Abstract
A hard mass incidentally found in the right buttock of an elderly male A/J mouse was morphologically consistent with malignant fibrous histiocytoma; storiform-pleomorphic subtype. Diced pieces or suspensions of the tumor tissue were readily transplantable subcutaneously in the flank of mice of the strain. The tumor-bearing mice died mostly of rupture of the tumor into the thorax or abdomen within 4 weeks. Pulmonary and splenic metastasis were recognized only in a mouse which survived more than 10 weeks. A new cell-line was established from the original tumor without necessary cloning and was maintained in MEM (minimum essential medium) supplemented with 10%FCS for 6 months under 22 passages. Frozen stocks were then made, from which the recovery of the cells was successful. The cell growth, requiring about 20 hours for doubling of population, was a mixture of plump or stellate histiocytic cells and fibroblastic ones, both of which contained lipid droplets and retained phagocytic activity. The cell-line was designated as murine sarcoma Sendai (MuSS). Morphological versatility of the cultured cells suggested the origin of the neoplasm from multipotential, primitive mesenchymal cells.
