Progression of a solitary, malignant cutaneous plasma-cell tumour to multiple myeloma in a cat

An 11‐year‐old male domestic shorthair cat was examined because of a soft‐tissue mass on the left tarsus previously diagnosed as a malignant extramedullary plasmacytoma. Findings of further diagnostic tests carried out to evaluate the patient for multiple myeloma were negative. Five months later, the cat developed clinical evidence of multiple myeloma based on positive Bence Jones proteinuria, monoclonal gammopathy and circulating atypical plasma cells. This case represents an unusual presentation for this disease and documents progression of an extramedullary plasmacytoma to multiple myeloma in the cat.     

Choroidal melanocytoma in a cat

An 11-year-old male, neutered European cat was presented for anisocoria due to pupillary dilation in the right eye. Ophthalmic findings were restricted to this eye and consisted of a raised, darkly pigmented, retrolental mass associated with retinal detachment. Ultrasonography identified the mass lesion protruding into the vitreous cavity from the posterior pole of the eyeball and confirmed the detachment of the retina. A tentative diagnosis of an intraocular tumor was made. Radiographic evaluation and retromandibular lymph node cytology did not reveal evidence of distant metastasis. Orbital exenteration of the affected eye was performed and the tumor was diagnosed as a choroidal melanocytic tumor with no criteria of malignancy (melanocytoma). The cat died 5 months later from renal lymphoma, and necropsy did not detect metastasis of the melanocytic tumor. To our knowledge this is the first reported case of feline choroidal melanocytoma.     

Intraocular melanoma with multiple metastases in a cat

An 11-year-old cat with an intraocular melanoma was treated for 2 years for the secondary effects of the tumor (glaucoma, exposure keratitis) before enucleation was required. One year after enucleation, the cat was examined because of labored breathing. The cat was thin, appeared depressed, and had signs of respiratory compromise secondary to pleural effusion. Treatment was not instituted, and the cat was euthanatized. Metastasis of the primary melanoma to the lungs, pericardium, parietal pleura, mediastinum, hilar lymph nodes, diaphragm, liver, and omentum was confirmed at necropsy. Intraocular melanomas in the cat have been implicated to have a greater malignant potential than those in the dog; however, few cases have been reported with long-term follow-up information.     

Association between lymph node size and metastasis in dogs with oral malignant melanoma: 100 cases (1987-2001)

OBJECTIVE: To determine the association between lymph node size and metastasis and to assess measurement of lymph node size as an accurate and reliable means of tumor staging in dogs with oral malignant melanoma. DESIGN: Retrospective study. ANIMALS: 100 dogs with histologically confirmed oral malignant melanoma. PROCEDURE: Clinical records for dogs with oral malignant melanoma were reviewed. Data regarding size and results of cytologic or histologic examination of lymph nodes were evaluated. The association between lymph node size and metastasis was determined. RESULTS: Forty-seven (47%) dogs, of which 23 (49%) had enlarged mandibular lymph nodes, had no cytologic or histologic evidence of metastasis. Of 53 (53%) dogs with cytologic or histologic evidence of mandibular lymph node metastasis, 37 (70%) had enlarged mandibular lymph nodes, and 16 (30%) had mandibular lymph nodes of normal size. Overall, 16 of the 40 (40%) dogs with normal-sized lymph nodes had microscopic evidence of metastatic disease. Sensitivity and specificity of lymph node size as a predictor of metastasis were 70 and 51%, respectively, and the positive and negative predictive values were 62 and 60%, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Although a significant relationship was identified between lymph node size and metastasis to the lymph node, this association did not appear strong enough to be clinically relevant. Results suggest that lymph node size alone is insufficient for accurate clinical staging of oral malignant melanoma in dogs; cytologic or histologic examination of regional lymph nodes should routinely be performed, regardless of size of those nodes.     

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.     

Clinical behavior of intraocular teratoid medulloepithelioma in two‐related Quarter Horses

The objective of this paper is to describe clinical behavior, histopathologic features, and immunohistochemical staining of two‐related horses with intraocular teratoid medulloepithelioma. Two‐related Quarter Horses with similar intraocular masses presented to the UF‐CVM Comparative Ophthalmology Service for evaluation and treatment. The first horse, a 3‐year‐old gelding, had glaucoma and a cyst‐like mass in the anterior chamber. Enucleation was performed. Histopathology revealed a teratoid medulloepithelioma. The tumor was considered to be completely excised. Fifteen months later, the gelding presented with swelling of the enucleated orbit and local lymph nodes with deformation of the skull. Cytology revealed neuroectodermal neoplastic cells. Necropsy confirmed tumor metastasis. Six weeks later, a 9‐year‐old mare, a full sibling to the gelding, presented for examination. An infiltrative mass of the iris and ciliary body was found that extended into the anterior, posterior, and vitreal chambers. Uveitis was present, but secondary glaucoma was not noted. Enucleation was performed and the histopathologic diagnosis was also teratoid medulloepithelioma. The mare has had no recurrence to date, 2 years following enucleation. Metastasis of intraocular teratoid medulloepithelioma is possible. Staging is recommended in cases where the diagnosis of teratoid medulloepithelioma is confirmed. Surveillance of full siblings is recommended until more information regarding etiology is known.     

Hemophagocytic syndrome in a cat with multiple myeloma

An 11‐year‐old, castrated male, Domestic Medium Hair cat was presented to the University of Florida Small Animal Hospital with a 2‐week history of upper respiratory infection and increased serum globulins, as reported by the referring veterinarian. Physical examination was unremarkable other than melanosis of the left iris, with no evidence of ocular, nasal, or respiratory disease. Laboratory abnormalities included moderate nonregenerative anemia, mild leukopenia, mild hyperfibrinogenemia, severe hyperglobulinemia, mild hypoalbuminemia, and hypocholesterolemia. Abdominal radiographs and ultrasonographic examination revealed mild splenomegaly with no other abnormalities. Thoracic radiographs revealed no abnormalities. Cytologic evaluation of fine‐needle aspirates from the spleen, liver, and bone marrow revealed numerous plasma cells and many vacuolated macrophages exhibiting marked phagocytosis of mature erythrocytes and platelets, occasionally metarubricytes and leukocytes, and rarely plasma cells. The cytologic interpretation was multiple myeloma and associated hemophagocytic syndrome (HPS). Serum protein electrophoresis revealed a monoclonal gammopathy, providing further evidence for a multiple myeloma. To the authors' knowledge, this is the first report of HPS secondary to neoplasia in a cat.     

Presumed primary ocular lymphangiosarcoma with metastasis in a miniature horse

A 7‐year‐old, 153.0‐kg American Miniature mare presented for evaluation of keratoconjunctivitis of the right eye (OD). A superior palpebral conjunctival mass and stromal keratitis were diagnosed. The incisional biopsy diagnosis was a presumptive corneal hemangiosarcoma. Transpalpebral enucleation was performed, and histopathologic evaluation confirmed angiosarcoma of the conjunctiva, cornea, and extraocular muscles. The horse developed progressive epistaxis and orbital swelling following surgery. A systemic workup was performed 3 months after enucleation, revealing regrowth within the orbit and marked cranial cervical lymphomegaly, suggestive of metastasis. Humane euthanasia was performed, and necropsy confirmed a locally invasive periorbital tumor with metastasis to the submandibular tissue, submandibular lymph node, and thoracic inlet. Histopathologic evaluation of necropsy specimens revealed polygonal to spindle neoplastic cells lining neoplastic vascular channels lacking erythrocytes. Immunohistochemically, the neoplastic cells labeled strongly positive for PROX‐1, vimentin, CD‐31, VEGF, weakly positive for factor VIII‐related antigen, and negative for collagen IV. Based on the clinical, histological, and immunohistochemical features of this tumor, a primary ocular lymphangiosarcoma with metastasis was diagnosed.     

Aortic body chemodectoma causing pulmonary oedema in a cat

A seven-year-old male domestic shorthaired cat was presented with persistent dyspnoea. Thoracic radiography and echocardiography revealed pulmonary oedema and a mass at the base of the heart. At necropsy the mass was found to be an aortic body chemodectoma that had metastasised to the sternal lymph node. This is a rare tumour in the cat, the third reported case where there was evidence of metastasis, and only the second reported case where there was evidence of lymphocytic infiltration of the primary tumour. Pulmonary oedema is an unusual presentation of this tumour in the cat.     

Lymph node staging of oral and maxillofacial neoplasms in 31 dogs and cats

A retrospective study was performed to report the histologic examination results of regional lymph nodes of dogs and cats with oral or maxillofacial neoplasms. Twenty-eight dogs and 3 cats were evaluated. Histologic examination results of standard and serial tissue sectioning of regional lymph nodes were recorded. When available, other clinical parameters including mandibular lymph node palpation, thoracic radiographs, and pre- and postoperative fine needle aspiration of lymph nodes were compared with the histologic results. Squamous cell carcinoma, fibrosarcoma, and melanoma were the most common neoplasms diagnosed in dogs. Squamous cell carcinoma and fibrosarcoma were diagnosed in cats. Of the palpably enlarged mandibular lymph nodes, 17.0% had metastatic disease histologically. Radiographically evident thoracic metastatic disease was present in 7.4% of cases. Preoperative cytologic evaluation of the mandibular lymph node based on fine needle aspiration concurred with the histologic results in 90.5% of lymph nodes examined. Postoperative cytologic evaluation of fine needle aspirates of regional lymph nodes concurred with the histologic results in 80.6% of lymph nodes examined. Only 54.5% of cases with metastatic disease to regional lymph nodes had metastasis that included the mandibular lymph node. Serial lymph node sectioning provided additional information or metastasis detection. Cytologic evaluation of the mandibular lymph node correlates positively with histology, however results may fail to indicate the presence of regional metastasis. Assessment of all regional lymph nodes in dogs and cats with oral or maxillofacial neoplasms will detect more metastatic disease than assessing the mandibular lymph node only.     

Erythrophagocytic multiple myeloma in a cat

A 7-year-old neutered male domestic shorthair cat was presented to the Veterinary Medical Teaching Hospital at the University of Georgia for further evaluation of a suspected osteolytic lesion of the left 10th rib. Results of a CBC and biochemistry profile revealed mild nonregenerative anemia, hyperproteinemia, hyperglobulinemia, and hypercalcemia. Serum protein electrophoresis was consistent with a monoclonal gammopathy. Marked proteinuria with an increased urine protein to creatinine ratio was found. Cytologic examination of the liver, spleen, and bone marrow revealed numerous plasma cells, many of which were erythrophagocytic. Within the bone marrow, the plasma cells contained phagocytosed metarubricytes in addition to phagocytosed erythrocytes. A diagnosis of erythrophagocytic multiple myeloma was made and treatment with prednisone and melphalan was begun. Four weeks after presentation, the cat was euthanized due to clinical deterioration. A complete necropsy was performed. The distal one-third of the left 10th rib was completely absent. Histologically, there was no evidence for osteolysis or neoplastic cells in the remaining portion of the rib. However, large sheets of plasma cells were found infiltrating the spleen and bone marrow. Moderate erythrophagocytosis by the plasma cells was observed in both organs. The plasma cells, including the erythrophagocytic cells, were positive for CD79alpha by immunohistochemical staining. Erythrophagocytosis by plasma cells as a cause of anemia is uncommon in people with multiple myeloma and is rare in animals. To our knowledge, this is the first report of erythrophagocytic plasma cells in a cat with multiple myeloma.     

Gastric extramedullary plasmacytoma in a dog.

A 10-year-old mixed-breed dog was examined because of a 6-week history of daily vomiting and sporadic diarrhea. On gastroscopy, a crateriform mass was observed on the greater curvature of the stomach. Partial gastrectomy and lymphadenectomy of a large mesenteric lymph node was performed. Gastric plasmacytoma with lymph node metastasis was diagnosed by histologic and immunoperoxidase methods, and chemotherapy was initiated with doxorubicin hydrochloride and diphenhydramine hydrochloride. The dog remains clinically normal 30 months after initial diagnosis. Although gastric plasmacytomas are rare in dogs, long-term survival appears to be better with this disease than with other types of gastric neoplasia.     

ULTRASONOGRAPHIC EXAMINATION OF CERVICAL MASSES IN THE DOG AND CAT

The ultrasonographic appearance of clinically undifferentiated neck masses for which a definitive diagnosis was eventually obtained in nineteen dogs and one cat is presented in this report. Multiple lesions were seen ultrasonographically in 4 dogs and no cervical abnormalities were seen in 2 dogs resulting in 22 lesions in 20 annuals. Of 7 benign lesions, there were 2 patients with reactive lymph nodes from a regional inflammatory process, and 1 patient each with primary pyogranulomatous lymphadenitis, arteriovenous malformation, foreign body granuloma, cellulitis, and hematoma. Of 15 malignant lesions, 7 were thyroid carcinomas, 3 were lymphomas with submandibular and cervical lymph node enlargement, 3 were lymph node enlargements associated with regional metastasis of malignant tumors, one was a leiomyosarcoma and one was a carotid body tumor. One dog with a diffuse soft tissue swelling of the ventral cervical region had only slight asymmetry of the thyroid lobes on ultrasound examination and no abnormalities of the neck at post mortem. A second dog examined with ultrasound 4 months after surgical removal of a carotid body tumor had no evidence of tumor recurrence. Ultrasonographic examination provided information regarding the character of the lesions, the tissue or organ of origin, and invasion into other anatomic structures. Ultrasound examination in conjunction with fine needle or tissue biopsy provided a definitive diagnosis in those animals in which biopsies were performed.     

Hypereosinophilic syndrome in cats: a report of three cases.

The clinical, clinicopathological and pathological findings in three cats with hypereosinophilic syndrome are described. The cats chosen for the study had marked eosinophilia and evidence of tissue infiltration by eosinophils. Necropsies were performed on two cats, biopsy and blood samples were provided for the third cat. At necropsy, there was diffuse reddening of femoral bone marrow with ulceration and thickening of the duodenum. The livers had an enhanced lobular pattern with multiple, white, 1-3 mm nodules throughout the parenchyma. One cat had splenomegaly and the other had several enlarged, white, firm lymph nodes. Histopathologically, there was eosinophil infiltration of intestine, lymph nodes, liver, spleen, adrenal medulla and beneath the endocardium. Ultrastructurally, the eosinophils from lymph node and bone marrow of cat II were morphologically normal. The rigid criteria for eosinophilic leukemia were not fulfilled by these cases and the etiology of the eosinophilia in each case is not known. Possible pathogenic mechanisms are discussed.     

Intraocular hemorrhage in a goat with thrombocytopenia and metastasis of an adenocarcinoma in the iris

This case report describes the findings in a 10-year-old goat with metastasis of an adenocarcinoma in the iris. Two weeks before admission, the owner had noticed blepharospasm of the left eye. Clinical examination by the referring veterinarian revealed unilateral intraocular hemorrhage. The goat was referred to our clinic for further work-up. The rectal temperature was 40 degrees C. The most important haematological result was severe thrombocytopenia. There was mild corneal oedema of the left eye. Approximately 75 per cent of the anterior chamber was filled with non-coagulated blood. The fluid in the anterior chamber dorsal to the blood was cloudy, and the corpora nigra could not be seen clearly. All other internal parts of the eye could not be seen. Ultrasonography of the left eye confirmed cloudiness of the anterior chamber and revealed moderate thickening of the iris. The right prescapular lymph node was markedly enlarged. Cytological examination of a fine needle aspirate of the lymph node showed a mixed population of neoplastic cells. Based on immunohistochemical evaluation of the cells metastasis of a carcinoma was diagnosed. The goat was subjected to euthanasia, and a postmortem examination was carried out. The anterior chamber of the left eye contained blood, and the iris was thicker than normal and adhered to the posterior surface of the cornea. There were neoplastic alterations in the iris, the oesophagus, the lung lobes, the liver, the kidney and in the prescapular, retropharyngeal, mediastinal and hepatic lymph nodes. Histologically, a diagnosis of carcinoma was confirmed, but the origin of the tumour could not be determined.     

Bilateral anterior segment dysgenesis in a 7-week-old domestic shorthaired cat

A 7-week-old, intact, female domestic shorthaired cat was presented to the Atlantic Veterinary College (AVC) Ophthalmology service for a 1-week history of buphthalmia in the left eye and bilateral elevated intraocular pressures. Ocular examination revealed bilateral non-visual glaucomatous eyes. Bilateral enucleations were performed without complications and histopathology revealed anterior segment dysgenesis of varying degrees in both eyes.Key clinical message:Anterior segment dysgenesis is a developmental condition that can result in primary congenital glaucoma for which the best course of treatment is enucleation.     

Presumed post‐traumatic ocular chondrosarcoma with intrathoracic metastases in a cat

An indoor‐only, 5‐year‐old, spayed female domestic shorthair cat presented for an ophthalmic examination of the left eye. An intraocular tumor with secondary glaucoma and blindness was diagnosed; the globe was enucleated and sent for histopathological examination. Gross examination revealed a solid white mass filling the entire vitreous space and replacing the iris and ciliary body. The lens and retina appeared to be similarly replaced by the neoplasm. Histological examination revealed a complete loss of the internal ocular structures, with a ruptured capsule as the only remnant of the lens within an extensive malignant mesenchymal neoplastic cell proliferation. The cells were polygonal, with well‐defined cytoplasmic borders and abundant weakly basophilic cytoplasm, embedded within the islands of chondroid matrix. No neoplastic invasion of the sclera was apparent. The animal died 6 months after the enucleation due to respiratory distress. Gross examination revealed numerous firm, white to tan nodular masses with smooth to mildly irregular surfaces dispersed throughout the parietal pleura, thoracic surface of the diaphragm, tracheobronchial and mediastinal lymph nodes, pericardium, and lungs. On cross‐section, the neoplastic nodules were solid and variably translucent, resembling hyaline cartilage. Histologically, these nodules were similar to the neoplasm identified earlier in the left globe. Metastasis of post‐traumatic ocular chondrosarcoma has not yet been described in cats. This is therefore believed to be the first report of metastases of this type of neoplasm in cats. This case adds to the limited set of data on the outcome of this type of tumor.     

Orbital plasmacytoma in a cat

An Abyssinian cat presented with epistaxis, melaena and retinal vascular changes. Plasma protein levels were markedly elevated and a monoclonal gammopathy was present on serum protein electrophoresis. Based on these laboratory findings, hyperviscosity syndrome was assumed to be responsible for the clinical signs. The cat responded initially to fluid therapy, but relapsed and then developed unilateral exophthalmia. The animal was euthanased and an extramedullar plasmacytoma of the right orbit was diagnosed at postmortem examination.     

Vertebral plasma cell tumors in 8 dogs

The case histories of 8 dogs with spinal pain and neurologic deficits associated with vertebral plasma cell tumor are reviewed. Four dogs had solitary plasmacytoma, 3 had multiple myeloma, and 1 dog had 2 vertebral lesions with no evidence of disseminated disease. Four dogs were treated: 2 with multiple myeloma received chemotherapy only and survived 17 and 26 months, respectively. Two dogs with solitary plasmacytomas of the spine had chemotherapy and radiotherapy: the 1st survived 4 months and was euthanized after developing radiation myelopathy; the 2nd survived 65 months before developing multiple myeloma. The diagnosis of solitary plasmacytoma of the spine versus multiple myeloma is discussed.     

Metastatic synovial cell sarcoma in two cats

Synovial cell sarcoma (SCS) with metastasis to the regional lymph node was diagnosed in two cats. Synovial cell sarcomas are rare in cats and metastatic SCS has not previously been reported. In both cases, treatment consisted of limb amputation and adjuvant doxorubicin. Local tumour recurrence and pulmonary metastases were diagnosed in one cat 316 days postoperatively. This cat died of chronic renal failure 444 days after limb amputation. The second cat died of an acute pulmonary thromboembolism 41 days postoperatively without evidence of local tumour recurrence or metastatic disease.