Uterine extramedullary plasmacytoma in a dog

Parotid Salivary Gland Extramedullary Plasmacytoma with Local Lymph Node Metastasis in a Dog

A 12 yr old spayed female mixed-breed dog presented for evaluation of a recurrent soft-tissue sarcoma. On physical examination, a firm mass was palpated ventral to the left ramus of the mandible. A fine-needle aspirate of the mass was suggestive of a round-cell neoplasm. A complete blood count, serum biochemical profile, and an abdominal ultrasound with liver and splenic aspirates were performed, and no clinically relevant abnormalities were identified. Advanced imaging of the skull identified an enlarged parotid salivary gland and an enlarged ipsilateral medial retropharyngeal lymph node. The medial retropharyngeal lymph node was sampled via fine-needle aspiration, and a round-cell population similar to what was present in the mass was identified. An incisional biopsy was performed under general anesthesia, which yielded a diagnosis of salivary gland extramedullary plasmacytoma, confirmed with immunohistochemistry (MUM-1). The parotid salivary gland and medial retropharyngeal lymph node were then surgically excised, and metastasis to the lymph node was confirmed by histopathology. The dog remained alive for 685 days after surgery until she was euthanized for hindlimb paresis of undetermined cause.

Radiographic and ultrasonographic findings of uterine neoplasms in nine dogs

The records of nine female intact dogs with histologically confirmed uterine tumors were reviewed retrospectively, and the related radiographic and ultrasonographic signs of the lesions detected were recorded. Radiography revealed a soft-tissue opacity between the urinary bladder and colon in six of seven dogs with uterine body and/or cervical tumors, and a soft-tissue opacity in the midventral abdomen in two dogs with uterine horn tumors. Ultrasonography revealed masses in all dogs with uterine body/cervical tumors and could delineate the origin of the mass in one of two dogs with uterine horn tumors. The mass was characterized ultrasonographically as solid in three dogs (all leiomyomas), solid with cystic component in four dogs (two adenocarcinomas, one leiomyoma, and one fibroleiomyoma), and cystic in two (both leiomyomas). Hyperechoic foci in the mass were observed in three dogs. Ultrasonography was a useful method for demonstrating uterine body and/or cervical tumors. However, it was not possible to ascertain sonographically that a mass originated in a uterine horn unless there was associated evidence of uterine horn to which the mass could be traced. The ultrasonographic appearance of uterine tumors was variable, and the type of neoplasm could only be determined by taking biopsies of the mass.

First report of an endometrial adenoacanthoma in a dog

Uterine adenoacanthoma, a subtype of primary endometrial adenocarcinoma, was found in a tissue specimen removed during ovariohysterectomy from an 8-year-old German Shepherd dog. Multifocal, benign squamous metaplastic islands were identified in the parenchyma of the malignant endometrial tumour. The tumour was highly infiltrative but did not metastasise to other organs. Detailed immunohistochemical analyses were carried out in order to characterise the immunophenotype of the tumour.

Uterine leiomyosarcoma and pyometra in a dog

A seven-year-old entire female, mixed-breed dog, weighing 19 kg, was presented with a 2-day history of abdominal distension, reduced appetite and general dullness. Abdominal palpation revealed a large mass. Radiography showed a large mass occupying the left mid-abdominal area and convoluted loops of tubular fluid opacity occupying the right mid-abdominal area. Ultrasonography revealed a large heterogeneous mass with an anechoic area and some hyperechoic foci, indicative of calcification, in the mid-abdominal area. Furthermore, hypoechoic areas were found in the middle and caudal abdominal area and were presumed to be the fluid-filled uterine horns. At laparotomy, a 10·5×14·5-cm firm mass was found in the uterine body, while the uterine horns were filled with a thick red-brownish exudate; ovariohysterectomy was subsequently performed. A diagnosis of uterine leiomyosarcoma associated with pyometra was established by histopathology and immunohistochemistry.

Penile extramedullary plasmacytoma in a dog

Penile tumours are rare in dogs. Reported herein is a case of a penile extramedullary plasmacytoma (EMP) in a 5-year-old male cocker spaniel that was brought to a local hospital for an evaluation of a penile mass. The mass was approximately 1.3 cm in diameter at the time of presentation. In fine needle aspiration and histopathological examinations, the neoplastic cells showed eccentric round nuclei, a moderate amount of basophilic cytoplasm, and a peri-nuclear clear zone, consistent with plasma cell morphology. There was nuclear pleomorphism with mononuclear giant cells and occasional bi-nucleation. Round cells on the periphery of the mass demonstrated plasmacytic differentiation. Immunohistochemically, the neoplastic cells stained positive for MUM1 and light lambda chain. Based on the cytological and pathological observations, a diagnosis of penile EMP was established.

Solitary Intracerebral Plasmacytoma in a Dog: Microscopic, Immunohistochemical, and Molecular Features

A primary intracerebral plasmacytoma was identified in a 7-year-old spayed female Boston Terrier. Grossly, a well-demarcated, 2 cm in diameter, roughly spherical tumor was in the rostral aspect of the left cerebral hemisphere. Histologically, the neoplasm was composed of sheets of round cells with distinct plasmacytoid features and marked anisocytosis and anisokaryosis. Cells were positive for vimentin, CD18, CD79a, and lambda light-chain, and negative for kappa light chain, cytokeratin, lysozyme, glial fibrillary acidic protein, and S100 protein. Clonally rearranged B-cell antigen receptor genes were detected by PARR (polymerase chain reaction for antigen receptor rearrangements), confirming clonal proliferation of B lymphocytes. Although primary solitary intracerebral plasmacytoma is rare in dogs and other species, it should be included in the differential diagnosis for central nervous system round-cell neoplasms. Clonality testing can be utilized to support the histological diagnosis of this neoplasm type.

Endometrial adenocarcinoma and mucometra in a 6-year-old Alaska Malamute dog

A 6-year-old female Alaska Malamute dog was presented for evaluation of abdominal enlargement referred by a local veterinarian. On the history, the owner complained of chronic abdominal enlargement initiated more than 4 months ago, reduced appetite, occasional vomiting and general dullness. He also complained of greenish mucous intermittent vaginal discharge starting 10 days ago. The bitch was chronically treated with medroxiprogesterone acetate. A laparatomy was performed and fluid in the abdomen was found and aspirated during the surgery. Also a very fluid-filled distended uterus and a mass in the distal part of the left uterine horn were found. The mass was encapsulated by the omentum, but areas of necrosis and calcification were identified. Histopathological diagnosis was endometrial adenocarcinoma.