1/4. Phylloid hypomelanosis is closely related to mosaic trisomy 13.Phylloid hypomelanosis is a distinct type of pigmentary mosaicism characterized by congenital hypochromic macules resembling a floral ornament with various elements such as round or oval patches, macules resembling the asymmetrical leaves of a begonia, or oblong lesions. A review of cases with documentation of cytogenetic findings showed that aberrations involving chromosome 13 were present in 5 out of 6 patients. Examination of blood lymphocytes revealed a 46, XX/47 XX, 13 or 46, XX/47, XX, der (13) mosaic in three of these cases and a karyotype 46, XX, t(13;13) in the other two cases. cytogenetic analysis of skin fibroblasts showed chromosomal mosaicism in 4 of the 5 patients. In the remaining case, a chromosome 13 translocated on 13 was found in 100% of blood lymphocytes and skin fibroblasts, suggesting that mosaicism involving chromosome 13 may have developed in the melanocyte system. In conclusion, contrasting with hypomelanosis of Ito which is a cutaneous sign of many different states of mosaicism, phylloid hypomelanosis seems to originate preponderantly from a mosaic state involving chromosome 13. Future case reports may help to delineate further the significance of this relationship.- - - - - - - - - - ranking = 1keywords = hypochromic (Clic here for more details about this article) |
2/4. Unusual leukoderma after erythema multiforme: a case report.erythema multiforme is an inflammatory disorder of the skin that usually fades without sequelae. It is well known that after inflammatory events, hyper- or hypochromic spots can remain, especially in skin types III-VI, but achromia is very rare. We report a case of residual leukoderma after erythema multiforme.- - - - - - - - - - ranking = 1keywords = hypochromic (Clic here for more details about this article) |
3/4. Progressive and extensive hypomelanosis and extensive pityriasis alba: same disease, different names?We report the cases of five female patients with high skin phototype affected by relapsing, hypochromic, non-scaling macules occurring after the summer on the back and spreading over large areas of skin. Histological features disclosed decreased epidermal melanin. Psoralen plus ultraviolet A (PUVA) treatment proved to be beneficial, but new relapses were noted after stopping treatment. Clinical and histological features were consistent with the diagnosis of 'progressive and extensive hypomelanosis' described by Guillet in persons of mixed racial background. We discuss the differential diagnosis of the latter entity with respect to the other idiopathic acquired primitive hypomelanosis and hypothesize an overlapping with the so-called extensive pityriasis alba (EPA).- - - - - - - - - - ranking = 1keywords = hypochromic (Clic here for more details about this article) |
4/4. Hypomelanosis of Ito: a case report with clinical and ultrastructural data.Hypomelanosis of Ito (HI) is an uncommon skin disorder characterized by the presence of hypochromic areas associated with visceral abnormalities, the most common being neurological, muscular, skeletal and ocular. The authors describe a typical case of hypomelanosis of Ito in a 7-year-old child. The patient was obese, suffered from scoliosis, flat feet and had a bilateral genu valgus. No neurological, ophthalmological or dental malformations were noted. An electron microscopic study of a hypomelanotic area showed decreased functional activity in the melanocytes, which contained only a few rudimentary cytoplasmatic projections and poorly developed organelles. In addition, there was a reduction in the number of mature melanosomes.- - - - - - - - - - ranking = 1keywords = hypochromic (Clic here for more details about this article) |