Damla HAKTANIR (1), Evrim EGEDEN (2), E. Handan ZEREN (3), Aydın GÜREL (1)
1. Istanbul University, Faculty of Veterinary Medicine, Department of Pathology, Avcilar, Istanbul
2. Ada Veterinary Polyclinic. Sülün Sokak, No: 14 1. Levent 34330 Besiktas, Istanbul
3. Department of Pathology, Faculty of Medicine, Acıbadem University, Ataşehir, İstanbul, Turkey
Introduction and Aim
Cutaneous lymphoma is a neoplasia rarely seen in cats. Nonepitheliotropic cutaneous lyphoma is its most common form and generally is of T cell origin. In this case we are going to present clinical, histopathological and immunohistochemical characteristics and treatment of nonepitheliotropic cutaneous lyphoma which was seen as extensive skin lesions in a cat.
Material and Method
9 year old, female tabby cat was brought into Ada Veterinary Polyclinic with hyperemic, itchy, non-necrotic, non-keratinized, extensive skin lesions with alopecia particularly on hind extremities and abdomen area. Patient was administered corticosteroids to decrease inflammation. Response to oral prednisolone was low, response to subcutaneous methylprednisolone acetate application was better. Smear preparation was stained with May-Grünwald Giemsa for cytological examination. Punch biopsy sample was taken from the lesion for histopathological examination. Tissue sample was fixed in 10% formaldehyde buffered solution. Then samples were embedded in paraffin blocks after routine tissue processing. Paraffin blocks were sectioned in 3-4 μm width, stained in hematoxylin and eosin dye and examined under light microscope. For a immunohistochemical examination of the histopathological diagnosis, tissue sections were stained with Ventana-Benchmark XT method by using Pan-T cell markers CD3 and CD5; Pan-B cell marker CD20 and Ki-67 antibody.
hyperemic, itchy, nonnecrotic, non-keratinized, extensive skin lesions with alopecia
Findings
Cytopathology
Smear preparations from the lesions revealed few polymorphonuclear, inflammatory cells as well as many small atypical cell groups with narrow cytoplasms, ovoid, hyperchromatic nuclei, some of them notched.
Smear preparations from the lesions, pleomorphic, atypical lymphoid cells. May-Grünwald staining.
Histopathology
Neoplastic tissue showing follicular structure infiltrated in the deep dermal area and subcutaneous fat tissue consisted of small, mature, atypical lymphoid cell infiltrations with hyperchromatic nuclei. There was no epidermal invasion.
From left to right:
A. Neoplastic tissue showing follicular structure in the dermis. H&E
B. No neoplastic invasion in the epidermis. H&E
C. Hyperchromatic neoplastic cells infiltrating collagen bundles in the deep dermal tissue. H&E
Immunohistochemistry
90% of the cell population gave a positive reaction to CD3 antibody. There was no staining in CD5 and CD20 antibodies. The Ki-67 proliferation index of the neoplastic tissue was 5-10%.
From left to right:
A. Positive reaction for CD3 antibody in 90% of the cell population. Ventana-Benchmark XT method.
B. Ki-67 proliferation index 5-10%. Ventana-Benchmark XT method.
Discussion and Results
Considering clinical, histopathological and immunochemical characteristics, diagnosis was T cell nonepitheliotropic cutaneous lymphma. There was no visceral organ retention. Cytopathological findings confirmed the diagnosis. It is also reported in the literature that cytopathology is a good diagnostic tool in lymphomas. Although lomustine monotherapy is recommended as the first protocol in cutaneous T cell lymphomas, the prognosis of the disase is bad in dogs and variable in cats. That is why it is our opinion that cats should be administered protocols with fewer side effects. This patient was administered the cat gastrointestinal lymphoma protocol of prednisolone (DELTACORTRIL tb, po, 1,5 mg/kg q24h)+clorambucil (LEUKERAN tb, po, 2 mg, q72h) and the skin lesions showed regression on the 20. day of treatment. Patient suffered from no side effects. Although encountered rarely, we are of the opinion that chronic progressive skin lesions in cats should ve evaluated along with endocrinopathy, ectoparasitic infestations, and autoimmune dermatosis for differential diagnosis.
20th day of treatment (prednisolone + chlorambucillin)
