Department of Medicine B, Hasharon Hospital, Golda Medical Center, Petah-Tiqva, Israel.
Transverse grooves of the nails, designated as Beau's lines, were observed in a patient with malignant lymphoma given chemotherapy. Beau's lines disappeared in the treatment-free intervals. This observation supports the concept that these lines are the result of the suppressed growth of the nail matrix caused by antimitotic drugs.