Mammary lipid-rich carcinoma with extensive amyloid deposition in a dog

A 6-year-old female Labrador retriever presented with a mass in the right mammary gland, and swollen right inguinal and axillary lymph nodes. Fine needle aspiration biopsy suggested a malignant lipid-producing tumor, such as liposarcoma. Histopathologically, the neoplasms were solid, lobulated nests of atypical epithelial cells with a large amount of extracellular deposits of amyloid in both mammary gland and lymph nodes. The proliferating cells contained large cytoplasmic vacuoles, positive for oil red-O. These cells were immunopositive for cytokeratin (AE1/AE3) and β-casein and negative for SMA. The amyloid deposits were immunopositive for β-casein. These findings suggested that the proliferating cells secreted β-casein forming amyloid deposits. This is the first report of mammary lipid-rich carcinoma with extensive amyloid deposition derived from β-casein.     

Carcinoma ex pleomorphic adenoma with sebaceous differentiation in the mandibular salivary gland of a dog

A carcinoma ex pleomorphic adenoma was diagnosed in the left mandibular salivary gland of an 8-year-old female spayed dog. The animal presented with a large nonpainful swelling in the left submandibular region. A computed tomography scan detected an irregularly enhancing soft tissue mass that was closely associated with the left external ear canal and extended to the left wing of the atlas. On surgical exploration, the mass was intimately associated with the left mandibular salivary gland. Both the mass and the adjacent gland were removed, and the diagnosis was determined by histopathology. The tumor was comprised of basaloid and low columnar epithelial cells, many glandular units formed by well-differentiated sebocytes, and multifocal regions of necrosis, mineralization, and hemorrhage. Salivary gland tumors with sebaceous differentiation are very rare in animals, with one previously reported case in a cat.     

Cyclosporine-responsive granulomatous sebaceous adenitis in a dog

Granulomatous sebaceous adenitis was diagnosed in a 2 year old spayed Miniature Pinscher. Initial treatment with isotretinoin for 3 weeks resulted in little response and decreased tear production. Immunosuppressive doses of prednisone for 3 weeks resulted in mild response of the dermatitis; however, the dog developed transient diabetes mellitus secondary to this treatment. Cyclosporine (5 mg/kg of body weight, po, q 12 h) resulted in good clinical response for 12 months, but histologically, the sebaceous glands remained absent. Although cyclosporine has immunosuppressive properties, this drug also has inhibitory effects of keratinocyte proliferation. These mechanisms may explain the beneficial response of cyclosporine in the treatment of granulomatous sebaceous adenitis in this dog.     

Mammary gland carcinoma in a dog with peripheral blood and bone marrow involvement associated with disseminated intravascular coagulation

A 7-year-old female Leonberger dog was referred to the National Veterinary School of Lyon Teaching Hospital with a 2-day history of anorexia and bleeding. A mammary mass had been removed 7 months earlier, but histologic examination was not performed. On physical examination, the dog was depressed and had pale mucous membranes and numerous petechiae and hematomas. Significant laboratory findings were moderate thrombocytopenia, prolonged prothrombin, activated partial thromboplastin, and thrombin times, hypofibrinogenemia, and increased concentration of fibrin(ogen) degradation products. A peripheral blood smear, buffy coat preparation, and bone marrow aspirate contained low numbers of large atypical cells that had moderate nuclear:cytoplasmic ratios, oval nuclei with multiple prominent nuclei, and basophilic cytoplasm with villous projections. A small nodule was found in the left inguinal mammary gland, and a fine-needle aspirate contained cells similar to those in blood and bone marrow. In samples of blood, bone marrow, and the mammary mass, the neoplastic cells were immunoreactive for cytokeratin. The diagnosis was mammary carcinoma with secondary disseminated intravascular coagulation (DIC) and disseminated tumor cells in bone marrow and circulating tumor cells in blood; this diagnosis was not confirmed by histopathologic examination. Owing to clinical deterioration and the poor prognosis, the dog was euthanized and a necropsy was not performed. This is the first report of a canine mammary carcinoma with circulating tumor cells and secondary DIC.     

CNS and lung metastasis of sebaceous epithelioma in a dog

Sebaceous epithelioma is a common canine cutaneous neoplasm characterized by a preponderance of basaloid cells with few well-differentiated sebocytes. It is considered a low-grade malignancy, as it may occasionally recur at the excision site; the possibility of lymph node metastasis is anecdotally reported, and distant metastases have never been observed. This case report presents the clinical and pathological features of a sebaceous epithelioma of the upper lip with a highly aggressive behaviour. The patient was a 9-year-old female dachshund that developed local recurrence 11 months after the excision of the primary sebaceous epithelioma and multiple lung and central nervous system metastases 5 months later. The designation epitheliomatous sebaceous carcinoma has been suggested for aggressive sebaceous epitheliomas, although differential criteria are still to be determined.     

Myelodysplastic syndrome with sideroblastic differentiation in a dog

A dog with myelodysplastic syndrome had microcytic hypochromic anemia, with siderocytes, poikilocytosis, hypersegmented neutrophils and giant platelets in peripheral blood. In bone marrow, the erythroid series showed immaturity, asynchronous maturation and sideroblasts. Dysgranulopoiesis and dysthrombopoiesis also were present, and hemosiderin was increased. Serum iron concentration was high, and both iron deficiency and lead toxicity were excluded as the cause of dyscrasia. This case represents a unique variant of myelodysplastic syndrome, best described as sideroblastic myelodysplasia. We propose the terms dyserythropoiesis, sideroblastic dyserythropoiesis, dyserythropoiesis with excess blasts, myelodysplasia and sideroblastic myelodysplasia to describe and categorize myelodysplastic syndromes in dogs.     

Paraneoplastic leukocytosis in a dog with a renal carcinoma

A 7-year-old male German Shepherd dog in poor body condition had a 3-month history of intermittent hematuria. Nonregenerative anemia, mild leukocytosis, marked hypoalbuminemia, and hematuria were observed. Subsequently, marked neutrophilia and moderate monocytosis were noted; anemia, hypoalbuminemia, and hematuria persisted; and the dog developed disseminated intravascular coagulation. Ultrasonographic examination of the abdomen revealed the presence of an enlarged and irregularly shaped right kidney with a large area of cavitation, and a nephrectomy was performed 30 days after initial examination. Cytologic examination of fine-needle aspirates and imprints of the right kidney revealed a neoplastic cell population suggestive of renal carcinoma. The histopathologic diagnosis was chromophobic cystic-papillary renal carcinoma. The tumor cells expressed granulocytic/macrophage-colony-stimulating factor (GM-CSF), detected by immunohistochemical staining, and elaboration of GM-CSF by the tumor may have mediated the leukocytosis in this dog. Following excision of the tumor, neutrophil and monocyte counts were only mildly increased. The dog died 135 days after initial presentation, and a necropsy was not permitted. Paraneoplastic neutrophilic leukocytosis is an uncommon finding and may be caused by elaboration of CSF by neoplastic cells.     

Multiple viral plaques with sebaceous differentiation associated with an unclassified papillomavirus type in a cat

Abstract

CASE HISTORY AND CLINICAL FINDINGS

A 15-year-old neutered male domestic short-haired cat was presented due to multiple 0.5–2?cm-diameter crusting plaques in the left preauricular region, over the bridge of nose, and in the right periocular region. The plaques did not appear to cause discomfort.     

Actinomyces infection in a dog with pulmonary carcinoma

Thoracic actinomycosis was diagnosed by bacterial isolation in a dog with a history of chronic productive cough, weight loss, pyrexia and a pulmonary mass lesion on radiography. Therapy with amoxycillin and clindamycin did not significantly improve the patient's condition and euthanasia was performed during exploratory thoracotomy. Histological examination of the affected lung lobes revealed the presence of peribronchiolar adenocarcinoma. Actinomycosis has been reported to co-exist with pulmonary neoplasia in humans and may mask the presence of malignancy.     

Paraneoplastic hypercalcemia in a dog with thyroid carcinoma

This case report describes a dog with thyroid carcinoma and paraneoplastic hypercalcemia. Following thyroidectomy the dog became hypocalcemic and required supplementation with calcitriol and calcium carbonate. During the following 2 years, attempts to reduce the supplementation resulted in hypocalcemia. The dog died from renal failure with no evidence of thyroid carcinoma.     

Hyperalbuminemia associated with hepatocellular carcinoma in a dog

Abstract: A 12‐year‐old, neutered male, mixed‐breed dog was presented to The Ohio State University Veterinary Teaching Hospital with a history of weight loss and weakness. Laboratory abnormalities reported by the referring veterinarian during the past year included increased alkaline phosphatase (ALP) activity, hyperalbuminemia, and nonregenerative anemia. On referral, the dog appeared hydrated and had moderate muscle wasting and hepatomegaly. A large lobular hepatic mass was observed ultrasonographically. Laboratory results included mild to moderate nonregenerative anemia, urine‐specific gravity of 1.035, 3+ proteinuria, increased serum activities of alanine aminotransferase (229 U/L, reference interval 10–55 U/L), ALP (813 U/L, reference interval 15–120 U/L), and the steroid‐induced isoform of ALP (676 U/L, reference interval 0–6 U/L), marked hyperalbuminemia (5.3 g/dL, reference interval 2.9–4.2 g/dL), and an increased A/G ratio (1.7). Hyperalbuminemia was confirmed by reanalysis on 2 different analyzers and by agarose gel electrophoresis, and colloid osmotic pressure (COP) was markedly increased (42.5 mmHg, reference interval 20–25 mmHg). Cytologic examination of a fine‐needle aspirate of the hepatic mass indicated hepatocellular proliferation; histologic examination of an excisional biopsy confirmed hepatocellular carcinoma. Three weeks after surgery, the albumin concentration, A/G ratio, COP, and ALT activity had normalized, but ALP activities remained high. We hypothesized that hyperalbuminemia developed secondary to hepatocellular carcinoma due to increased synthesis of albumin by malignant hepatocytes or due to decreased negative feedback from impaired hepatocellular osmoreceptivity. Hepatocellular carcinoma has been associated with paraneoplastic secretion of other proteins, but hyperalbuminemia has been reported only once in a human patient and has not previously in dogs.