Significance of Distal Limb Lymphedema in Cats

Two cases of feline lymphangiosarcoma-a malignant neoplasm found rarely in cats-were documented in this report. The cats were young (case 1, aged 2 years; case 2, aged 6 years) and presented with persistent lymphedema of a distal limb with serosanguineous discharge of a digit that was unresponsive to antibiotic therapy. Case 1 initially presented with multiple petechial and ecchymotic hemorrhages; case 2 developed these lesions later. A cause of this defect could not be determined but seems to be common in all species affected by lymphangiosarcoma. Case 1 presented with severe, regenerative hemolytic anemia and case 2 had radiographically detected circumferential, cortical lysis in the affected foot. This is the first known report of immune-mediated hemolytic anemia and bone lesions in feline lymphangiosarcoma. Cytology was not found to be useful in these cases; both cats were diagnosed with histopathology of the affected tissue. Despite amputation and palliative treatment, the disease progressed rapidly in both cats and they were euthanized within weeks. Lymphangiosarcoma should be considered as a differential diagnosis in cats with persistent distal limb lymphedema accompanied by serosanguineous discharge, especially if local or distal ecchymoses are present.

COMMENTARY: This article provides interesting examples of "hoofbeats" that do turn out to be "zebras."  Lymphangiosarcoma is rare in cats but does occur. While it may not be the first thing on our differential list when we see a cat with a swollen distal limb, it is important to keep in mind-particularly when the limb is not responding to conventional treatment. Interestingly, cytology in these cases can actually be misleading and should not be relied upon for cats presenting with these signs.

Lymphangiosarcoma in two cats. Lenard ZM, Foster SF, Tebb AJ, et al. J Feline Med Surg 9:161-167, 2007.