title: Subungual myxoid pleomorphic fibroma.
abstract: The authors report an example of pleomorphic fibroma in a unique site: the subungual space of the thumb. A 54-year-old man presented with paronychia and markedly thickened hyperkeratotic nail. The nail plate was removed, and an exophytic, red, friable, granulation tissue-like lesion was revealed subungually. The lesion was diagnosed clinically as pyogenic granuloma. Excisional biopsy was performed. Histologically, the lesion showed a hypocellular fibroma with myxoid areas and dilated blood vessels. Interspersed with ordinary appearing fibroblasts, there were bizarre, atypical fibroblasts with hyperchromatic and large, pleomorphic nuclei and multinucleated floret-like giant cells. These atypical cells showed strong immunoreactivity with antibodies against CD34 and vimentin. Occasional positivity was noted with factor XIIIa and alpha-1-antichymotrypsin, whereas no reactivity occurred with alpha-1-antitrypsin, actin, or S-100 protein. The entity of pleomorphic fibroma has been reported in many body sites; however, this is the first case to be reported in the subungual space.
authors.affiliation: Department of Dermatology, Allegheny University of the Health Sciences (Hahnemann Campus), Philadelphia, Pennsylvania, USA.
authors.forename: A
authors.initials: A
authors.lastname: Hassanein
authors.forename: G
authors.initials: G
authors.lastname: Telang
authors.forename: E
authors.initials: E
authors.lastname: Benedetto
authors.forename: R
authors.initials: R
authors.lastname: Spielvogel
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis; D005350:Fibroma / Q000737:chemistry / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009262:Nails / Q000473:pathology*; D012878:Skin Neoplasms / Q000737:chemistry / Q000473:pathology*; D013933:Thumb; D014746:Vimentin / Q000032:analysis
chemical_list: D018952:Antigens, CD34; D014746:Vimentin