Anaplastic Large T-Cell Lymphoma in the Intestine of Dogs

Abstract

Anaplastic large T-cell lymphoma (ALTCL) is a rare subtype of non-Hodgkin T-cell lymphoma that occasionally occurs in the gastrointestinal tract of humans. Enteropathy-associated T-cell lymphoma (EATL) type 1 is the most common type of intestinal lymphoma in dogs, and ALTCL has not previously been reported in the intestinal tract of dogs. Thirteen dogs with intestinal masses diagnosed as intestinal lymphoma with anaplastic morphology were reviewed. Clinical data, including treatment protocols, were available for 11 cases. Immunohistochemistry for CD3, CD20, and CD30 was performed for all cases in addition to PCR for Antigen Receptor Rearrangements (PARR) for assessment of clonality. Eight (62%) of the cases presented with intestinal perforation, and all cases had 1 or more masses arising from the small intestine. Histologically, all cases were characterized by transmural infiltrates of large, CD3-positive and frequently CD30-positive cells. Neoplastic T cells had marked anisocytosis and anisokaryosis, prominent nucleoli, and occasionally indented to reniform nuclei. There was abundant necrosis and inflammation with occasional vascular invasion within neoplastic masses. All cases had a monoclonal T-cell receptor γ gene rearrangement. The median survival time was 5 days, with 1 dog surviving 2 years after the initial diagnosis. ALTCL can occur as an aggressive transmural lymphoma in the gastrointestinal tract of dogs and commonly causes intestinal perforation. ALTCL can be differentiated from EATL type 1 and might have implications for accurate prognostication and selection of therapeutic options in the future.

Histopathological features and immunophenotyping of canine transmural gastrointestinal lymphoma using full-thickness biopsy samples

“…ALCL is a rare type of lymphoma in humans that is characterized by large cells with severe nuclear pleomorphism and CD30 expression. 33 A previous study revealed the expression of CD30 in canine intestinal ALCL 32 ; 3 cases of ALCL expressed CD30. In addition, ALCL showed a significantly higher Ki67 index than eosinophil-dominant mixed inflammatory PTCL and PTCL-NOS.…”

“…In addition, ALCL showed a significantly higher Ki67 index than eosinophil-dominant mixed inflammatory PTCL and PTCL-NOS. Canine intestinal ALCL is reported to have a poor prognosis with an aggressive clinical course, 32 but information on clinical outcomes was not available in the present study.…”

The Genetic and Molecular Basis for Canine Models of Human Leukemia and Lymphoma

“…The latter is classified as a very rare form of human PTCL in the WHO system, but it is discussed separately from PTCL in veterinary medicine because it is common, and clearly distinct from the other types-dogs are older, the disease is indolent and often not treated, and the defining feature of T zone lymphoma is loss of CD45 expression (7, 70), which is not seen in other canine lymphomas. Anaplastic large cell lymphoma (71) and angioimmunoblastic T cell lymphoma (AITL) are diagnosed rarely if at all in dogs (5).…”

Flow Cytometry in the Diagnosis of Canine T-Cell Lymphoma

“…Enteropathy-associated T Cell Lymphoma (EATL) is generally investigated via immunohistochemistry and shows positivity to CD3 and occasionally to CD30, a marker of anaplastic lymphoma in humans (40). In rare instances, aberrant co-expression of B cell antigen CD20 is possible (41).…”