Hypoglobulinemia in a dog with disseminated plasma cell neoplasia: Case report and review of the diagnostic criteria.

This is the first reported case of hypoglobulinemia in a dog with disseminated plasma cell neoplasia. A 6-year-old male intact Rottweiler was referred to the U-Vet Animal Hospital (Werribee, Vic, Australia) for weight loss, hyporexia, lethargy, vomiting, and soft stools. Examination of a buffy coat preparation and splenic and liver aspirates revealed a monomorphic population of plasmacytoid cells, and the same cells comprised approximately 90% of bone marrow samples submitted for cytologic and histologic evaluation. Biochemistry revealed a hypoglobulinemia, and the presence of an M-protein was not supported by serum and urine protein electrophoresis or serum immunofixation. Immunohistochemistry demonstrated strong nuclear labeling for MUM-1.

Mast cell and plasma cell collision tumor in the spleen of a dog.

A 9-year-old spayed female English Mastiff was referred for outpatient ultrasound due to a 3-week history of weight loss, vomiting, and decreased appetite. Abdominal ultrasound showed multiple splenic masses of varying sizes and serum chemistry panel showed hyperglobulinemia. Cytologic examination of fine-needle aspirates of the splenic masses indicated a mast cell and plasma cell collision tumor. Results of serum and urine protein electrophoresis and immunofixation indicated the plasma cell neoplasia was producing IgA immunoglobulins.

Two cases of feline paraneoplastic alopecia associated with a neuroendocrine pancreatic neoplasia and a hepatosplenic plasma cell tumour.

BACKGROUND: Feline paraneoplastic alopecia (FPA) is a rare condition listed among the cutaneous paraneoplastic syndromes, which occurs in association with pancreatic carcinoma, cholangiocarcinoma, hepatocellular carcinoma and metastatic intestinal carcinoma. OBJECTIVES: To describe the clinicopathological findings of paraneoplastic alopecia in two cats each with an uncommon tumour not previously reported in association with FPA. ANIMALS: Paraneoplastic alopecia was associated with neuroendocrine pancreatic neoplasia in a Persian cat and with a hepatosplenic plasma cell tumour in a domestic short hair cat. RESULTS: FPA was suspected based on age, rapid onset of clinical signs, ventral distribution of alopecia, shiny appearance of the skin and telogenization/miniaturization of the follicles on histopathology. The nature of the tumours was determined through cytology, postmortem, histopathological and immunohistochemical examination, and capillary immunoelectrophoresis. A causative association between the skin lesions and the tumour was suggested by clinical and histopathological features shared with previously published cases. CONCLUSIONS AND CLINICAL IMPORTANCE: Pancreatic neuroendocrine and plasma cell tumour should be considered as differential diagnoses when evaluating FPA.

Intraocular ALλ amyloidoma with plasma cell neoplasia in a cat.

An 11-year-old, neutered male domestic short-hair cat was presented with buphthalmos of the right eye and diagnosed with advanced glaucoma. Sonographic examination revealed an iridial thickening. Neoplasia was suspected and an enucleation was performed. Histopathology of the enucleated eye revealed abundant amyloid deposition predominantly in the anterior uveal tract accompanied by few to moderate numbers of well-differentiated plasma cells. The amyloid deposits were identified by staining with Congo red and showing green birefringence under polarized light. Immunohistochemically, amyloid and plasma cells stained intensely only with anti-ALλ antibody, supporting the amyloid tumor being an immunoglobulin-λ-light chain origin. Additional abnormalities included narrowing of the filtration angle and collapse of the ciliary cleft, and trabecular meshwork. One year post-enucleation, the cat was still healthy without signs of systemic amyloidosis or apparent metastatic disease. This is the first report of a cat with noncutaneous extramedullary plasmacytoma originating in the anterior uveal tract with resulting local amyloid.

Haemangiomas, leiomyosarcoma and myeloma caused by subgroup J avian leukosis virus in a commercial layer flock.

An outbreak of simultaneously occurring haemangiomas, leiomyosarcoma and myeloma was observed in a commercial layer flock in China. The sick chickens were extremely thin and dehydrated. Scattered haemangiomas were found on the claws, breast and wings. At necropsy, haemangiomas and some other nodular tumours were also found in the internal organs. In addition, diffuse enlargement of the liver and spleen appeared in some birds. Histopathologically, haemangiomas were typically cavernous haemangiomas and haemangioendothelioma. In the diffusely swollen liver and spleen, multifocal or widespread marrow tumour cells filled with ball-like acidophilic particles in cytosol were observed, which are the characteristic pathological changes of avian myelocytomatosis. The nodular tumour cells formed by muscle bundles were of variable size, irregular shape, poorly differentiated and malaligned. Immunohistochemistry for vimentin, cytokeratin, actin (smooth muscle) and actin (sarcomeric) and Masson's staining confirmed the different cell lineage of the nodular tumour, thus leading to the diagnosis of leiomyosarcoma. The seroprevalence of avian leukosis subgroup J (ALV-J) antibodies was 13.46% (7/52), while ALV-A/B and reticuloendotheliosis virus (REV) antibodies were not detectable. The DF-1 cells inoculated by virus extracted from liver samples from 24 infected chickens were cultured and the group-specific antigen (GSA) was identified by ELISA. All samples were positive for ALV, which was further identified as ALV-J by immunofluorescence assay (IFA). PCR analysis revealed that three isolates of ALV-J proviral sequence were close to the HPRS-103 prototype strain and other Chinese field strains isolated in recent years, while one isolate (DP01) had a lower homology with them. This is the first report that ALV-J infection caused the simultaneous occurrence of haemangiomas, leiomyosarcoma and myeloma in a commercial layer flock.

Detection of biclonal gammopathy by capillary zone electrophoresis in a cat and a dog with plasma cell neoplasia.

Gammopathies associated with plasma cell neoplasms in a 15-year-old female spayed domestic shorthaired cat and a 9-year-old female spayed Rottweiler dog were evaluated by serum protein electrophoresis. In the cat, the plasma cell neoplasm was found in the liver and spleen, and an evaluable sample of bone marrow was not obtained. Some of the plasma cells had the morphologic appearance of flame cells. The paraprotein was confirmed as IgG based on agar gel immunodiffusion precipitation and both immunocytochemical and immunohistochemical staining. The dog had multiple myeloma with production of IgG and IgA paraproteins. In both cases, serum proteins were evaluated by 2 methods of protein electrophoresis: cellulose acetate electrophoresis (CAE) and capillary zone electrophoresis (CZE). In the cat and the dog, CAE showed a single large oligoclonal-like peak, which occurred in the γ-region in the cat and the ß-γ-region in the dog, whereas CZE showed a biclonal gammopathy with 2 very close narrow spikes in the γ- and ß-γ-regions in the cat and dog, respectively. In selected cases, CZE may be more effective than routine CAE in distinguishing oligoclonal from monoclonal or biclonal paraproteinemia.