Primary renal mixed tumor characterized by marked proliferation of osteoblast-like cells with osteoid formation in a swine.

Renal mixed tumor characterized by the absence of nephrogenic blastema and the presence of predominant osteoid-producing osteoblast-like cells occurred in the kidney of a 6-month-old, hybrid, female pig. At the post-mortem examination, the tumor was found as a calcified grayish-white mass at the cranial end of the left kidney. Histologically the tumor consisted of 3 growth areas of poorly differentiated spindle cells, osteoid-producing osteoblast-like cells, and luminal epithelial cells. Transition from the spindle cells to the osteoblast-like cells or the luminal epithelial cells was observed. Immunohistochemically, the spindle cells and the osteoblast-like cells were consistently positive for ß-catenin. Although the luminal epithelial cells and adjacent spindle cells were positive for cytokeratin, these 3 types of tumor cells were consistently negative for WT1. The tumor was diagnosed as primary renal mixed tumor characterized by marked proliferation of osteoblast-like cells with osteoid formation.

A cutaneous mixed tumor in a dog.

The atypical cutaneous tumor of a 9-year-old mixed breed female dog was examined. The tumor was well-demarcated and histologically composed of a trichoblastic area, tricholemmal area and apocrine glandular area. Neoplastic cells in trichoblastic area and tricholemmal area had PAS-positive granules in the cytoplasm and were positive for pan-cytokeratin, cytokeratin 5/6, 14 and 19 and p63. Neoplastic cells in trichoblastic area were also positive for cytokeratin 15 and CD34. Neoplastic cells in apocrine glandular area were positive for pan-cytokeratin and cytokeratin 7, 18 and 19. Myoepithelial cell proliferation with osteocartilaginous metaplasia was observed in this area. Since neoplastic cells showed multiphenotypic differentiation for hair follicles and apocrine glands, the present case was diagnosed as a cutaneous mixed tumor.

Canine mammary mixed tumours: immunohistochemical expressions of EGFR and HER-2.

BACKGROUND: Benign mixed tumours (BMTs) are frequently found in the mammary glands of female dogs, but the factors determining malignant transformation in these tumours are unknown. OBJECTIVE: To evaluate the expression of the oncoproteins, human epidermal growth factor receptor 2 (HER-2) and epidermal growth factor receptor (EGFR), in 46 carcinomas in BMTs (CBMTs) and to verify their possible association with the malignancy of the tumours. METHODS: Immunohistochemical expression was analysed in benign and malignant components separately, and then compared with 74 cases of BMTs. RESULTS: Among the CBMTs, positivity for HER-2 was found in the benign histological component of 4.3% (2/46), in the malignant epithelial non-invasive component of 14.8% (4/27) and in the malignant invasive epithelial component of 13.6% (6/44) of cases. Two of the 24 (8.3%) BMTs were positive for HER-2. There was no relationship between HER-2 and the tumour components. There was no significant difference between BMTs and CBMTs. Positivity for EGFR was found in the benign component of 17.4% (8/46) of the CBMTs, in the malignant epithelial non-invasive component of 40.7% (11/27%) and in the invasive epithelial malignant component of 45.4% (20/44). EGFR positivity was significantly associated with the invasive component of CBMTs. CONCLUSION: EGFR may contribute to malignant epithelial transformation of BMTs. In contrast, HER-2 overexpression may not be associated with the acquisition of a malignant epithelial phenotype.

Canine mammary gland tumours; a histological continuum from benign to malignant; clinical and histopathological evidence.

This study describes the clinical and histopathological findings in dogs with mammary gland tumours, and compares the histopathological and clinical evidence consistent with progression from benign to malignant to human breast cancer epidemiology. Clinical and histopathological data on 90 female dogs with 236 tumours was included. Dogs with malignant tumours were significantly older than dogs with benign tumours (9.5 versus 8.5 years), P = 0.009. Malignant tumours were significantly larger than benign tumours (4.7 versus 2.1 cm), P = 0.0002. Sixty-six percent had more than one tumour, and evidence of histological progression was noted with increasing tumour size. Dogs with malignant tumours were significantly more likely to develop new primary tumours than dogs with benign tumours, P = 0.015. These findings suggest that canine mammary tumours progress from benign to malignant; malignant tumours may be the end stage of a histological continuum with clinical and histopathological similarities to human breast carcinogenesis.

Evaluation of serum haptoglobin and C-reactive protein in dogs with mammary tumors.

BACKGROUND: In veterinary medicine, there is increasing interest in measuring acute phase proteins as a tool in the diagnosis and monitoring of neoplastic diseases. Although mammary neoplasms are the most common type of cancer in dogs, acute phase proteins have not been extensively evaluated in dogs with mammary tumors. OBJECTIVES: The aim of this study was to evaluate serum haptoglobin (Hp) and C-reactive protein (CRP) concentrations in the dogs with mammary tumors and assess their potential association with malignancy. METHODS: A retrospective study of dogs with mammary tumors was performed. Serum concentrations of CRP and Hp were determined in healthy control dogs (n=20) and dogs with mammary tumors before surgery (n=41). Mammary tumors were grouped as carcinomas (n=24), fibrosarcoma (n=1), malignant mixed tumors (n=7), benign mixed tumors (n=6), and adenomas (n=3). CRP and Hp concentrations were compared in dogs with different tumor types and were also compared based on tumor size, lymph node infiltration, skin ulceration, fixation to underlying tissue, and time between tumor identification and removal. RESULTS: Hp concentration was significantly (P<.043) higher in dogs with mammary tumors (median 2.03 g/L, range 0.09-2.94 g/L) compared with controls (1.38 g/L, range 0.08-3.00 g/L), but the range of values overlapped considerably. CRP concentration was higher in dogs with carcinomas (4.70 mg/L, range 0.63-128.96 mg/L) vs controls (2.11 mg/L, range 0.25-6.57 mg/L) (P=.0008) and in dogs with ulcerated skin (14.8 mg/L, range 5.7-128.9 mg/L, n=3) compared with those without ulceration (2.4 mg/L, range 0.11-30.3 mg/L, n=38) (P=.048). CONCLUSIONS: Serum Hp and CRP do not appear to have value in diagnosing or predicting malignancy of mammary tumors in dogs. Higher CRP concentrations in dogs with mammary carcinoma suggest a role for inflammation in this tumor type.

Immunohistochemical expression of p63 and deltaNp63 in mixed tumors of canine mammary glands and its relation with p53 expression.

The immunohistochemical expression of p63, DeltaNp63, and p53 was studied in mixed tumors of canine mammary glands (13 benign mixed tumors and 19 carcinomas arising from benign mixed tumors) to determine the role of p63 and its isoform DeltaNp63 in the development of mixed tumors, as well as to assess its relation with p53. P63 was expressed in myoepithelial cells of all benign mixed tumors and in 18 of 19 carcinomas in mixed tumors. The p63-negative carcinoma in mixed tumors was invasive, and a loss of p63 was detected in the other malignant tumors showing a discontinuous p63-stained myoepithelial layer. DeltaNp63 was expressed in all benign mixed tumors but only in p63-positive carcinomas in mixed tumors. Despite its positive correlation with p63 expression in carcinomas in mixed tumors (r = 0.8323, P < .00001), DeltaNp63 expression showed a decrease in benign tumors. Positivity for p53 was detected in 2 of 13 and 1 of 19 benign mixed tumors and carcinomas in mixed tumors, respectively. There was no correlation between p63 or DeltaNp63 and p53 expression. Our data support the notion that the decrease of p63 expression, in particular of its isoform DeltaNp63, seems to be an important factor in the development of carcinomas in mixed tumors.

Magnetic resonance imaging technique for the examination of canine mammary tumours.

The aim of this study was to adapt the human magnetic resonance imaging (MRI) sequences for use in the routine examination of canine mammary glands. MRI was performed on 10, middle- to old-aged dogs of different breeds. It was found that T1- and T2-weighted spin echo, short T1 inversion recovery sequences and a gradient echo (GE) dynamic T1-weighted measurement made in the coronal and transversal planes were the most informative MR diagnostic methods for imaging canine mammary tumours. The static MR technique is the most detailed imaging modality for differentiating the tissue types in the substance of the mammary gland. The MRI findings were in close relationship with the histological result (five malignant mixed tumours and five cases of invasive ductal carcinoma). Using the GE dynamic contrast-enhanced sequence the morphological patterns as well as the kinetic parameters proved to be malignant. By the dynamic measurement technique initial information was obtained on the contrast enhancing properties, which are valuable factors during in vivo staging and in the prognostic work.

Histochemical and immunohistochemical characterization of canine mammary mucinous carcinoma.

Mucinous carcinoma is a rare mammary tumour, characterized by intracellular and extracellular mucin. It is still uncertain whether the origin of the mucin is epithelial, myoepithelial or fibroblastic. Eleven canine cases originally classified as mucinous carcinomas were reassessed and compared with myoepithelial nests of mixed tumours. All samples were examined (1) histochemically by the periodic acid-Schiff (PAS) and PAS-diastase methods, and with alcian blue (pH 2.5 and pH 1.0), mucicarmine and Grimelius silver stain, and (2) immunohistochemically for cytokeratin 19, vimentin, alpha-actin and chromogranin A. This examination revealed that only five of the 11 tumours were genuine mucinous carcinomas. In these five tumours the mucus-secreting cells showed cytoplasmic cytokeratin 19 positivity; the mucus showed PAS-diastase and mucicarmine positivity, and alcianophilia which was stronger at pH 2.5 than at 1.0. The remaining six cases were re-classified as mixed tumours because both mucus and mucus-producing cells shared the following similarities with myoepithelial nests of mixed tumours: vimentin and alpha-actin cytoplasmic positivity, PAS negativity, alcianophilia both at pH 2.5 and 1.0, and mucicarmine positivity.

Primary malignant mixed mesenchymal tumour of the heart in a dog.

A case of primary malignant mixed mesenchymal tumour of the heart in an 8-year-old golden retriever is described. The cardiac tumour, measuring 2.5 x 3 x 5 cm, was located in the posterior part of the atrial septum, extending into the surrounding region. Histologically, the tumour was composed of multiple mesenchymal elements of fibrosarcoma, rhabdomyosarcoma, liposarcoma and chondrosarcoma. No previous reports of such a tumour occurring in the heart of the dog were found in the literature.

Concentraciones séricas de hormona de crecimiento en perras con tumores mamarios espontáneos antes y después de la mastectomía / Growth hormone serum concentrations in bitches with spontaneous mammary tumors before and after mastectomy

La producción no pituitaria y autónoma de hormona del crecimiento (GH) en la grándula mamaria ha sido reportada en perros. Se determinó el impacto de la mastectomía de glándulas mamarias tumorales sobre las concentraciones séricas de GH, en casos clínicos de tumores mamarios espontáneos de dieciocho perras enteras, a las que se les realizó mastectomía de todas las glándulas tumorales. Tres perras sanas fueron mantenidas solo bajo protocolo anestésico por un período similar al del procedimiento quirúrgico. Se tomaron muestras sanguíneas por venopunción periférica para determinar GH sérica, antes (día -1), 2 y 11 horas y 7 y 14 días después de la mastectomía o de la anestesia. Se realizó el estudio histopatológico de las glándulas mamarias tumorales extirpadas en la cirugía. . La GH sérica fue determinada por un radioinmunoensayo homólogo de fase líquida. La media ñ SEM (ng/ml) del grupo tratado antes y después de la cirugía fue de 17.3ñ 2.8; 8.5ñ1.5; 6.3ñ1.1 y 6.1ñ1.5 para el día -1, 2 horas, 7 y 14 días respectivamente. Los mismos valores para el grupo control fueron de 4.2 ñ1.0; 5.5 ñ 1.3 y 5.2 ñ 1.5 para el día -1, 2 y 11 horas luego de la anestesia. Después de la cirugía, la GH sérica descendió (media ñ SEM) -22.6 por ciento ñ 4.9 a las 2, -31,8 por ciento ñ 5,1 al día 7, y -29,7 por ciento ñ 9 al día 15, mientras que en el grupo control se incrementó en un 31.1 por ciento ñ 08 y 26.3 por ciento ñ 9 a las 2 y 11 horas, respectivamente luego de la anestesia. La histopatología de las mamas tumorales analizadas reveló carcinoma tubular y papilar, adenocarcinoma, carcinosarcoma y carcinoma complejo. Se concluyó que en perras la GH ectópica es también producida por la glándula mamaria con tumores espontáneos malignos (AU)

In vitro efficacy of chemotherapeutics as determined by 50% inhibitory concentrations in cell cultures of mammary gland tumors obtained from dogs.

OBJECTIVE: To determine the 50% inhibitory concentration (IC-50) of carboplatin, cisplatin, and doxorubicin in cell cultures of mammary gland tumors obtained from dogs and to assess whether in vitro efficacy was within the range of clinically relevant concentrations, SAMPLE POPULATION: 30 mammary gland tumors excised from dogs. PROCEDURE: Cell cultures were established from the 30 tumors. Cultures then were treated with carboplatin, cisplatin, or doxorubicin. Growth inhibition of cultures was assessed via DNA measurement 24, 48, and 72 hours after treatment. The IC-50 values were calculated by use of linear interpolation. RESULTS: Cultures varied in their pattern of susceptibility. Doxorubicin induced significantly lower IC-50 values than the platinum derivatives. Cisplatin and carboplatin had comparable effects. The IC-50 values for carboplatin and doxorubicin were in the range of clinically relevant concentrations, but only part of the cisplatin cultures had IC-50 values within clinically relevant concentrations. We did not detect differences in the in vitro susceptibility among subtypes of tumors (ie, adenocarcinoma, solid carcinoma, malignant mixed tumor). CONCLUSION AND CLINICAL RELEVANCE: The IC-50 values determined in this study allowed assessment of in vitro drug efficacy of chemotherapeutics in cultures of mammary gland tumors obtained from dogs. Variations in susceptibility were evident and emphasize the importance of assessing susceptibility and resistance patterns for each tumor. Prospective studies to assess direct correlations between in vitro and in vivo efficacy must be performed to determine the clinical predictive value of this in vitro chemosensitivity assay for treatment of dogs with mammary gland tumors.

Apocrine gland tumor of the eyelid in a dog.

A 13-year-old male Shetland Sheepdog with progressive exophthalmos had a neoplastic mass in the ocular adnexa. Histologically, this neoplasm was composed of duct-forming epithelial cells with decapitation secretion. Tumor cells invaded the globe through the tunica conjunctiva and replaced the vitreous body. The cornea, iris, ciliary body, and retina were extensively destroyed. Both the epithelial and spindle-shaped myoepithelial cells showed nuclear atypia and mitotic activity in the globe. The primary tumor was diagnosed as adenocarcinoma, probably originating from apocrine sweat glands of the eyelid, and the infiltrating intraocular neoplasm was diagnosed as a malignant mixed tumor.

Ceruminous gland tumors in dogs and cats: a review of 124 cases.

The histological features of 124 ceruminous gland tumors from canine and feline biopsy submissions were reviewed. The tissues, which represented submissions from private veterinary practices and a veterinary college, included ceruminous gland adenocarcinomas and adenomas as well as a single, mixed ceruminous gland adenocarcinoma. A majority of the masses from both dogs and cats were identified as malignant processes.