Fibrofolliculoma with ancient/pseudosarcomatous features.
Fibrofolliculoma is a benign skin lesion that, when multiple, can be part of the Birt-Hogg-Dube syndrome. We report on a case of solitary fibrofolliculoma arisen on the nose of a 63-year-old woman, with peculiar histological and immunohistochemical features. The lesion was characterized by the presence of bizarre multinucleated perifollicular stromal cells, positive for factor XIIIa, in a background of CD34-positive cells, and by a peripheral population of CD34-positive spindle cells organized in fascicles haphazardly infiltrating the deep dermis, and surrounded by scattered factor XIIIa-positive dendrocytes. We consider the bizarre perifollicular cellular component as an 'ancient' feature of fibrofolliculoma, hypothesis corroborated by the co-expression of CD34 and factor XIIIa, whereas the peripheral spindle cell fascicles represent a pseudosarcomatous proliferation of CD34-positive cells, normally surrounding adnexal structures, stimulated by factor XIIIa-positive dendrocytes.
Cesinaro
Anna Maria
AM
Department of Pathology, University of Modena e Reggio Emilia, Modena, Italy. cesinaro.annamaria@policlinico.mo.it
Rusev
Borislav Chavdarov
BC
Kutzner
Heinz
H
D018952:Antigens, CD34 / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D026122:Factor XIIIa / Q000378:metabolism; D005260:Female; D006201:Hair Diseases / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D018859:Hair Follicle / Q000378:metabolism / Q000473:pathology*; D006222:Hamartoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D012535:Scalp; D016896:Treatment Outcome; D014746:Vimentin / Q000378:metabolism
D018952:Antigens, CD34; D015415:Biomarkers; D014746:Vimentin; D026122:Factor XIIIa