ISSN:0193-1091    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Mycosis fungoides (MF) can present with purpuric lesions, and rare patients who seemed to have persistent pigmented purpuric dermatitis (PPPD) have developed MF. We recently encountered two patients referred to our cutaneous lymphoma clinic who had PPPD rather than MF and two others who appeared to have both conditions, leading us to explore the histologic similarities of these diseases. We examined specimens from 56 patients with PPPD to determine the frequency of MF-like histologic configurations, namely, the psoriasiform lichenoid, psoriasiform spongiotic lichenoid, and atrophic lichenoid patterns. We also noted the degree of spongiosis, epidermotropism, papillary dermal fibrosis, lymphocytic atypia, and epidermal hyperplasia, the number of extravasated erythrocytes and siderophages, and the distribution of lymphocytic infiltrate within the epidermis. In 29 of 56 patients, there were patterns typically seen in MF. PPPD can feature lymphocytes aligned along the epidermal side of the dermoepidermal junction, with few necrotic keratinocytes, as can MF. Papillary dermal edema occurred frequently in PPPD but not in MF, while lymphocytes in MF but not PPPD had markedly atypical nuclei and had ascended into the upper spinous layer. Given these similarities, we tested for clonality of the T-cell population using a polymerase chain reaction assay for γ-chain rearrangements. Clonal populations were present in three of three and one of two specimens from patients with both PPPD and MF, but also in 8 of 12 specimens typical of lichenoid patterns of PPPD. These findings raise the possibility that the lichenoid variants of PPPD are biologically related to MF.

ISSN:0193-1091    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Papular urticaria is the result of hypersensitivity (idreaction) to bites from certain insects such as mosquitoes gnats, fleas, mites, and bedbugs. Papular urticaria is common in childhood and is characterized by symmetrically distributed pruritic papules and papulovesicles. Scratching causes erosions and ulcerations. Pyoderma is common. Lesions occur in crops. The histopathologic features of papular urticaria are inadequately documented. In a prospective study we recorded the histopathologic features of 30 patients (female, 18; male, 12) with papular urticaria. Their ages ranged from 6-343 months (median = 21 months, mean = 37.73 months). Features that presented in more than 50% of cases included mild acanthosis, mild spongiosis, exocytosis of lymphocytes, mild subepidermal edema, extravasation of erythrocytes, a superficial and deep mixed inflammatory cell infiltrate of moderate density, and interstitial eosinophils. We recognized lymphocytic (n = 4), eosinophilic (n = 9), neutrophilic (n = 7), and mixed (n = 9) subtypes. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded sections from 10 cases and revealed abundant T-lymphocytes (CD45RO, CD3) and macrophages (CD68) in all cases. B-lymphocytes (CD20) and dendritic antigen-presenting cells (S100) were absent. Direct immunofluorescence staining was conducted on cryostat-prepared sections from 26 specimens. Deposition of IgA, IgG, IgM, C3, and fibrin could not be demonstrated. The histopathologic differential diagnosis of papular urticaria includes other spongiotic dermatitides, pityriasis lichenoides et varioliformis acuta, the pruritic papular eruption of human immunodeficiency virus disease, and papulonecrotic tuberculid. Papular urticaria with marked spongiosis and a dense inflammatory cell infiltrate cannot be reliably distinguished from arthropod bites on clinical and histopathologic grounds. The present study provides morphologic and immunohistochemical evidence that a type I hypersensitivity reaction plays a central role in the pathogenesis of papular urticaria. The putative antigen remains undetermined.

ISSN:0193-1091    

出版商:OVID    

年代:1997

数据来源: OVID

摘要:

Pachyonychia congenita (PC) is a rare genodermatosis with characteristic nail abnormalities and occasional palmoplantar keratoderma and leukokeratosis oris; alopecia may occur (10% of patients). This report is the first microscopic description of a patient with PC-associated alopecia. Transverse section histologic features include diminished follicular density with preservation of follicular units, prominent miniaturization of follicles, dyskeratosis of outer root sheath keratinocytes, and moderate parakeratotic and orthokeratotic follicular hyperkeratosis. These microscopic features may be seen individually in other nonscarring alopecias, but the combination may be unique to PC-associated alopecia. Differential diagnoses include alopecia areata, androgenetic alopecia and traction alopecia/trichotillomania.

ISSN:0193-1091    

出版商:OVID    

年代:1997

数据来源: OVID