Hypopigmented, finely scaled macules and patches on the trunk and extremities of darker-skinned individuals have a wide clinical differential diagnosis in a dermatologic encounter. Most commonly, this type of rash can be attributed to a benign etiology such as tinea versicolor, idiopathic guttate hypomelanosis, pityriasis alba, and vitiligo. Entities categorized in the premalignant subset of dyspigmented skin disorders include pityriasis lichenoides, large plaque parapsoriasis, pigmented purpuric dermatosis, and the recently described hypopigmented interface T-cell dyscrasia.1-3
Clinical History
In this case of hypopigmented interface T-cell dyscrasia, a 19-year-old African American woman without a significant prior medical history had developed mildly pruritic hypopigmented patches with overlying fine scale on the abdomen, lower back, arms, and legs (Figures 1A-C). The course was waxing and waning over 5 years. She did not have features to suggest an atopic diathesis. Her medication history was unremarkable. Tinea versicolor, progressive macular hypomelanosis, and early vitiligo were among the clinical diagnostic considerations. A skin fungal culture was performed, which grew Trichosporon inkin, an organism known to cause piedra and tinea corporis.
However, despite treatment with topical ketoconazole shampoo and cream, the hypopigmentation and pruritus followed a persistent and somewhat progressive course on the trunk although the rash on her extremities resolved. A secondary diagnosis was made of eczema and she was started on triamcinolone cream for 2 weeks without effect.
Figures 1A-C. Clinical images of hypopigmented macules and patches on the back (A); left shoulder (B); and lower extremity (C).
Microscopic Findings
A biopsy of a hypopigmented patch on the right mid-back was subsequently performed, which revealed a superficial infiltrate of overall small- to medium-sized lymphocytes. Lymphocytes were present focally within the basal layer of the epidermis. There was concomitant basilar vacuolar change with incipient dyskeratosis. A few of the lymphocytes showed mild cerebriform atypia; however, the majority of lymphocytes were not atypical cytologically (Figures 2A and B).
Figures 2A-B. Hematoxylin and eosin (H&E) 20×. Focal epidermotropic T-cell colonization of the dermoepidermal
junction with emphasis on base of the rete ridges; mild vacuolar interface dermatitis is present (A). H&E 100×. Small
to medium-sized lymphocytes, some with angulated nuclei, colonize the dermoepidermal junction with exocytosis (B).
Phenotypic studies were conducted demonstrating positivity of the lymphocytes for the pan T-cell markers CD2, CD3, and CD5. There was a significant decrement in the staining for CD7 in the realm of 60% compared with the expression noted for CD2. The dominant intraepidermal lymphoid cell populace was of the CD8 subset (Figure 3).
Figure 3. Immunohistochemistry 20×. There is a clear CD8-dominant epidermotropic T-cell population, which would
be unusual in classical mycosis fungoides, where CD4 is predominant. Loss of CD7 is apparent compared to CD3.
Discussion
The term hypopigmented interface cutaneous T-cell dyscrasia was first coined in a seminal review from Guitart and Magro as a hypopigmented interface variant of T-cell dyscrasias, which was subsequently followed by a larger series published by Magro and colleagues in 2014.1,4 The distinction originated with the observation that younger patients diagnosed with hypopigmented mycosis fungoides actually had a benign nonprogressive clinical course unlike that of conventional mycosis fungoides.
The clinical features are distinctive with 2 primary presentations. In both types, there is a predilection for adolescents, often of African American descent. In the series published by Magro and collegaues4, patients can present with either large isolated hypopigmented patches in photoprotected areas or a more diffuse hypopigmented macular eruption resembling idiopathic guttate hypomelanosis and tinea versicolor.
In addition to the distinctive clinical features, reproducible light microscopic features include focal areas of relatively cell-poor lymphocyte mediated vacuolar interface dermatitis alternating with areas of passive colonization of lymphocytes.4 The lymphocytes are mildly atypical with a subset of cells showing a cerebriform outline. Phenotypically, the cells show findings typical of a T-cell dyscrasia including a significant reduction in the expression of CD7 and, less commonly, CD5. Interestingly, half of reported cases for hypopigmented T-cell dyscrasia exhibit a CD8+ dominant phenotype.4
While it is considered a premalignant entity, hypopigmented cutaneous T-cell dyscrasia is indolent in nature, with only 1 reported case of progression to frank hypopigmented mycosis fungoides.5 No treatment is generally required unless the lesions bother the patient, either symptomatically or cosmetically. The recognition of this entity is important because it avoids labeling young, otherwise healthy individuals with a diagnosis of a cutaneous lymphoma when the course is almost invariably benign and is truly considered a premalignant, not malignant, condition.6
Dr Magro is the director of dermatopathology at Weill Cornell Medicine in New York, NY.
Dr Wang is with Weill Cornell Medical College in New York, NY, and Memorial Sloan Kettering Cancer Center in New York.
Ms Thomas, PA-C, is with MD Dermatology of Maryland in Lexington Park.
Dr Saini is with MD Dermatology of Maryland in Lexington Park.
Disclosure: The authors report no relevant financial relationships.
References
1. Guitart J, Magro C. Cutaneous T-cell lymphoid dyscrasia: a unifying term for idiopathic chronic dermatoses with persistent T-cell clones. Arch Dermatol. 2007;143(7):921-932.
2. Lambert WC. Premycotic eruptions. Dermatol Clin. 1985;3(4):629-645.
3. Magro C, Crowson AN, Kovatich A, Burns F. Pityriasis lichenoides: a clonal T-cell lymphoproliferative disorder. Hum Pathol. 2002;33(8):788-795.
4. Magro C, Hagen JW, Crowson AN, et al. Hypopigmented interface T-cell dyscrasia: a form of cutaneous T-cell dyscrasia distinct from hypopigmented mycosis fungoides. J Dermatol. 2014;41(7):609-617.
5. Chuang GS, Wasserman DI, Byers HR, Demierre MF. Hypopigmented T-cell dyscrasia evolving to hypopigmented mycosis fungoides during etanercept therapy. J Am Acad Dermatol. 2008;59(5 suppl):S121-S122.
6. Burns MK, Ellis CN, Cooper KD. Mycosis fungoides-type cutaneous T-cell lymphoma arising before 30 years of age. Immunophenotypic, immunogenotypic and clinicopathologic analysis of nine cases. J Am Acad Dermatol. 1992;27(6 Pt 1):974-978.
Hypopigmented, finely scaled macules and patches on the trunk and extremities of darker-skinned individuals have a wide clinical differential diagnosis in a dermatologic encounter. Most commonly, this type of rash can be attributed to a benign etiology such as tinea versicolor, idiopathic guttate hypomelanosis, pityriasis alba, and vitiligo. Entities categorized in the premalignant subset of dyspigmented skin disorders include pityriasis lichenoides, large plaque parapsoriasis, pigmented purpuric dermatosis, and the recently described hypopigmented interface T-cell dyscrasia.1-3
Clinical History
In this case of hypopigmented interface T-cell dyscrasia, a 19-year-old African American woman without a significant prior medical history had developed mildly pruritic hypopigmented patches with overlying fine scale on the abdomen, lower back, arms, and legs (Figures 1A-C). The course was waxing and waning over 5 years. She did not have features to suggest an atopic diathesis. Her medication history was unremarkable. Tinea versicolor, progressive macular hypomelanosis, and early vitiligo were among the clinical diagnostic considerations. A skin fungal culture was performed, which grew Trichosporon inkin, an organism known to cause piedra and tinea corporis.
However, despite treatment with topical ketoconazole shampoo and cream, the hypopigmentation and pruritus followed a persistent and somewhat progressive course on the trunk although the rash on her extremities resolved. A secondary diagnosis was made of eczema and she was started on triamcinolone cream for 2 weeks without effect.
Figures 1A-C. Clinical images of hypopigmented macules and patches on the back (A); left shoulder (B); and lower extremity (C).
Microscopic Findings
A biopsy of a hypopigmented patch on the right mid-back was subsequently performed, which revealed a superficial infiltrate of overall small- to medium-sized lymphocytes. Lymphocytes were present focally within the basal layer of the epidermis. There was concomitant basilar vacuolar change with incipient dyskeratosis. A few of the lymphocytes showed mild cerebriform atypia; however, the majority of lymphocytes were not atypical cytologically (Figures 2A and B).
Figures 2A-B. Hematoxylin and eosin (H&E) 20×. Focal epidermotropic T-cell colonization of the dermoepidermal
junction with emphasis on base of the rete ridges; mild vacuolar interface dermatitis is present (A). H&E 100×. Small
to medium-sized lymphocytes, some with angulated nuclei, colonize the dermoepidermal junction with exocytosis (B).
Phenotypic studies were conducted demonstrating positivity of the lymphocytes for the pan T-cell markers CD2, CD3, and CD5. There was a significant decrement in the staining for CD7 in the realm of 60% compared with the expression noted for CD2. The dominant intraepidermal lymphoid cell populace was of the CD8 subset (Figure 3).
Figure 3. Immunohistochemistry 20×. There is a clear CD8-dominant epidermotropic T-cell population, which would
be unusual in classical mycosis fungoides, where CD4 is predominant. Loss of CD7 is apparent compared to CD3.
Discussion
The term hypopigmented interface cutaneous T-cell dyscrasia was first coined in a seminal review from Guitart and Magro as a hypopigmented interface variant of T-cell dyscrasias, which was subsequently followed by a larger series published by Magro and colleagues in 2014.1,4 The distinction originated with the observation that younger patients diagnosed with hypopigmented mycosis fungoides actually had a benign nonprogressive clinical course unlike that of conventional mycosis fungoides.
The clinical features are distinctive with 2 primary presentations. In both types, there is a predilection for adolescents, often of African American descent. In the series published by Magro and collegaues4, patients can present with either large isolated hypopigmented patches in photoprotected areas or a more diffuse hypopigmented macular eruption resembling idiopathic guttate hypomelanosis and tinea versicolor.
In addition to the distinctive clinical features, reproducible light microscopic features include focal areas of relatively cell-poor lymphocyte mediated vacuolar interface dermatitis alternating with areas of passive colonization of lymphocytes.4 The lymphocytes are mildly atypical with a subset of cells showing a cerebriform outline. Phenotypically, the cells show findings typical of a T-cell dyscrasia including a significant reduction in the expression of CD7 and, less commonly, CD5. Interestingly, half of reported cases for hypopigmented T-cell dyscrasia exhibit a CD8+ dominant phenotype.4
While it is considered a premalignant entity, hypopigmented cutaneous T-cell dyscrasia is indolent in nature, with only 1 reported case of progression to frank hypopigmented mycosis fungoides.5 No treatment is generally required unless the lesions bother the patient, either symptomatically or cosmetically. The recognition of this entity is important because it avoids labeling young, otherwise healthy individuals with a diagnosis of a cutaneous lymphoma when the course is almost invariably benign and is truly considered a premalignant, not malignant, condition.6
Dr Magro is the director of dermatopathology at Weill Cornell Medicine in New York, NY.
Dr Wang is with Weill Cornell Medical College in New York, NY, and Memorial Sloan Kettering Cancer Center in New York.
Ms Thomas, PA-C, is with MD Dermatology of Maryland in Lexington Park.
Dr Saini is with MD Dermatology of Maryland in Lexington Park.
Disclosure: The authors report no relevant financial relationships.
References
1. Guitart J, Magro C. Cutaneous T-cell lymphoid dyscrasia: a unifying term for idiopathic chronic dermatoses with persistent T-cell clones. Arch Dermatol. 2007;143(7):921-932.
2. Lambert WC. Premycotic eruptions. Dermatol Clin. 1985;3(4):629-645.
3. Magro C, Crowson AN, Kovatich A, Burns F. Pityriasis lichenoides: a clonal T-cell lymphoproliferative disorder. Hum Pathol. 2002;33(8):788-795.
4. Magro C, Hagen JW, Crowson AN, et al. Hypopigmented interface T-cell dyscrasia: a form of cutaneous T-cell dyscrasia distinct from hypopigmented mycosis fungoides. J Dermatol. 2014;41(7):609-617.
5. Chuang GS, Wasserman DI, Byers HR, Demierre MF. Hypopigmented T-cell dyscrasia evolving to hypopigmented mycosis fungoides during etanercept therapy. J Am Acad Dermatol. 2008;59(5 suppl):S121-S122.
6. Burns MK, Ellis CN, Cooper KD. Mycosis fungoides-type cutaneous T-cell lymphoma arising before 30 years of age. Immunophenotypic, immunogenotypic and clinicopathologic analysis of nine cases. J Am Acad Dermatol. 1992;27(6 Pt 1):974-978.
Hypopigmented, finely scaled macules and patches on the trunk and extremities of darker-skinned individuals have a wide clinical differential diagnosis in a dermatologic encounter. Most commonly, this type of rash can be attributed to a benign etiology such as tinea versicolor, idiopathic guttate hypomelanosis, pityriasis alba, and vitiligo. Entities categorized in the premalignant subset of dyspigmented skin disorders include pityriasis lichenoides, large plaque parapsoriasis, pigmented purpuric dermatosis, and the recently described hypopigmented interface T-cell dyscrasia.1-3
Clinical History
In this case of hypopigmented interface T-cell dyscrasia, a 19-year-old African American woman without a significant prior medical history had developed mildly pruritic hypopigmented patches with overlying fine scale on the abdomen, lower back, arms, and legs (Figures 1A-C). The course was waxing and waning over 5 years. She did not have features to suggest an atopic diathesis. Her medication history was unremarkable. Tinea versicolor, progressive macular hypomelanosis, and early vitiligo were among the clinical diagnostic considerations. A skin fungal culture was performed, which grew Trichosporon inkin, an organism known to cause piedra and tinea corporis.
However, despite treatment with topical ketoconazole shampoo and cream, the hypopigmentation and pruritus followed a persistent and somewhat progressive course on the trunk although the rash on her extremities resolved. A secondary diagnosis was made of eczema and she was started on triamcinolone cream for 2 weeks without effect.
Figures 1A-C. Clinical images of hypopigmented macules and patches on the back (A); left shoulder (B); and lower extremity (C).
Microscopic Findings
A biopsy of a hypopigmented patch on the right mid-back was subsequently performed, which revealed a superficial infiltrate of overall small- to medium-sized lymphocytes. Lymphocytes were present focally within the basal layer of the epidermis. There was concomitant basilar vacuolar change with incipient dyskeratosis. A few of the lymphocytes showed mild cerebriform atypia; however, the majority of lymphocytes were not atypical cytologically (Figures 2A and B).
Figures 2A-B. Hematoxylin and eosin (H&E) 20×. Focal epidermotropic T-cell colonization of the dermoepidermal
junction with emphasis on base of the rete ridges; mild vacuolar interface dermatitis is present (A). H&E 100×. Small
to medium-sized lymphocytes, some with angulated nuclei, colonize the dermoepidermal junction with exocytosis (B).
Phenotypic studies were conducted demonstrating positivity of the lymphocytes for the pan T-cell markers CD2, CD3, and CD5. There was a significant decrement in the staining for CD7 in the realm of 60% compared with the expression noted for CD2. The dominant intraepidermal lymphoid cell populace was of the CD8 subset (Figure 3).
Figure 3. Immunohistochemistry 20×. There is a clear CD8-dominant epidermotropic T-cell population, which would
be unusual in classical mycosis fungoides, where CD4 is predominant. Loss of CD7 is apparent compared to CD3.
Discussion
The term hypopigmented interface cutaneous T-cell dyscrasia was first coined in a seminal review from Guitart and Magro as a hypopigmented interface variant of T-cell dyscrasias, which was subsequently followed by a larger series published by Magro and colleagues in 2014.1,4 The distinction originated with the observation that younger patients diagnosed with hypopigmented mycosis fungoides actually had a benign nonprogressive clinical course unlike that of conventional mycosis fungoides.
The clinical features are distinctive with 2 primary presentations. In both types, there is a predilection for adolescents, often of African American descent. In the series published by Magro and collegaues4, patients can present with either large isolated hypopigmented patches in photoprotected areas or a more diffuse hypopigmented macular eruption resembling idiopathic guttate hypomelanosis and tinea versicolor.
In addition to the distinctive clinical features, reproducible light microscopic features include focal areas of relatively cell-poor lymphocyte mediated vacuolar interface dermatitis alternating with areas of passive colonization of lymphocytes.4 The lymphocytes are mildly atypical with a subset of cells showing a cerebriform outline. Phenotypically, the cells show findings typical of a T-cell dyscrasia including a significant reduction in the expression of CD7 and, less commonly, CD5. Interestingly, half of reported cases for hypopigmented T-cell dyscrasia exhibit a CD8+ dominant phenotype.4
While it is considered a premalignant entity, hypopigmented cutaneous T-cell dyscrasia is indolent in nature, with only 1 reported case of progression to frank hypopigmented mycosis fungoides.5 No treatment is generally required unless the lesions bother the patient, either symptomatically or cosmetically. The recognition of this entity is important because it avoids labeling young, otherwise healthy individuals with a diagnosis of a cutaneous lymphoma when the course is almost invariably benign and is truly considered a premalignant, not malignant, condition.6
Dr Magro is the director of dermatopathology at Weill Cornell Medicine in New York, NY.
Dr Wang is with Weill Cornell Medical College in New York, NY, and Memorial Sloan Kettering Cancer Center in New York.
Ms Thomas, PA-C, is with MD Dermatology of Maryland in Lexington Park.
Dr Saini is with MD Dermatology of Maryland in Lexington Park.
Disclosure: The authors report no relevant financial relationships.
References
1. Guitart J, Magro C. Cutaneous T-cell lymphoid dyscrasia: a unifying term for idiopathic chronic dermatoses with persistent T-cell clones. Arch Dermatol. 2007;143(7):921-932.
2. Lambert WC. Premycotic eruptions. Dermatol Clin. 1985;3(4):629-645.
3. Magro C, Crowson AN, Kovatich A, Burns F. Pityriasis lichenoides: a clonal T-cell lymphoproliferative disorder. Hum Pathol. 2002;33(8):788-795.
4. Magro C, Hagen JW, Crowson AN, et al. Hypopigmented interface T-cell dyscrasia: a form of cutaneous T-cell dyscrasia distinct from hypopigmented mycosis fungoides. J Dermatol. 2014;41(7):609-617.
5. Chuang GS, Wasserman DI, Byers HR, Demierre MF. Hypopigmented T-cell dyscrasia evolving to hypopigmented mycosis fungoides during etanercept therapy. J Am Acad Dermatol. 2008;59(5 suppl):S121-S122.
6. Burns MK, Ellis CN, Cooper KD. Mycosis fungoides-type cutaneous T-cell lymphoma arising before 30 years of age. Immunophenotypic, immunogenotypic and clinicopathologic analysis of nine cases. J Am Acad Dermatol. 1992;27(6 Pt 1):974-978.
