| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Department of Veterinary Internal Medicine (H-MP, B-TK, D-IJ), Department of Veterinary Pathobiology, Small Animal Tumor Diagnostic Center (D-NH, G-SS, S-JL, J-YY, C-HY, J-HS), College of Veterinary Medicine, Konkuk University, Kwangjin-Ku, Seoul, Korea, and Department of Veterinary and Biomedical Sciences, University of Nebraska—Lincoln, Lincoln, Nebraska (ARD)
Abstract
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.
Key words: Dogs; immunohistochemistry; pulmonary Hodgkin's disease; pulmonary lymphomatoid granulomatosis.
Canine pulmonary lymphomatoid granulomatosis (PLG) is a rare pulmonary lymphoproliferative disease of dogs.1,4,7,8,9,10 It is characterized by multiple pulmonary nodules that consist of sheets of atypical lymphoreticular and plasmacytoid cells admixed with fewer mature eosinophils and lymphocytes.8 PLG has a predilection for the caudal lung lobes and frequently metastasizes to hilar lymph nodes.4 Canine PLG shows many similarities to human pulmonary Hodgkin's disease (PHD) and lymphomatoid granulomatosis (LYG).8
We report here the clinical, histopathologic, and immunophenotypic features of a dog diagnosed with PLG. Our results provide new insights into canine PLG, as well as confirm previous findings in this disease. A 10-month-old, intact female American Cocker Spaniel, kept exclusively indoors, was referred to the Veterinary Medical Teaching Hospital of Konkuk University, Seoul, Korea, because of a 1-week history of nonproductive, dry cough, serous nasal discharge, dyspnea, and lack of appetite. Physical examinations revealed that the dog was dyspneic and lethargic. On auscultation, harsh sounds and wheezes were detected in the left lung. A complete blood count showed abnormal leukocytosis (28.14 x 103/µl; reference range, 6–17 x 103/µl) and eosinophilia (5.628 x 103/µl; reference range, 0–1.4 x 103/µl). Thoracic radiography showed total consolidation of the left lung lobes with a diffuse interstitial pattern. The dog was treated with prednisolone and antibiotics. Seven months after the therapy, the dog died because of severe respiratory distress.
A necropsy revealed a complete consolidation of the left cranial lung lobe. The left lung contained a well-circumscribed mass (6 x 12 cm), which was firm on palpation. On cut section, the mass was white and contained multiple foci of necrosis and hemorrhage. Other organs, including the regional lymph nodes, were unremarkable in appearance. Tissues collected at necropsy were fixed in 10% neutral buffered formalin, embedded in paraffin, sectioned at 4 µm and stained with hematoxylin and eosin (HE).
For immunohistochemical (IHC) analysis, slides were incubated with antibodies to CD3, CD79a, CD20cy, CD15, and CD30, all purchased from DakoCytomation, Fine Life Science Co. (Seoul). The antibodies were diluted 1 : 100 (CD3 and CD20cy) or 1 : 200 (CD79a, CD15, and CD30). CD3 was assayed by using the 2-step Envision system-AP (alkaline phosphatase; DakoCytomation) and the others were assayed by using the Envision system-HRP (horseradish peroxidase; DakoCytomation), according to the manufacturer's instructions. To assay for colocalization of T and B cells, we used a double-labeling IHC technique for single-tissue sections.
Histopathologic examination showed a mixed population of atypical lymphoid cells and eosinophils in the pulmonary blood vessels. The atypical lymphoreticular cells, which consisted of monotypic and pleomorphic populations of anaplastic lymphoid cells, infiltrated angiocentrically with adjacent fibrinoid necrosis. Mitosis varied from 1 to 4 per high-power microscopic field (Fig. 1). The infiltrate also contained some large cells with large pleomorphic and binucleated nuclei resembling Reed-Sternberg cells in PHD. These clinical and histopathologic findings led to a diagnosis of PLG.
|
|
Canine PLG has features similar to those of human LYG and PHD.8 Human pulmonary LYG is characterized as a form of systemic vasculitis, as shown by prominent alteration of the vessels, coagulative necrosis, and the presence of angiocentric granulomatous infiltrates with neoplastic lymphocytes.2 Human pulmonary LYG is positive for CD3, CD20cy, and CD79a, but negative for CD15 and CD30.5 PHD includes polymorphous pulmonary infiltrates, composed of sheets of atypical and variable cells, including small mature lymphocytes, eosinophils, and plasma cells, as well as Reed-Sternberg cells.3 Reed-Sternberg cells are positive for CD15 and CD30, and neoplastic lymphocytes consist of mixed populations of CD3 and CD20cy positive cells.3
Histopathologically, the canine PLG described here has characteristics of human LYG, in that pleomorphic and anaplastic lymphoid cells had infiltrated into the vessels angiocentrically. Atypical lymphocytes positive for CD3, CD20cy, and CD79a, and Reed-Sternberg–like cells positive for CD15 and CD30 were also present. PLG in this dog was quite similar to human Hodgkin's disease immunophenotypically.
In summary, our IHC analysis showed that this dog with PLG had neoplastic B-cell coexpression, indicating that canine PLG is a pan-T-cell neoplasm strongly associated with neoplastic B-cell phenotype. We also found that canine PLG in this dog had clinical, histopathologic features similar to those of human LYG and immunophenotypic features similar to those of human PHD.
Acknowledgements
The study was supported by the Konkuk University Research Fund 2005. We thank Ms. R.-W. Jang for technical assistance. D.-N. Hwang and B.-T. Kang contributed to this paper as the co-first authors.
Accepted for publication May 31, 2007.
References
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Facebook
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
D. G. Rogers and V. A. Aliano Metastatic angioinvasive lymphoma (lymphomatoid granulomatosis) in a cat J Vet Diagn Invest, May 1, 2009; 21(3): 390 - 394. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |