title: Subcutaneous dirofilariasis: a masquerade of a palisaded granulomatous dermatitis.
abstract: Dirofilaria species are roundworms responsible for "heartworm" in canines. On occasion, humans are an accidental host, resulting in pulmonary (Dirofilaria immitis) or extrapulmonary (Dirofilaria repens) manifestations. Of the extrapulmonary sites of involvement, subcutaneous involvement is particularly common. We report a case of a 49-year-old female who presented with an erythematous nodule on her shin, which closely resembled necrobiosis lipoidica on histopathologic examination. On closer examination, there were foci of necrosis that harbored segments of the nematode, diagnostic of dirofiliarisis. We present this case to highlight the histopathologic similarities and differences between palisaded necrobiotic conditions and this potentially underrecognized entity.
authors.affiliation: Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
authors.forename: Kristen E
authors.initials: KE
authors.lastname: Muller
authors.affiliation: Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: Schwartzman
authors.affiliation: Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Seidel
mesh_terms: D000818:Animals; D003872:Dermatitis / Q000469:parasitology / Q000473:pathology; D060348:Dirofilaria repens; D004184:Dirofilariasis / Q000469:parasitology / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D012876:Skin Diseases, Parasitic / Q000469:parasitology / Q000473:pathology
keywords: dirofilariasis; granuloma annulare; granulomatous dermatitis; necrobiosis lipoidica; necrobiotic xanthogranuloma