Squamous cell carcinoma appearing in X-ray-treated mycosis fungoides.

Two patients with mycosis fungoides developed a squamous cell carcinoma of the skin on the neck. Upon verification by routine biopsy testing of material taken from a suppurating infiltrate of the neck, both patients were treated intermittently with X-rays. Both had developed the squamous cell carcinoma on a sun-exposed area. Patient 1 had been treated with Grenz-ray irradiation totalling 10 kilovolt (kV) 4400 rad. and Dermopan step IV (50 kV) 5200 rad.; while patient 2 recieved altogether: Grenz-rays 4600 rad., Dermopan step IV 400 rad., and soft X-rays (150 kV) 800 r. The latency period was, respectively, 3 and 10 years.