BACKGROUND: Evolution of indolent to aggressive lymphoma has been described in dogs but is difficult to distinguish from the de novo development of a second, clonally distinct lymphoma. Differentiation of these scenarios can be aided by next generation sequencing (NGS)-based assessment of clonality of lymphocyte antigen receptor genes. CASE PRESENTATION: An 8-year-old male intact Mastiff presented with generalized lymphadenomegaly was diagnosed with nodal T zone lymphoma (TZL) based on cytology, histopathology, immunohistochemistry and flow cytometry. Thirteen months later, the dog re-presented with progressive lymphadenomegaly, and based on cytology and flow cytometry, a large B cell lymphoma (LBCL) was diagnosed. Sequencing-based clonality testing confirmed the de novo development of a LBCL and the persistence of a TZL. CONCLUSIONS: The occurrence of two distinct lymphoid neoplasms should be considered if patient features and tumor cytomorphology or immunophenotype differ among sequential samples. Sequencing-based clonality testing may provide conclusive evidence of two concurrent and distinct clonal lymphocyte populations, termed most appropriately "composite lymphoma".

• MeSH
• alkylační protinádorové látky aplikace a dávkování   terapeutické užití   MeSH
• chlorambucil aplikace a dávkování   terapeutické užití   MeSH
• difúzní velkobuněčný B-lymfom komplikace   patologie   veterinární   MeSH
• hormonální protinádorové látky aplikace a dávkování   terapeutické užití   MeSH
• lymfom T-buněčný komplikace   patologie   veterinární   MeSH
• nemoci psů patologie   MeSH
• prednison aplikace a dávkování   terapeutické užití   MeSH
• psi MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH