Bilateral Testicular Leydig Cells Tumour in a Donkey

A rare case of a bilateral Leydig cells tumour located in the testis of a 15-year-old donkey slaughtered normally is presented. Histologically, the testicular tumour showed neoplastic Leydig cells arranged in solid growth as a pseudoadenomatous packet type. To our knowledge, this is the first bilateral Leydig cells tumour, a neoplasm never reported in the donkey.     

Penile and preputial squamous cell carcinoma in the horse and proposal of a classification system

Squamous cell carcinoma (SCC) is the most common tumour of the penis and prepuce of the horse and is found mainly in older animals. Reports on breed predilection for penile tumour formation are equivocal but castration, coat colour, poor genital hygiene and various infectious agents have been suggested to predispose to the development of SCC. Careful assessment of the primary tumour is an important first step in the design of an optimal treatment protocol. Tumour size, invasiveness, differentiation grade and presence of metastases are relevant to the decision to pursue additional diagnostic procedures or specific treatment options. Complete elimination of the neoplasm and, therefore, risk of recurrence is highly dependent on the type of therapy chosen. However, the size and histopathological features of the primary tumour are also important factors with respect to prognosis. This review describes the clinical and pathological features of penile and preputial SCC in the horse and proposes a standard staging system.     

Immunohistochemical expression of HER - 2 and Ki - 67 in granulosa cell tumor in bitches

Granulosa cell tumour, an ovarian neoplasm of stromal origin, is an important tumour related to oestrogenic dominance syndrome and cystic endometrial hyperplasia–pyometra complex. In order to analyse ovarian tumour´s malignant potential, immunohistochemical markers can be used, such as anti-HER2 and anti-Ki-67. The aim of this study was to evaluate the expression of immunohistochemical markers HER-2 and Ki-67 in granulosa cell tumour from bitches´ ovaries. In HER-2 immunomarker analysis using the HercepTest^® method, most tumours were classified as 2+ (moderate labelling). Concerning Ki-67 immunomarker, only one case was described as having a high proliferative index. An association was found between immunostained cell percentage by anti-HER-2 antibodies and high pleomorphism, represented by the pattern of follicular/trabecular tumour arrangement. There was no correlation between anti-Ki-67 and anti-HER-2 antibody immunostaining intensities, probably due to only one case with a high Ki-67 index. With an effective protocol for HER-2 and Ki-67 immunohistochemical identification in granulosa cell tumours in bitches, it was possible to characterize this neoplasm proliferation profile.     

Casual discovery of a thoracic tumour showing histological features of undifferentiated pleomorphic sarcoma in a male Wistar laboratory rat

Sarcomas are neoplasms of mesenchymal origin, with a predominant cell population mimicking the organization of various soft tissues and/or bones. Previous categorizations also included the possibility of the presence of tissue macrophage-like (histiocytes) neoplasm cells, in a tumour described as malignant fibrous histiocytoma, but this group has been considered as a variety of undifferentiated pleomorphic sarcomas. Although this kind of malignancy is not rare in humans, only few cases have been reported in laboratory animals. We report an unusual single case of spontaneous tumour growth, detected by casual observation, in the left thoracic area of an 18-month-old male laboratory Wistar rat. Both this individual and his ancestors were not exposed to any known carcinogenic substance or radiation, thus suggesting the development of the neoplasm as a spontaneous event. The mass was extracted surgically under general anaesthesia, and slices were examined histologically and immunohistochemically, using photon microscopy. The pathologist reported the presence of a combination of fibroblasts and undifferentiated mesenchymal cells arranged in a storiform pattern. Immunohistochemistry was performed on the tissue using specific antibodies for several proliferation (Ki-67) and differentiation (S-100, CD-34, CD-68, pan-keratin, desmin and smooth muscle actin-SMA) markers. Positive reaction was observed for S-100, Ki-67, CD-68, desmin and SMA (limited) but not for CD-34 or cytokeratin.     

Penile and preputial tumours in the horse: literature review and proposal of a standardised approach

Penile and preputial tumours are not uncommon in the horse, but can cause discomfort and lead to serious complications. Several types of tumour of the male external genitalia have been described. The most common type is the squamous cell carcinoma (SCC), which is found mainly in older horses. Reports of a breed predilection for penile tumour formation are equivocal, but castration, coat colour, poor hygiene and various infectious agents have all been suggested to predispose to the development of some types of tumour (e.g. SCC, papilloma and melanoma). Careful assessment of the primary tumour is an important first step in the design of an optimal treatment protocol. Invasiveness, differentiation grade, tumour size and presence of metastases are all relevant to the decision to pursue additional diagnostic procedures or specific treatment options. To date, no standard protocol has been reported for the approach to penile tumours in the horse and treatments range from minimally invasive therapies (e.g. topical use of 5-fluorouracil) to radical surgical interventions (e.g. en bloc penile and preputial resection with penile retroversion). Completeness of removal of the neoplasm and therefore risk of recurrence is highly dependent on the type of therapy chosen. However, the size and histopathological features of the primary tumour are also important factors with respect to the likelihood of recurrence. This review describes the most common penile and preputial neoplasms in the horse, and outlines a standard protocol aimed at arriving at a specific diagnosis and tailoring the therapeutic approach accordingly.     

Giant cell tumour of bone in a cat

A domestic shorthaired cat had a firm, non-painful swelling of the left antebrachium. Radiographs showed an expansile, multiloculated lesion in the radius. The mass gradually enlarged over the following four and a half months and the animal became completely lame. The histological diagnosis was giant cell tumour of bone; this is a rare neoplasm of bone in veterinary patients. Giant cell tumour of bone should be considered in the differential diagnosis of bone lesions having an expansile, multiloculated radiographic appearance.     

Tumour angiogenesis,anti‐angiogenic therapy and chemotherapeutic resistance

In order for a tumour to continue to grow and disseminate, it must acquire a new blood supply. Neovascularisation can be enacted by a number of different mechanisms. This dependence of tumour progression on an augmented vascular supply has been exploited by the development of anti‐angiogenic drugs, which are designed to inhibit new blood vessel formation or disrupt existing tumour‐associated vasculature, both leading to ischaemic–hypoxic tumour cell death. However, the clinical benefits of these therapeutic approaches are frequently variable and often transient, the neoplasm sometimes being able to use other neovascularisation mechanisms to maintain its blood supply and thus evade the current anti‐angiogenic therapy. Tumours may also develop a more malignant phenotype following this treatment. Clinical outcomes may be improved by simultaneously inhibiting different angiogenic pathways, abetted by more effective drug delivery regimens such as metronomic chemotherapy and the concurrent use of other antitumour modalities.     

Multilobular tumour of bone at an unusual location in the axilla of a dog

Multilobular tumour of bone is a rare neoplasm of cartilage, bone and connective tissue that is seen almost exclusively in association with the skull of veterinary patients. A four-year-old, spayed Jack Russell terrier was presented to the University of Georgia Veterinary Teaching Hospital because of a progressive swelling in the right axilla. Radiographs of the region showed the mass to be caudal to the scapula, unattached to bone and to have numerous punctate calcific opacities throughout its substance. Excisional biopsy of the mass was carried out under general anaesthesia and histopathological examination showed it to be multilobular tumour of bone. This case report documents the occurrence of multilobular tumour of bone at a site other than the head. This tumour should be considered in the differential diagnosis of soft tissue masses with calcific opacities.     

Malignant peripheral nerve sheath tumour of the urinary bladder in a cat

A 14-year-old domestic shorthair cat presented with a 5-month history of urinary incontinence and inappro-priate elimination. Ultrasonography revealed a well-marginated, vascular mass of mixed echogenicity ex-tending from the dorsal wall of the urinary bladder into the lumen. Partial cystectomy was performed for re-moval of the urinary bladder mass; histopathological evaluation revealed a spindle cell neoplasm with a prominent palisading pattern. Histomorphologic features and immunohistochemical demonstration of vimentin, glial fibrillary acidic protein and S-100 protein, combined with negativity for smooth muscle actin and desmin were consistent with malignant peripheral nerve sheath tumour. This case report describes a novel location of malignant peripheral nerve sheath tumour; to the authors' knowledge, the bladder has not been described as a site of origin in the cat or any other domestic species.     

Testicular Neoplasms (Interstitial and Sertoli Cell Tumours) in a Domestic Ferret (Mustela putorius furo)

Unilateral testicular enlargement was detected in a 5‐years‐old domestic ferret during a routine sterilization. The right testicle showed two different types of proliferative lesions: (i) round nodules, well demarcated, showing a soft yellow tissue; (ii) white nodules, firm, with irregular‐shaped invaginations. Microscopically, the neoplastic proliferations were identified as an interstitial neoplasm and Sertoli cell tumour, respectively. The left testicle was small and showed intense testicular atrophy. Clinical evaluation of the ferret did not show any other apparent pathological processes. This study is the first case reporting the concomitant occurrence of a Sertoli cells tumour and an interstitial cell tumour in a domestic ferret.     

Histopathological and immunohistochemical characteristics of two canine lipid-rich mammary carcinomas

Clinicopathological and immunohistochemical findings of two uncommon canine lipid-rich mammary carcinomas are described. The predominant histological feature in both tumours was the presence of at least 80% of cells with intracytoplasmic vacuoles which stained positively with Sudan IV but not with alcian-blue periodic acid-schiff method. In both tumours, small groups of non-vacuolated cells were identified among the vacuolated cells. However, histological and immunohistochemical differences were also found between these tumours. Thus, one of them was composed of tumour cells with a large and single vacuole, which were arranged in lobular pattern, while the other neoplasm showed an intraductal growth of tumour cells with a fine vacuolated cytoplasm. Immunohistochemically, in the first tumour most vacuolated cells were positive for CK (cytokeratin)8-7, indicating a secretory epithelial immunophenotype while CK5 and CK8-7-expressing non-vacuolated cells were associated with luminal duct immunophenotype. However, in the second tumour the expression of CK14 in most of vacuolated cells and alpha-smooth muscle actin (alpha-SMA) in non-vacuolated cells, alone or in combination with CK5 suggested a myoepithelial immunophenotype for both cell types. These results suggest heterogeneity of the cell type and growth pattern for this type of canine tumour as has been described in women but not in dogs.     

Identification of novel tumour‐associated antigens in canine mammary gland tumour

Canine mammary gland tumour (MGT) is the most common neoplasm in female dogs and has similar biological characteristics to human MGT. Spontaneous canine MGT is a more attractive clinical model in oncological research than that of the murine experimental model. Tumour‐associated antigens (TAAs), which are produced in tumour cells, are applied as tumour markers, tumour vaccine antigens and molecular targets of therapeutic drugs. In this study, we have primarily identified 13 different TAAs of canine MGT by serological immunoscreening of cDNA expression library. The results of serological mini‐arrays of identified antigens showed that CCDC41 antigen specially reacted with 35% of sera from MGT‐dogs and did not react with control sera. We also found that HSPH1 mRNA expression levels increased significantly in MGT tissues. These findings will contribute to the development of diagnostic technologies and translational target therapies for dogs. Clinical relevance : HSPH1, which is strongly expressed in the tumour tissue, will be a possible vaccine antigen of canine MGT.     

Biology, diagnosis and treatment of canine appendicular osteosarcoma: similarities and differences with human osteosarcoma

Osteosarcoma (OSA) is the most common primary bone tumour in dogs. The appendicular locations are most frequently involved and large to giant breed dogs are commonly affected, with a median age of 7–8 years. OSA is a locally invasive neoplasm with a high rate of metastasis, mostly to the lungs. Due to similarities in biology and treatment of OSA in dogs and humans, canine OSA represents a valid and important tumour model. Differences between canine and human OSAs include the age of occurrence (OSA is most commonly an adolescent disease in humans), localisation (the stifle is the most common site of localisation in humans) and limited use of neoadjuvant chemotherapy in canine OSA.     

Surgical treatment of intramedullary spinal cord neoplasia in two dogs

An area of intramedullary spinal cord enlargement at the thoracolumbar junction was identified by myelography in each of two dogs, Exploratory laminectomy followed by durotomy and myelotomy permitted removal of an intramedullary neoplasm in each dog. In one animal the tumour was diagnosed to be an ependymoma, in the other the tumour had the characteristics of a nephroblastoma. Following surgery each dog recovered quickly to pre-operative status or better. In one dog there was long term resolution of neurological deficits, while the other was euthanased because of persistent faecal incontinence.     

Glomangioma in the Prepuce of a Dog

A case of preputial glomangioma in an 8-year-old Springer Spaniel dog is reported. The dog presented a solitary nodular mass, approximately 3.5 x 5.2 cm in diameter, located on the lateral wall of the prepuce at the base of the penis. Histologically, the excised tumour mass consisted of proliferating round epithelioid cells arranged in a cordon-like structure around small blood vessels. The neoplastic cells were positive for alpha smooth muscle actin and negative for cytokeratin, desmin, S-100 protein and neurone-specific enolase. Based on these pathologic features, the tumour was diagnosed as glomangioma, a neoplasm extremely rare in dogs. To our knowledge, this is the first report of preputial glomangioma in the dog.     

Granular cell myoblastoma in the tongue of a dog: A case report

A granular cell myoblastoma was found in the dorsal side of the tongue of a 9‐year‐old female mongrel Pinscher. Macroscopically the tumour was white, well circumscribed, and 1½> cm in diameter. Microscopically the tumour cells were arranged in small compact nests or cords with delicate, poorly vascularized collagen bundles in between. A cinar structures were found, also a few mitotic figures were present. Cytoplasmic granules showed a positive periodic acid Schiff reaction. Ultrastructural features included indented nuclei and small‐sized vesicular cytoplasmic granules.

The histogenesis of the neoplasm remains uncertain.     

Outcome following treatment of soft tissue and visceral extraskeletal osteosarcoma in 33 dogs: 2008–2013

Extraskeletal osteosarcoma (EOS) is a rare, highly malignant mesenchymal neoplasm arising from viscera or soft tissues characterised by the formation of osteoid in the absence of bone involvement. Owing to the rarity of these neoplasms very little information exists on treatment outcomes. The purpose of this study was to describe the outcome following surgical treatment of non‐mammary and non‐thyroidal soft tissue and visceral EOS in dogs. Thirty‐three dogs were identified; the most common primary tumour site was the spleen. Dogs that had wide or radical tumour excision had longer survival times compared with dogs that had only marginal tumour excision performed [median survival time of 90 days (range: 0–458 days) versus median survival time of 13 days (range: 0–20 days)]. The use of surgery should be considered in the management of dogs with non‐mammary and non‐thyroidal soft tissue and visceral EOS.     

A Clinico-pathological study on the effect of vincristine on transmissible venereal tumour in dogs

Transmissible venereal tumour (TVT) is a coitally transmitted neoplasm of dogs and is common among sexually active dogs, where sexual behaviour is not under control. Several treatment options are available for the treatment of the tumour, with chemotherapy being the most commonly employed. In this study, we investigated the clinical and cytological changes after weekly vincristine sulphate administration in 38 cases of naturally occurring TVT. Tumours totally regressed in 31 dogs after two to seven doses (mean 3.54 +/- 1.01) of vincristine. One dog died after the fifth dose of vincristine, and in six dogs, an additional treatment with doxorubicin was needed. Masses were still present in four dogs and the histopathological examination revealed small nodules of granulation tissue in two dogs, while viable tumour cells were identified in the remaining two cases. No recurrences were observed in a follow-up period of 7-49 months (mean 13.64 +/- 9.66); in one dog, granulation tissue was detected in the surgery site after 2 months. Treatment success could easily be followed by the cytological changes. In conclusion, vincristine was found to be effective chemotherapeutic agent.     

Feline non-ocular melanoma: a retrospective study of 23 cases (1991-1999).

Non-ocular melanoma is considered to be a rare neoplasm in cats; however, more than 150 cases have been reported in the literature since 1961. The objective of this study was to characterise this tumour better by evaluating case outcome and survival data for cats with melanoma and to compare clinical and histopathological findings with those of previous reports. Twenty-three feline non-ocular melanomas were identified, the most common locations being the nose, digit and pinna. Cats with digital melanomas had survival rates similar to their canine counterparts. Histological assignation of benignity, malignancy or junctional activity was not found to be an accurate predictor of clinical behaviour. Melanoma should be considered as a differential diagnosis for cats presenting with pigmented or non-pigmented masses and histopathology is essential for definitive diagnosis, as other tumours may clinically appear quite similar. Regular follow-up examinations are recommended indefinitely for benign or malignant feline melanomas.