Cutaneous lymphomatoid granulomatosis (angiotropic lymphoma) in a dog: immunophenotyping analysis

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.