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tvpjournal.com | September/October 2015 | TOday'S VeTerinary PracTice cOnSider ThiS caSe Peer reviewed 43 in this case, we did not attempt treatment, and the owners opted for euthanasia due to short survival time associated with current available treatments and poor quality of life of the patient. Palliative care would have consisted of pain control and treatment of the secondary infections. Amputation For those with digit metastasis, digital amputation as a treatment option has limited beneft; the median disease-free interval in cats with and without evidence of a lung mass at time of amputation was found to be 24 days, with median post amputation survival time being 104 days. 6 Tumor Removal an older retrospective study showed that surgical removal of primary lung tumors resulted in a PROFILE: PRImARy PuLmOnARy nEOPLAsIA Prevalence Primary pulmonary neoplasia is most common in older cats, with 11 to 12 years the mean age of presentation; 2 however, it is a rare occurrence in cats. Previous reports have suggested that it occurs in only 2.2 per 100,000 cats, but these numbers may be rising. This increase in occurrence may be due to increased age of the feline population or increased exposure to atmospheric pollutants. 5,9 Another possibility is that, with the use of more advanced technology and increased owner awareness about their cats' health, we are able to diagnose this condition more accurately. Classifcation There are several types of primary pulmonary carcinoma in cats, with the most common being bronchial adenocarcinoma (66%), followed by anaplastic carcinoma (12%), bronchoalveolar carcinoma (10%), and bronchial adenosquamous carcinoma (8%). 10 Both bronchial adenocarcinoma and bronchoalveolar carcinoma have been associated with metastasis to the digits, a condition also known as lung-digit syndrome. 5 Metastasis Primary pulmonary carcinomas have been shown to metastasize to the digits, ulna, fundus, lymph nodes, kidneys, spleen, limb muscles, and intestinal wall. 11-13 The pathogenesis of pulmonary carcinoma's predilection for digit metastasis is currently unknown, but it has been hypothesized that the digits are selectively affected due to the high digital blood fow in cats, which allows cats to maintain an appropriate core temperature. In patients with pulmonary carcinoma, this increased blood fow may predispose the digits to metastatic embolization and, thus, metastatic disease. 5 Metastasis is most commonly found in weight-bearing digits. 13 Presentation Cats with metastatic bronchial adenocarcinoma do not usually present for primary respiratory disease. Initial complaints are commonly lameness and pain associated with digital metastasis, or visual or neurologic defcits associated with metastasis to the fundus or brain. 4,12 Dyspnea, tachypnea, and cough can signify pulmonary involvement, while auscultation of the lungs may reveal increased bronchovesicular sounds or dullness of respiratory sounds. A history of anorexia and lethargy can also be an indication of neoplasia in older cats. Diagnostics • Thoracic radiographs reveal the presence of one or more pulmonary masses. • Pleural effusion is common in cats with advanced pulmonary neoplasia, and thoracocentesis may confirm the diagnosis when carcinoma cells are found in pleural fluid. • Fine needle aspiration (FNA) of pulmonary masses, using ultrasound or computed tomography guidance, is often diagnostic. • Bronchoalveolar lavage and transtracheal wash are additional diagnostic options. 14 • Biopsy of the affected digit(s) may allow histopathologic confirmation of the diagnosis. Samples collected by FNA or skin surface cytology are less invasive, and may help with the diagnosis; however, they may not provide sufficient information to confirm a diagnosis. • The gold standard for histopathologic evaluation is full digit amputation. 7