Thymocyte selection-associated high-mobility group box as a potential diagnostic marker differentiating hypopigmented mycosis fungoides from early vitiligo: A pilot study.

BACKGROUND: Hypopigmented mycosis fungoides is a rare variant of mycosis fungoides that may mimic many benign inflammatory hypopigmented dermatoses, and as yet there is no identified marker to differentiate between them. AIM: The aim of this study was to study the expression of thymocyte selection-associated high-mobility group box (TOX) in hypopigmented mycosis fungoides and one of its inflammatory mimickers (early active vitiligo) to assess its potential as a differentiating diagnostic marker. METHODS: A case-control study was done using immunohistochemical analysis of TOX expression in 15 patients with hypopigmented mycosis fungoides and 15 patients with early active vitiligo. Immunohistochemical analysis was done via a semi-quantitative method and an image analysis method. RESULTS: Hypopigmented mycosis fungoides showed a statistically significant higher expression of TOX than early active vitiligo. The expression of TOX was positive in a majority of hypopigmented mycosis fungoides cases (14 cases, 93.3%), while only one case (6.7%) of vitiligo was weakly positive. TOX also displayed 93.3% sensitivity and specificity, with a cut-off value of 1.5. LIMITATIONS: This was a pilot study testing hypopigmented mycosis fungoides against only a single benign inflammatory mimicker (early vitiligo). Other benign mimickers were not included. CONCLUSION: Our findings showed that TOX expression can differentiate hypopigmented mycosis fungoides from early active vitiligo which is one of its benign inflammatory mimickers, with a high degree of sensitivity and specificity.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment.

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Presentations, Signs of Activity, and Differential Diagnosis of Vitiligo.

Vitiligo has a variety of presentations, including focal, acrofacial, segmental, and generalized forms. Thorough knowledge of these presentations is important to make the correct diagnosis. Signs of activity are important to recognize so that treatment is optimized. Clinical findings of confettilike depigmentation, trichrome and inflammatory vitiligo, and the Koebner phenomenon should alert the clinician that a patient's disease is likely to worsen. These patients may require systemic treatment to stabilize their disease. Many other skin disorders present with hypopigmentation or depigmentation and must be distinguished to determine the right diagnosis, advise the patient on prognosis, and prescribe the correct treatment.

[Linear tuberculoid leprosy along the lines of Blaschko: a very rare presentation]. / Lèpre tuberculoïde de disposition linéaire blaschkoïde: une présentation exceptionnelle.

BACKGROUND: Leprosy continues to be present in certain regions throughout the world, and the dermatologist plays a central role in its diagnosis. Herein we report a case of tuberculoid leprosy that is atypical in terms of its linear presentation which appears to follow the lines of Blaschko. PATIENTS AND METHODS: A patient from Mayotte was referred to the neurological department for suspected tuberculoid leprosy. He was presenting a deficiency of the ulnar nerve together with neuronal hypertrophy and cutaneous involvement. Dermatological examination revealed linear hypo-aesthetic hypopigmented lesions on the arm and forearm. The atypical clinical presentation also suggested to us pigmented mosaicism or post-inflammatory pigmentation. The biopsy showed granulomatous epithelial dermatitis with perinervous involvement. Imaging examinations confirmed the presence of neuronal hypertrophy. A diagnosis of linear tuberculoid leprosy was made. DISCUSSION: This case illustrates the need to bear in mind a diagnosis of leprosy in the event of hypopigmented lesions, even where they are linear and of Blaschkoid appearance. Several potential hypotheses may account for this particular topographical pattern.

[Etiology of acquired hypochromic patches in dermatological area in Mali]. / Etiologies Des Hypochromies Acquises En Milieu Dermatologique.

INTRODUCTION: In dark skin patients, hypopigmentation is the most disfiguring condition. Very few studies on hypochromic disorders have been conducted in specialized health centers. The present study is aimed to describe the etiologies of hypochromic patches in dermatological area, in Bamako. METHODS: We carried out a cross sectional study in the Dermatology Clinic of the "Centre National d'Appui à la lutte contre la Maladie (CNAM, Ex Institut Marchoux)". All acquired hypochromic patches (HP) were selected. HP was defined as a "skin patch lighter in pigmentation than normal surrounding skin with a diameter of at least 1 cm". The diagnosis was mainly based on clinical findings. RESULTS: The prevalence of HP was 3.42% and the main causes were seborrheic dermatitis (23.3%), pytiriasis alba (20.15%), vitiligo (18.9%), pityriasis versicolore (18.5%) and leprosy (12.6%). CONCLUSION: There are many causes of HP including leprosy, a disease though rare to date, but still prevalent in dermatological area.

Hypopigmented macules: leprosy, atopy or pityriasis versicolor?

Lepromatous leprosy (LL) represents the highest infective and multibacillary form of leprosy. Clinical manifestations are consequent to the haematogenous spread of bacilli and include macules, plaques and nodules in a symmetric distribution or a diffuse infiltration of the skin. LL may mimic many different inflammatory and neoplastic skin diseases and in a small percentage of patients, skin manifestation may be atypical. This article reports the case of a South American child with LL presenting with symmetrically distributed hypopigmented macules previously misdiagnosed as pytiriasis alba, atopic dermatitis and pityriasis versicolor. Atopy and pityriasis versicolor are common skin conditions that can be also observed in leprosy patients and that can masquerade the diagnosis of LL, especially if occurring in dark skin. Dermatologists in Europe should be aware of this unusual form of presentation of leprosy and must take in mind Hansen disease in the differential diagnosis in patients coming from endemic areas.

Neurofibromatosis I with unusual hypopigmentation masquerading as leprosy.

A case of Neurofibromatosis I (NFI) occurring in association with symmetrical peripheral nerve enlargement and multiple hypopigmented macules strikingly limited to the neurofibromas, with normal to minimally reduced sensations, evoking a strong clinical suspicion of co-existent lepromatous leprosy, is being reported. Leprosy was ruled out by microbiological, histopathological and electrophysiological studies. The case is interesting in view of the hypopigmented macules overlying the neurofibromas, which is an unreported feature of NFI.

A novel, antigen-presenting function of melanocytes and its possible relationship to hypopigmentary disorders.

It is now well established that cultured human melanocytes are capable of expressing immunologically important cell surface molecules and that they can produce cytokines. Not all cells with the ability to express MHC class II molecules are capable of effective Ag presentation. However, the dendritic nature of melanocytes, their strategic position within the skin, and their phagocytic capacity seem to suggest a role for these cells in processing and presenting Ag. This study demonstrates that cultured normal human skin melanocytes can present peptide Ag, and process and present the mycobacterial HSP65 kDa protein and whole Mycobacterium leprae sonicate to CD4+ cytotoxic proliferative T cell clones in an Ag-specific and HLA-class II-restricted manner. T cell stimulation was dependent on costimulatory signals, i.e., LFA-3/CD2 and LFA-1/ICAM-1. Besides eliciting a T cell proliferative response, our studies further demonstrate that melanocytes can function as target cells for T cell-mediated cytotoxicity. The described Ag-processing and -presenting functions of melanocytes, taken together with in vivo behavior of melanocytes in hypopigmentation, provide new clues for the etiopathogenesis of melanin pigmentary disorders.