Hypopigmented interface T‐cell dyscrasia: A form of cutaneous T‐cell dyscrasia distinct from hypopigmented mycosis fungoides

Abstract

Hypopigmentation in cutaneous T-cell lymphoproliferative disease should not always be equated with hypopigmented mycosis fungoides (MF). A form of hypopigmented pre-lymphomatous T-cell dyscrasia falling under the designation of the so-called hypopigmented interface variant of T-cell dyscrasia has recently been proposed. The aim of the present study was to establish hypopigmented interface T-cell dyscrasia as its own entity apart from other T-cell dyscrasias and MF using a patient case series. Twenty four cases of hypopigmented interface T-cell dyscrasia were identified in the dermatopathology database of Weill Medical College of Cornell University. There were 17 females and seven males (mean age, 36 years). In children and adolescents, the patients were most commonly of African American extraction. Truncal photo-protected areas manifesting as large solitary patches or multiple smaller macules were characteristic; disease progression to MF occurred in only one patient. The lesions responded to topical steroids and light therapy. The pathology was defined by a cell poor interface associated with degeneration of keratinocytes and melanocytes, and by lymphocytes whose nuclei showed low-grade cerebriform atypia, and which expressed a significant reduction in CD7 and CD62L expression. In 50% of the cases, the implicated cell type was of the CD8 subset. Clonality was not identified. Hypopigmented interface T-cell dyscrasia is a distinct entity separate from and rarely progressive to MF.

Two cases of CD8‐positive hypopigmented mycosis fungoides without TOX expression

“…e–h [data for CD45RA and CD45RO not shown]). Although other potential diagnoses, including vitiligo, pityriasis alba, nevus depigmentosus, tinea versicolor, and hypopigmented interface T cell dyscrasia, were considered irregular but well‐demarcated, hypopigmented patches with scaly erythematous patches and poikiloderma, together with the histological findings, led us to the diagnosis of HMF (T2N0M0B0, stage Ib). Both patients were treated with topical steroid and narrowband ultraviolet B therapy.…”

Unusual variants of mycosis fungoides

“…Some cases fit the described characteristics of lichenoid interface T-cell dyscrasia 26 , which may be best diagnosed retrospectively. Vitiligo may show more basement membrane thickening, complete loss of pigment and melanocytes, with absent lymphocytes, whereas CD8+ hypopigmented MF appears more “active” with hydropic degeneration and numerous lymphocytes.…”

Annular Lichenoid Dermatitis of Youth: Report of Six New Cases with Review of the Literature

“…Differential diagnosis included primarily morphea [14] and mycosis fungoides, mostly the hypopigmented variant [1,2,3,4,5,6,7,8,9,10,11,15,16,17,18,19,20,21], as well as the recently described variant named hypopigmented interface T cell dyscrasia [22]. Interestingly, hypopigmented mycosis fungoides has been reported in pediatric and young patients, especially in females with darker skin types [15,16,17,18,19,20,21].…”

“…Hypopigmented interface T cell dyscrasia should also be considered in the differential diagnosis of ALDY. It affects adults and shows cell-poor interface dermatitis featuring lymphocytes with low-grade cerebriform atypia and in 50% of the cases with a predominant CD8+ immunophenotype, but clonality was not identified [22]. Further, ALDY must clinically be distinguished from annular erythema, such as annular erythema of infancy and erythema annulare centrifugum, which, however, do not show histopathological lichenoid pattern.…”