CHROMOSOMES IN BURKITT LYMPHOMAS .I. SERIAL STUDIES IN A CASE WITH BILATERAL TUMORS SHOWING DIFFERENT CHROMOSOMAL STEMLINES

The chromosomes of a Burkitt lymphoma case were followed through a period of three months, including stages before treatment and during treatment and progression. The patient had bilateral facial tumors with metastases to lymph nodes on either side of the neck. The chromosomal stemlines were different on the left and the right side. Both were diploid, the left side representing the normal karyotype, the right side exhibiting a number of marker chromosomes. This difference characterized both the facial tumors and the neck metastases. During early stages of the right‐side tumor, the marker chromosomes M2 and MC predominated. Both were derived from C group chromosomes and had a constriction on their longer arm, separating a distal segment from the rest of the chromosome. M2 had the appearance of a small No. 2 chromosome, MC that of a large C chromosome. Later on, M2 was replaced by M1 through translocation of the distal segment to a No. 1 chromosome. Two other marker chromosomes MB and MD resembled B and D chromosomes, respectively, with elongated long arms. At terminal stages of the disease, when chemotherapeutic treatments had been administered repeatedly, highly disturbed chromosome conditions prevailed with numerous signs of chromosome breakage and errors of spiralization. Also a cultured cell line established at an early stage from the right‐side tumor showed a high incidence of similar aberrations. All the marker chromosomes, except, M1, were recovered in the culture. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company