Pulmonary adenocarcinoma in two alpacas (Vicugna pacos)

Abstract

We describe here two cases of pulmonary neoplasia in alpacas: case 1 was a 19‐year‐old female huacaya alpaca that was submitted to investigate sudden death with possible previous weight loss. Gross and histological examination revealed changes consistent with primary lepidic‐type pulmonary adenocarcinoma (previously bronchioalveolar carcinoma) with metastases to the thorax and abdomen. Case 2 was a six‐year‐old male castrated Suri alpaca with a 3‐week history of weight loss and inappetance that was euthanased following a short period of recumbency and respiratory signs. Gross and histological features in this case were consistent with a diagnosis of metastatic adenocarcinoma affecting the lungs and lymph nodes. Masses from both alpacas were further characterised using immunohistochemistry for thyroid transcription factor 1 (TTF‐1), pan cytokeratin AE1/AE3 and vimentin. We show that histological subtype and TTF‐1 and AE1/AE3 immunoreactivity can be used to differentiate primary and metastatic pulmonary adenocarcinomas in the lungs of alpacas.