Summary

A 14-year-old girl presented with a circular erythematous patch over the left buttock for approximately 10 years, with ongoing ulceration and papules developing over the last 4 years. Punch biopsies were taken within and above the patch for diagnosis. Both revealed marked inflammatory infiltrates with atypical, irregular lymphocytes and increased mitosis. Immunostaining revealed CD8 positivity and a pan T helper cell phenotype. T cell receptor gene rearrangement analysis showed T cell clonality in both biopsies. These findings were consistent with mycosisfungoides and associated lymphomatoid papulosis. Both are rare conditions but have been associated in 5%–20% of cases.⇓ A definitive association has not yet been established; however, T cell monoclonality shows 50%–60% share a common origin. Management options are extensive with no one treatment showing superiority.⇓ Our patient received low-dose radiotherapy with good outcomes, but subsequently required further radiotherapy.