline sf-RON was detected in 27/47 FMCs and was significantly associated with poorly differentiated histological grade. Queens with FMC showing