Angioinvasive lymphoma (lymphomatoid granulomatosis) in a cat, with cutaneous and ocular metastasis.

Lymphomatoid granulomatosis (LYG) is a rare variant of an angioinvasive T-cell lymphoproliferative disorder that primarily affects the lungs, with common sites of metastasis including the skin and subcutis. In humans, it is a B-cell lymphoproliferative disorder associated with Epstein-Barr virus infection. Our case is a 7-y-old, spayed female, domestic longhair cat that decompensated and was euthanized following an initial diagnosis of angioinvasive lymphoma from a skin biopsy. Autopsy revealed nodules in the lungs and subcutis, and corneal thickening and cloudiness. Histologic examination of cutaneous nodules, lungs, and eye showed similar angioinvasive cellular infiltrates and pattern to that of the original skin biopsy, consistent with a diagnosis of LYG. The neoplastic cells displayed CD3-positive immunoreactivity in the skin, eye, and lung, and PCR for antigen receptor rearrangement (PARR) showed T-cell clonality in all tissues tested. This is the third case of LYG to be reported in cats and is the only case in which PARR analysis and immunophenotyping immunohistochemical staining was performed. LYG with ocular involvement has not been reported previously in cats, to our knowledge. Our case demonstrates the necessity for considering LYG when presented with a cat with respiratory signs in conjunction with subcutaneous nodules and ocular lesions.

Pulmonary angiocentric lymphoma (lymphomatoid granulomatosis) in a donkey.

A 36-year-old donkey developed dyspnoea, pyrexia, hypoalbuminaemia and oedema. Following continued clinical deterioration the donkey was humanely destroyed. Grossly, there were numerous nodules (5-10mm) scattered throughout the lung. Microscopically, the lung was infiltrated by an angiocentric and bronchocentric to diffuse mixed population of small mature and atypical lymphocytes, histiocytes, plasma cells and fewer eosinophils. The infiltrate was composed of numerous small mature and fewer atypical CD3(+) T lymphocytes. Low numbers of CD20(+) and CD79a(+) B cells, some atypical, accompanied the T cells. These infiltrates were consistent with an angiocentric lymphoma and resembled lymphomatoid granulomatosis, an Epstein-Barr virus (EBV)-associated human tumour. Immunohistochemistry for EBV latent membrane protein and polymerase chain reaction analysis for equine gamma herpesvirus DNA were negative. To the authors' knowledge this is the first case of angiocentric lymphoma reported in a donkey and the first case of lymphomatoid granulomatosis-type disease in an animal in which possible concurrent infection with a gamma herpesvirus has been investigated.

Successful management with CHOP for pulmonary lymphomatoid granulomatosis in a dog.

A 3-year-old, spayed female miniature dachshund was presented for vomiting and anorexia. Thoracic radiographs and CT scan revealed abnormal pulmonary opacities at bilateral caudal lobe. Cytological analysis of the pulmonary mass revealed the presence of large lymphohistiocytic cells and small lymphocytes with occasional neutrophils and plasma cells. An open lung biopsy was performed and a diagnosis of pulmonary lymphomatoid granulomatosis (LYG) was made. The dog was administered CHOP based therapy (modified UW-25), and it survived for 1,022 days after admission. Immunohistochemistry revealed pulmonary lesions consisted of many CD79a positive B cells aggregation and proliferation with prominent angiocentric pattern. This was the first case of canine pulmonary LYG managed by CHOP chemotherapy.

A case of canine lymphomatoid granulomatosis with cutaneous lesions.

A 10-year-old, castrated, mixed-breed dog presented with a 1.5-month history of scattered, crateriform ulcers on the trunk and extremities. Some skin lesions appeared to regress spontaneously, but new lesions developed. Thoracic radiography revealed pulmonary consolidated lesions suggestive of tumor. A skin biopsy was performed for histopathological, immunohistochemical and clonality analyses. Histopathological examination of the cutaneous lesion revealed an intense infiltration of atypical lymphoid cells with some other cell populations around the blood vessels in the dermis. Atypical lymphoid cells were shown to be CD3-positive in the immunohistochemical analysis. The presence of clonally expanded T-cells was revealed by the clonal rearrangement of T-cell receptor gamma-chain gene. From the above findings, the dog was diagnosed with lymphomatoid granulomatosis.

Metastatic angioinvasive lymphoma (lymphomatoid granulomatosis) in a cat.

A subcutaneous mass removed from the right rear leg of a 17-year-old, spayed, female Domestic Shorthair cat was characterized histopathologically by granulomatous inflammation, sheets of large atypical lymphoid cells, and necrosis. The walls of the small and medium caliber blood vessels were invaded transmurally by atypical lymphoid cells. A diagnosis of angioinvasive lymphoma (AIL), or lymphomatoid granulomatosis, was made based on histopathologic findings. The cat was euthanized 2 months later because of recurrence of the mass and elevated serum alanine aminotransferase activity, and a necropsy was performed. The histopathologic lesion of AIL was seen in the skin and subcutis of the right rear leg, and neoplastic cell infiltrates were seen in adjacent skeletal muscle, right superficial inguinal lymph node, liver, and spleen. By immunohistochemistry, variable numbers of neoplastic cells expressed B-lymphocyte antigen 36 (BLA36) or cluster of differentiation (CD)3 markers, indicative of B- and T-cell lineages, respectively. Neoplastic cells were uniformly positive for vimentin and uniformly negative for cytokeratins and myeloid/histiocytic antigen. Although the cat had received a Rabies virus vaccine subcutaneously in the right rear leg 6 months earlier, the AIL lesion was not typical of vaccine-induced sarcomas. The AIL in this cat was unusual because the extrapulmonary metastases involved the skin and subcutis.

Pulmonary lymphomatoid granulomatosis in a dog: evidence of immunophenotypic diversity and relationship to human pulmonary lymphomatoid granulomatosis and pulmonary Hodgkin's disease.

We describe a 10-month-old, intact female American Cocker Spaniel with pulmonary lymphomatoid granulomatosis (PLG). On clinical examination, this dog presented with nonproductive dry cough, serous nasal discharge, dyspnea, and lack of appetite. Radiography showed a consolidated lesion in the left cranial lung lobe. Histopathologic examination showed a mixed population of atypical lymphoid cells that had infiltrated into the pulmonary blood vessels angiocentrically. The lymphocytes were CD3 positive, consistent with a pan-T-cell phenotype. The lymphoid cells in the lesion were also positive for CD20cy and CD79a, indicative of the presence of B cells. We also observed large Reed-Sternberg-like cells that were positive for CD15 and CD30, similar to observations in human pulmonary Hodgkin's disease (PHD). In conclusion, canine PLG in this Cocker Spaniel was associated with B and T cells, which is first identified in a case of canine PLG. It was histopathologically similar to human lymphomatoid granulomatosis and immunophenotypically similar to human PHD.

First cases of animal diseases published since 2000. 2. Cats.

In this second article of a series of papers listing first case reports of animal diseases published since 2000, the following nine cases of cat diseases are discussed: Congenital spongiform change in the brain stem nuclei. Enterococcus hirae enteropathy. Focal cerebral angiomatosis. Glomus tumor. Intraocular extramedullary plasmacytoma. Lens epithelial neoplasias. Phaeohyphomycosis due to Fonsecaea pedrosoi. Pulmonary lymphomatoid granulomatosis. Systemic amyloidosis in a Devon rex. After a short introduction, the bibliographical data, the abstract of the author(s) and some additional information derived from the article are given. The article will be regularly updated adding overlooked as well as new first reports.

Pulmonary lymphomatoid granulomatosis in a cat.

Pulmonary lymphomatoid granulomatosis was diagnosed in a 9-year-old castrated male domestic shorthair cat with a history of coughing, lethargy, and anorexia. Radiographic examination revealed multiple pulmonary opacities, consolidation of left lung lobes, and enlarged tracheobronchial lymph nodes. Cytologic examination of impression smears of abnormal pulmonary tissue revealed erythrocytes, lymphocytes, and macrophages, with scattered atypical lymphocytes and binucleate cells. Histopathologic evaluation of abnormal lung tissue revealed multiple, coalescing, densely cellular nodules composed of anaplastic and pleomorphic lymphocytes, with scattered binucleate and multinucleate cells. Marked infiltration and effacement of bronchiolar and vascular smooth muscle were present. These features are characteristic of lymphomatoid granulomatosis. To the authors' knowledge, this is the first report of pulmonary lymphomatoid granulomatosis in a cat.

Canine lymphomatoid granulomatosis: an immunophenotypic analysis of three cases.

Three dogs had a history of multiple progressive lesions affecting the skin, subcutis or skeletal muscles. The lesions developed over a period of several months, and each case demonstrated late cardiopulmonary complications. Post-mortem examination revealed multicentric, angio-destructive, lymphohistiocytic, proliferative lesions typical of the rare disorder lymphomatoid granulomatosis. Immunohistochemical examination demonstrated variable CD3 antigen expression by the atypical cell population in two of the three cases. This provides the first evidence that canine lymphomatoid granulomatosis may be a form of atypical T-cell lymphoma similar to the comparable disorder that occurs in man.

A canine case of profound granulomatosis due to Paecillomyces fungus.

A 5-year-old dog showed remarkable edematous swelling of the left hock with lameness and local cellulitis, and paecillomyces fungus was isolated from ulcerative lesion of the hock joint and mediastinum. At autopsy severe effusive pleuritis was shown and numerous necrotizing and granulomatous lesions with fungal elements were seen in the liver, pancreas, kidney and mediastinal lymph nodes.

Pulmonary lymphomatoid granulomatosis in seven dogs (1976-1987).

Seven dogs with pulmonary lymphomatoid granulomatosis were reviewed. The disease occurred in six large-breed and one small-breed dogs. The dogs were five to 14 years old (mean, 8.4; median, 7), and four of seven dogs were males. Three dogs had been previously treated with adulticide therapy for canine dirofilariasis. Clinical histories included a progressive respiratory disease characterized by varying degrees of cough, dyspnea, exercise intolerance, and weight loss. Thoracic radiographic features included hilar lymphadenopathy, pulmonary masses of varying sizes, and mixed pulmonary patterns of lobar consolidation with ill-defined interstitial and alveolar pulmonary infiltrates. Cardiovascular changes compatible with chronic dirofilariasis were present in three dogs. The clinical course was usually progressive and fatal. The survival time ranged from six days to four years (mean, 12.5 mos; median, 3 mos). Gross and histologic features included mass lesions with areas of necrosis that replaced normal pulmonary architecture. Cytologically, these lesions were characterized by infiltration with pleomorphic, angioinvasive mononuclear cells that often resulted in vascular obliteration. The infiltrating cells resembled large lymphoid cells that possessed large hyperchromatic nuclei and small amounts of cytoplasm. Systemic lymphoid neoplasia with peripheral lymphadenopathy was diagnosed in two dogs. In both cases, lymph-node cytology was similar to the cellular infiltrates found in the lungs and consistent with a diagnosis of lymphomatoid granulomatosis. These features are compared with previously reported cases of canine lymphomatoid granulomatosis and those features identified in a similar disease described in man.

A syndrome resembling lymphomatoid granulomatosis in the dog.

Lymphomatoid granulomatosis (LYG) was diagnosed in seven dogs. Most of the affected dogs were young to middle-aged, and there was no breed or sex predilection. Basophilia was detected in six of the seven dogs. Radiographic abnormalities included lung lobe consolidation or pulmonary mass lesions, as well as abnormally large tracheobronchial lymph nodes. Histologic changes included angiocentric and angiodestructive pulmonary infiltrates characterized by large lymphoreticular and plasmacytoid cells as well as normal lymphocytes, eosinophils, and plasma cells. Five dogs were treated with combination chemotherapy, and three had a complete response to treatment.

Utilization of cytoplasmic lysozyme immunoreactivity as a histiocytic marker in canine histiocytic disorders.

Immunoreactive lysozyme was readily detectable in canine histiocytic disorders including systemic histiocytosis, malignant histiocytosis and granulomatous panniculitis. Lysozyme was less reliable as a histiocytic marker in cutaneous histiocytoma; forty percent of these tumors were negative for lysozyme expression. The marked heterogeneity in lysozyme expression in cutaneous histiocytoma may indicate that a proportion of these tumors show relatively primitive histiocytic differentiation and do not express lysozyme. Alternatively, this same proportion may exhibit a phenotype akin to cutaneous Langerhans cells which do not contain lysozyme. Lysozyme was not detectable in the tumor cells in lymphomatoid granulomatosis, atypical cutaneous histiocytoma, and histiocytic lymphosarcoma. Other evidence that these three disorders do not represent true histiocytic proliferative disorders is discussed.

Systemic histiocytosis of Bernese mountain dogs.

A histiocytic proliferative disorder was identified in six closely related Bernese mountain dogs. Clinical signs included anorexia, weight loss, stertorous respiration, and conjunctivitis with marked chemosis. Multiple cutaneous nodules were distributed over the entire body but were especially prevalent in the scrotum, nasal apex, nasal planum, and eyelids. Lesions consisted of perivascular infiltrates of large histiocytes as well as minor populations of lymphocytes, neutrophils, and eosinophils. Histiocytes were further characterized by enzyme histochemistry and electron microscopy. Necropsy examinations of four dogs revealed that the histiocytic infiltrates were widespread and involved skin, lung, liver, bone marrow, spleen, lymph nodes, kidneys, testes, orbital tissues, and others. However, skin and peripheral lymph nodes were more consistently involved. The disease course was punctuated by remissions and relapses not clearly influenced by conventional therapeutic measures. Preliminary results of an experimental therapeutic regimen involving administration of bovine thymic extracts in two dogs are present. The relationship of the disorder to other human and canine histiocytic proliferative disorders is discussed.