Acral pseudolymphomatous angiokeratoma of children: immunohistochemical and clonal analyses of the infiltrating cells.
BACKGROUND
Acral pseudolymphomatous angiokeratoma of children (APACHE) is a disorder characterized clinically by red nodules and histopathologically by a massive subepidermal lymphohistiocytic infiltrate. Although it was initially thought to be a vascular nevus, it has never been regarded as a pseudolymphoma.


METHODS
We report a 7-year-old-girl with small red nodules on the dorsum of the right foot and a 73-year-old man with asymptomatic brown-red nodules on the lower extremities.


RESULTS
Histopathologic examination revealed a massive lymphohistiocytic infiltrate with plasma cells, some eosinophils, or a multinucleated giant cell immediately beneath the epidermis. Thick-walled vessels were observed in the infiltrate. These characteristics are identical to those of acral pseudolymphomatous angiokeratoma of children. The infiltrate was composed mainly of equal numbers of CD4+ or CD8+ T cells and equal numbers of B cells stained for kappa or lambda light chains. PCR amplification of rearranged immunoglobulin heavy chain genes or T-cell receptor gamma genes showed no evidence of clonality, suggesting that these infiltrates were polyclonal both for B and T cells.


CONCLUSIONS
Our data support the idea that this disorder represents a reactive process. The modified term 'papular angiolymphoid hyperplasia' would define this disorder more appropriately.
Hagari
Yoshitaka
Y
Department of Dermatology, Faculty of Medicine, Tottori University, Yonago, Japan. yohagari@grape.med.tottori-u.ac.jp
Hagari
Shinobu
S
Kambe
Naoto
N
Kawaguchi
Toshio
T
Nakamoto
Shu
S
Mihara
Motoyuki
M
D000368:Aged; D000794:Angiokeratoma / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D015703:Antigens, CD / Q000378:metabolism; D002648:Child; D002999:Clone Cells / Q000378:metabolism; D005260:Female; D005803:Genes, Immunoglobulin / Q000235:genetics; D019675:Genes, T-Cell Receptor gamma; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007147:Immunoglobulin Light Chains / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D016133:Polymerase Chain Reaction; D019310:Pseudolymphoma / Q000235:genetics* / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D012878:Skin Neoplasms / Q000235:genetics* / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
D015703:Antigens, CD; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains