An 11 year-old, female cross-breed cat referred to the University of Ankara, Faculty of Veterinary, Department of Internal Medicine was included in the present paper.

According to the anamnesis, it was reported that the patient had a small lesion approximately three years ago, so far grew up despite antibacterial and antifungal therapy and continued to grow despite two doses of glucocorticoid therapy three months ago, had inappetite for the last month and aggressive behavior.

At the clinical examination; a mass changing the normal structure of the invased tissues completely on paranasal area, in dark pink-purple colored, tough-elastic consistent on papation and completely surrounding nose and upper lip was observed. The body temperature, respiratory and heart rate were in physiological levels. At haematological examination, erythrocyte 6.9 x10⁶/ml, leukocyte 12x10³/ml, PCV 32%, Hb 20 mg/dl, neutrophil 87%, lymphocyte 11%, monocyte 2% were detected.

Biopsy specimens, taken from the areas of lesions, histopathologically revealed, neoplastic progress showing ulceration on surface, lymphoid infiltration rich in partial irregular nuclear contour, diffusely covering opulent the dermis and a diagnose of high grade lymphoma was made.

Within the presentation of this case the aim was to emphasize swellings on the head region may come to exist as malignant lymphoma in cats.