Mycosis fungoides involving an acrochordon: a case report.

We present the case of a 77-year-old male undergoing treatment for mycosis fungoides (MF) who presented for removal of an acrochordon on his mid back. Histopathologic examination of the acrochordon revealed a dense, band-like lymphocytic inflammatory infiltrate in the dermis with epidermotropism of single lymphocytes and small nests of lymphocytes into the lower epidermis. Immunohistochemical staining characterized the dermal and epidermal lymphocytic population as CD3-positive T lymphocytes with a predominance of CD4-positive over CD8-positive lymphocytes. These findings were consistent with the patient's known MF and molecular identification of a clonal T-cell receptor gene rearrangement further supported the diagnosis. Our unusual case reports MF involving an acrochordon and provides evidence to support the importance of submitting acrochordons for histopathologic examination.