Multiple osteolytic lesions and testicular involvement at first relapse of follicular lymphoma grade 1 in transformation.

A 62-year-old man was initially diagnosed with stage IA follicular lymphoma grade 1 of the left tonsil. Shortly after radiotherapy he rapidly developed multiple painful acroosteolytic lesions and testicular involvement. The histological examination revealed a transformed lymphoma in the testis (DLCL) and follicular lymphoma in the acroosteolytic lesions. The clonal identity of lymphoma cells within the primary biopsy as well as in the two sites at relapse was shown by PCR and nucleotide sequence analysis of the lymphoma clone specific B-cell receptor rearrangement. Chemotherapy with six cycles of CHOP followed by high dose chemotherapy and autologous blood stem cell transplantation led to a complete clinical remission with disappearance of all osteolytic lesions.