Albanese, F.; Abramo, F.; Marino, M.; Massaro, M.; Marconato, L.; Minoli, L.; Martini, V.; Aresu, L. Feline and Canine Cutaneous Lymphocytosis: Reactive Process or Indolent Neoplastic Disease? Vet. Sci.2022, 9, 26.
Albanese, F.; Abramo, F.; Marino, M.; Massaro, M.; Marconato, L.; Minoli, L.; Martini, V.; Aresu, L. Feline and Canine Cutaneous Lymphocytosis: Reactive Process or Indolent Neoplastic Disease? Vet. Sci. 2022, 9, 26.
Cutaneous lymphocytosis (CL) is an uncommon and controversial lymphoproliferative disorder described in dogs and cats. CL is generally characterized by a heterogeneous clinical presentation and histological features that may overlap with epitheliotropic lymphoma. Therefore, its neoplastic or reactive nature is still debated. Here, we describe clinicopathological, immunohistochemical and clonality features of a retrospective case series of 19 cats and 10 dogs with lesions histologically compatible with CL. In both species, alopecia, erythema and scales were the most frequent clinical signs. Histologically, a dermal infiltrate of small to medium-sized lymphocytes, occasionally extending to the subcutis, was always identified. Conversely, when present, epitheliotropism was generally mild. In cats, the infiltrate was consistently CD3+; in dogs, a mixture of CD3+ and CD20+ lymphocytes was observed only in 4 cases. The infiltrate was polyclonal in all cats, while BCR and TCR clonal rearrangements were identified in dogs. Overall, cats had a long-term survival (median overall survival=1080 days) regardless of the treatment received, while dogs showed a shorter and variable clinical course, with no evident associations with clinicopathological features. In conclusion, our results support a reactive nature of the disease in cats, associated with prolonged survival; despite a similar histological picture, canine CL was associated with a more heterogeneous lymphocytic infiltrate, clonality results, and response to treatment.
Medicine and Pharmacology, Oncology and Oncogenics
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.