title: A clinical and histologic mycosis fungoides simulant occurring as a T-cell infiltrate coexisting with B-cell leukemia cutis.
abstract: One year after the onset of chronic lymphocytic leukemia, an elderly man had scaly cutaneous plaques on the thighs that clinically and histologically resembled the mycosis fungoides type of cutaneous T-cell lymphoma. Two years later the patient had indurated, red dermal nodules on the face that clinically and histologically were characteristic of cutaneous chronic lymphocytic leukemia. Immunophenotyping results from a facial nodule confirmed the presence of a B-cell infiltrate (CD20+). Immunophenotyping of a lesion on the right thigh showed that half the cells were composed of a CD2+, CD45RO+ (UCHL-1+) upper dermal and focally epidermotropic population of T cells consistent with mycosis fungoides; however, these T cells coexisted with an equal number of CD20+ B cells arranged in distinct clusters. DNA from the thigh lesion exhibited a B-cell immunoglobulin gene rearrangement, but the T-cell receptor gene rearrangements were germline. In this case, the evidence favors a mycosis fungoides simulant occurring as a reactive T-cell infiltrate to an underlying B-cell chronic lymphocytic leukemia.
authors.affiliation: Cutaneous Lymphoma Program, University of Michigan Comprehensive Cancer Center, Ann Arbor, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Metzman
authors.forename: S R
authors.initials: SR
authors.lastname: Stevens
authors.forename: C E
authors.initials: CE
authors.lastname: Griffiths
authors.forename: C W
authors.initials: CW
authors.lastname: Ross
authors.forename: J M
authors.initials: JM
authors.lastname: Barnett
authors.forename: K D
authors.initials: KD
authors.lastname: Cooper
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D015321:Gene Rearrangement; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications / Q000235:genetics / Q000473:pathology*; D008297:Male; D009182:Mycosis Fungoides / Q000209:etiology* / Q000235:genetics / Q000473:pathology; D012878:Skin Neoplasms / Q000209:etiology* / Q000235:genetics / Q000473:pathology; D013601:T-Lymphocytes