PUVA phototherapy-induced secondary amyloidosis in patients with mycosis fungoides: a rare adverse effect of phototherapy

Amyloidosis is a common disorder in adults. Secondary amyloidosis in patients with mycosis fungoides (MF) after photochemotherapy with 8-methoxypsoralen followed by ultraviolet A (PUVA) treatment has not been reported. Our aim is to describe the clinical and histological features of PUVA phototherapy-induced secondary amyloidosis. Materials and methods: Sixty-one patients with MF treated with PUVA phototherapy were analyzed clinically and pathologically and by staining with Congo red and crystal violet. Results: Of 61 patients, 5 met the study criteria. Secondary amyloidosis was detected in 5 patients treated with PUVA. The secondary amyloidosis appeared after a mean of 56 exposures (range: 30-81) and a mean cumulative PUVA radiation dose of 131.7 J/cm2 (range: 31-305.5). The mean follow-up duration from the date of occurrence of the secondary amyloidosis was 18.2 weeks (range: 10-30). Histologically, vacuolar interface changes, colloid bodies, and melanophages were seen in all 5 patients. There were 4 patients who had perivascular lymphocytic infiltration and 1 patient had lichenoid lymphocytic infiltration. Conclusion: It should be noted that secondary amyloidosis can be present in patients who have been treated with PUVA therapy and it can be a result of the apoptotic effect of PUVA on the basal keratinocytes.