PULMONARY TUMOURS FOUND IN A BRITISH ABATTOIR SURVEY - PRIMARY CARCINOMAS IN CATTLE AND SECONDARY NEOPLASMS IN CATTLE SHEEP AND PIGS

The histological features of 25 primary carcinomas of the lung in cattle are described. The carcinomas were examined in the course of a survey of all tumours found in cattle, sheep and pigs in 100 abattoirs throughout Great Britain during one year. No primary lung cancers were encountered in sheep or pigs, though the series included one example of ovine pulmonary adenomatosis. The total numbers of slaughtered animals surveyed were 1.3 million cattle, 4.5 million sheep and 3.7 million pigs and 302 bovine, 107 ovine and 139 porcine tumours were received from the abattoirs. In cattle, the 25 lung cancers represented 83% of all neoplasms, occurring at a rate of 19 per million cattle slaughtered. The group of lung cancers included well-differentiated adenocarcinomas of acinar and papillary structure, squamous and oat-cell forms and several anaplastic carcinomas of polygonal-cell and pleomorphic types. In several specimens, there were transitions between 2 or more histological types within a single tumour. We have no evidence of any association between the anatomical distribution of the tumours within the lungs and their histological characteristics. In all but 1 case, metastases were noted. The usual sites of metastasis were the bronchomediastinal lymph nodes. Frequently other nodes in the thorax and abdomen were involved, as were the pleura, liver, kidneys and adrenals. The lung cancers were all from females, the majority over 5 years of age. The affected cattle originated from widely scattered rural areas, with no local clustering of cases. The secondary lung tumours in cattle, sheep and pigs are listed. In cattle, secondary deposits in the lung were more than twice as common as primary carcinomas and in the 3 species, lymphosarcoma was the most frequent secondary malignancy affecting the lungs. © 1968, The British Empire Cancer Campaign for Research. All rights reserved.