This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ludatscher, R. M. Articles by Suntzeff, V. Search for Related Content PubMed PubMed Citation Articles by Ludatscher, R. M. Articles by Suntzeff, V.

An Electron Microscopic Study of Pulmonary Tumor Emboli from Transplantable Morris Hepatoma 5123¹

Departments of Anatomy and Pathology, Washington University School of Medicine, St. Louis, Missouri 63110

Lungs of 20 Buffalo rats with Morris hepatoma 5123 transplanted to the thigh were examined 5 to 12 weeks after transplantation. Metastases in the lungs as well as the thigh tumor were examined by light and electron microscopy. Pulmonary tumor emboli first were observed 6 weeks after transplantation. Metastases and tumor emboli were evident in lungs of all animals at 7 and 8 weeks. Naked tumor emboli without an endothelial covering were seen in intimate contact with the vascular lumen, and apparently sending out pseudopods in preparation for penetration between the endothelial vascular lining. Elsewhere they were seen immediately behind leukocytes that had already separated the vascular endothelial cells. It is postulated that embolic tumor cells penetrate vessels in the same manner as leukocytes. Some arrested endothelialized emboli were so altered as to appear nonviable, whereas others were well preserved. The cytologic details of the tumor, whether in emboli, metastases, or in the thigh transplant were reminiscent of normal liver.

¹ This work was supported by a grant (CA-05345) from the National Cancer Institute and a grant (GM-03784) from the Institute of General Medical Sciences, NIH, Bethesda, Maryland.

² Present address: Department of Anatomy, College of Physicians and Surgeons of Columbia University, 630 W. 168th Street, New York, New York 10032. Address reprint requests to this author.

Received 3/27/67. Accepted 6/15/67.