Feline lymphoma 2. Specific disease presentations

THIS article, the second of two on feline lymphoma, discusses how the disease can present to the veterinarian. Lymphoma is a differential diagnosis for a variety of clinical presentations in cats and can occur in, or spread to, any anatomical site that contains lymphoid tissue. A regionally localised disease must be assumed to have a systemic component unless proved otherwise. Thus, ascribing a disease to a particular anatomical form (ie, mediastinal, alimentary or multicentric) can be difficult and may have led to inaccuracies in reporting of the disease in the literature. In addition to these commonly recognised forms, cutaneous, ocular, central nervous system, tracheal, renal, nasal and pulmonary forms are also recognised. These various anatomical presentations of feline lymphoma may come to be regarded as specific disease entities in their own right as more is learnt about the pathogenesis and biology of feline lymphoid neoplasias, but are currently best considered as manifestations of a disease continuum. Rather than struggling to ascribe an individual case to a particular anatomical form, the clinician should be aware that the main aim of staging is simply to document all areas of involvement. Initial clinical investigations will pertain to the organ system recognised in the presentation of disease, but full staging is always required and should include diagnostic investigation of the whole patient wherever possible. This was discussed further in Part 1, published in the last issue, which reviewed the principles of diagnosis and management in feline lymphoma cases ( In Practice , October 2006, volume 28, pp 516–524).