Solitary extramedullary plasmacytoma of the canine larynx

A retrospective study of canine oral extramedullary plasmacytoma over a 15-year period (July 2004-July 2019): Treatment, histologic parameters and clinical outcomes

A total of 45 cases of canine oral extramedullary plasmacytomas (EMPs) presented to a tertiary referral institution over a 15-year period were examined. Histologic sections of 33 of these cases were examined for histopathologic prognostic indicators. Patients underwent variable treatment including surgical intervention, chemotherapy and/or radiation therapy. Long term survival was observed in the majority of dogs with a median survival time of 973 days (2-4315 days). However, almost 1/3 of dogs had progression of plasma cell disease, including two cases with myeloma-like progression. Histologic characterization of these tumours did not reveal criteria to predict tumour malignancy. However, cases without tumour progression did not exceed 28 mitotic figures in ten 400× fields (2.37 mm² ). All cases with tumour related death showed at least moderate nuclear atypia. Oral EMPs may represent a local manifestation of systemic plasma cell disease or singular focal neoplasia.

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.

Extramedullary Pulmonary Plasmacytoma in a Dog

In this case report we are presenting a rare case of primary pulmonary plasmacytoma in a dog in the context of clinical and pathological findings. A six-years-old, female Rottweiler was brought to the clinic with respiratory complaints. The patient was dyspneic and tachypneic, and there were friction sounds on auscultation of the lungs. Laryngeal and tracheal palpation induced severe cough. Lateral and ventrodorsal radiographs of the thorax showed increased opacity in the lungs and loss of cardiac silhouette. Based on clinical and radiological findings, diagnosis of a lung mass was made and surgery recommended. Under general anesthesia, bilobectomy of the right lung lobes by medial sternotomy was performed. Upon cytological and histopathological findings, plasmacytoma was diagnosed.

Feline Respiratory Extramedullary Plasmacytoma with Lymph Node Metastasis and Intrahistiocytic Amyloid

A 14-year-old domestic longhaired cat presented with a 2-year history of nasal discharge and a recent onset of inappetence and submandibular lymphadenopathy. The cat was humanely destroyed after developing severe respiratory distress. Necropsy examination revealed thickened nasal turbinates and soft palate, and friable red–tan material within the frontal sinus, nasal cavity and nasopharynx. The lungs contained multifocal irregular friable tan nodules. Multiple lymph nodes were enlarged, friable and red–tan in colour. Histopathology revealed a mature type extramedullary plasmacytoma (EMP) within the frontal sinus, nasal cavity, soft palate, larynx, trachea, lungs and multiple lymph nodes. The lymph nodes and larynx also contained marked granulomatous inflammation with extensive intrahistiocytic (and lesser amounts of extracellular) lambda light chain amyloid, confirmed by electron microscopy and immunohistochemistry. Neoplastic cells expressed CD79a and MUM1. This is the first report of an infiltrative EMP of the feline respiratory tract with lymph node metastasis and predominantly intrahistiocytic amyloid.

Plasmocitoma extramedular em bulbo peniano de cão: relato de caso

O objetivo deste relato de caso é descrever a ocorrência de plasmocitoma em bulbo peniano de um cão, classificado como uma doença extramedular não cutânea de localização rara e casuística inédita. Um cão, sem raça definida, com sete anos de idade e pesando 15kg, não castrado, apresentou histórico clínico de anorexia, vômitos, anúria e constipação. Ao exame específico da genitália externa, foi encontrada uma massa em bulbo peniano durante a inspeção do prepúcio, aderida à pele e encapsulada, extremamente firme e arredondada, medindo cerca de 6cm de diâmetro. Por meio da ultrassonografia dessa estrutura, foi observado aumento do volume regional com ecotextura heterogênea e ecogenicidade mista, além de neovascularização tecidual ao Doppler colorido. Foi realizada biópsia da massa, sendo verificada a presença de neoplasia de células redondas. A caracterização do tumor foi realizada pela imuno-histoquímica, e as células neoplásicas foram imunoexpressas para CD79a e MUM1, indicando o diagnóstico de plasmocitoma extramedular. Embora os tumores penianos em cães sejam os predominantemente venéreos transmissíveis (TVT), e os plasmocitomas sejam neoplasias raras nessa localização, este relato de caso fornece com ineditismo a ocorrência de plasmocitoma extramedular em bulbo peniano de cão, condição ainda não descrita em veterinária.

Cartilaginous Tumors of the Larynx and Trachea in the Dog

Cartilaginous tumors of the larynx and trachea are uncommon in the dog. The authors describe 10 cases diagnosed between 1995 and 2014 and review 16 cases in the literature. Seven of our cases were tracheal and 3 were laryngeal. Two of the laryngeal tumors were chondromas, which have not been previously reported in this site. The third laryngeal tumor was a myxochondroma. Of the 7 tracheal tumors, 6 arose from the ventral tracheal wall, including 2 that were extraluminal. Tracheal tumor types included chondrosarcoma ( n = 3), chondroma ( n = 2), and osteochondroma ( n = 2). All of the laryngeal tumors and 5 of 7 of the tracheal tumors occurred in adult dogs (aged 5–11 years). The 2 tracheal osteochondromas were in young dogs (3–4 months) and were intrathoracic, while the remaining tracheal tumors were cervical. Surgical excision had a good outcome in most cases. Combining our 10 cases with the 16 previously reported cases showed that 6 (27%) of the affected dogs were Arctic breeds (Alaskan Malamute or Siberian Husky) suggesting a predisposition in this type of dog.

Imaging diagnosis--FDG-PET/CT of a canine splenic plasma cell tumor

An 8-year-old Shih Tzu developed abdominal pain and hyperglobulinemia. A round splenic mass was noted radiographically and sonographically. The patient was evaluated by fluorodeoxyglucose positron emission tomography coupled with computed tomography (FDG-PET/CT). There was no evidence of metastasis or bone marrow involvement on PET/CT images. The standardized uptake value (SUV) of the splenic mass was increased over the reference range (SUV = 4.83). The patient was diagnosed as splenic extramedullary plasmacytoma through immunohistopathologic study. After the splenectomy, the globulin level normalized and the patient is alive without complications.

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.