1/3. Depigmented genital extramammary Paget's disease: a possible histogenetic link to Toker's clear cells and clear cell papulosis.BACKGROUND: The histogenesis of extramammary Paget's disease (EMPD) is still controversial. Benign pagetoid cells of the nipple first described by Toker and the similar clear cells found in white maculopapules of clear cell papulosis (CCP) have been proposed to be potential precursor cells giving rise to EMPD and primary intraepidermal Paget's disease in the nipple. The observation of a rare case of depigmented EMPD provided us with a chance to examine further the interesting Toker's clear cell/CCP hypothesis. methods: We performed pathologic studies, including Fontana-Masson stain and immunostaining for AE1/AE3 and S100P, on a new case of depigmented EMPD manifesting a 4 x 3 cm hypopigmented-depigmented patch on the root of the penis. RESULTS: The lesion showed extensive intraepithelial proliferation of atypical pagetoid cells with markedly reduced epidermal melaninization but nearly normal numbers of melanocytes. The tumor cells were strongly positive for AE1/AE3 by immunostaining. Some tumor cells displayed tadpole-like morphology resembling the pagetoid cells of CCP. Such morphology was not observed in two random examples of non-depigmented genital EMPD. CONCLUSIONS: The findings of tadpole-shaped pagetoid cells and depigmentation in the present case suggest that depigmented EMPD may be histogenetically related to CCP. Depigmented EMPD should be considered in the differential diagnosis of vitiligo, depigmented mycosis fungoides and lichen sclerosus located along the milk line.- - - - - - - - - - ranking = 1keywords = still (Clic here for more details about this article) |
2/3. Linear atrophoderma of Moulin: postulation of mosaicism for a predisposing gene.Hyperpigmented atrophoderma arranged in a pattern following the lines of Blaschko and appearing during childhood or adolescence on the trunk or the limbs is a characteristic feature of linear atrophoderma of Moulin. We review 15 published reports and describe 4 additional cases. Histopathologically, there is no clear sign of atrophy found in specimens examined by light microscopy. It might well be argued that a focal reduction of subcutaneous fatty tissue contributes to the obvious clinical atrophy. The cause and pathogenesis of the disorder remains unknown. It may reflect mosaicism caused by a postzygotic mutation that occurred at an early developmental stage, in analogy to many other diseases distributed along Blaschko's lines. Linear atrophoderma of Moulin may reflect the action of an autosomal lethal gene surviving by mosaicism. There are so far no reports of a familial occurrence that could favor a paradominant transmission of linear atrophoderma of Moulin. However, theoretically, the postzygotic mutation giving rise to an aberrant cell clone could still be nonlethal. In a heterozygous individual, a postzygotic mutational event might lead to loss of the corresponding wild-type allele at the atrophoderma locus. This would give rise to a homozygous cell clone, which becomes manifest along the lines of Blaschko later in life.- - - - - - - - - - ranking = 1keywords = still (Clic here for more details about this article) |
3/3. malignant atrophic papulosis.We describe a 34-year-old woman presenting with a 1-year history of asymptomatic, atrophic papules disseminated mainly on the trunk. The clinical features were characteristic of malignant atrophic papulosis, and the histopathologic features were confirmatory. The etiology of this rare condition, described for the first time in 1941, remains unknown. Also the pathogenesis is still controversial. A vascular disorder has been postulated by most authors, primary inflammatory or thrombotic vascular changes as well as primary endothelial proliferation being often mentioned in the literature. In the present case, the biopsy specimen of a recent efflorescence showed these three alterations all together, making it impossible to identify conclusively the primary event. thrombosis, being already noticed in such early lesions, is likely to be of pathogenic importance. Rheological therapy as described in the literature may therefore be the most appropriate. In the present case, the lesions came spontaneously to a standstill without drug therapy.- - - - - - - - - - ranking = 2keywords = still (Clic here for more details about this article) |