The time interval between tumor inoculation and metastatic spread to the lymph nodes.

Little is known about the time when a malig nant growth may first release tumor emboli into the lymphatic system. The problem can be inves tigated by employing the technic of anterior cham ber inoculation, since the primary tumor may be readily destroyed by eye enucleation or x-radiation. Mouse tumor C-1300 appeared suitable for this purpose, since it metastasizes to the cervical lymph nodes of all inoculated animals of a suscep tible strain. Because the métastases remain con fined to the cervical nodes, it is unlikely that spread has occurred by other than lymphatic channels. It was the purpose of this study to de termine when the tumor first metastasizes from the eye to the regional lymph nodes. Clearly, the results apply only to the tumor and host strain studied. MATERIALS AND METHODS Mouse tumor C-1300 (neuroblastoma) was injected into the anterior chamber of ABC mice of either sex weighing 15-22 gm. The technic of transplantation has been described previously (1). Four methods were used to detect the presence of métastases in the cervical nodes. 1. Eye enucleation.—At definite intervals after transplantation, the affected eye was enucleated by lifting and incising the conjunctiva and by severing the eye from its lateral and posterior at tachments without undue pressure on the eye to prevent spillage of tumor cells into the periocular structures. The animals were observed over a peri od of 60 days for the development of cervical lymph node enlargement. 2. X-ray therapy.—3,000 r/air, (100 kvP, 10 ma., 1.0 mm. Al filter, HVL 2.0 mm. Al, FSD 21 cm.) were administered as a single treatment through a 0.8-cm. field surrounding the orbit on the 4th, 5th, 6th, 8th, 10th, 12th, and 15th day, respectively. Lymph node enlargement was re corded as in above paragraph, method no. 1. 3. Lymph node transfer.—At definite intervals