title: Isolated fibrinoid vasculitis in renal angiomyolipoma.
abstract: Renal angiomyolipoma is a tumor composed of a mixture of thick-walled blood vessels, smooth muscle, and mature adipose tissue. It may present as a single unilateral lesion or as a multifocal uni- or bilateral neoplasm. The histologic spectrum of angiomyolipoma is wide but as far as we know intratumoral fibrinoid vasculitis has not been described in the tumor. This is the first report of isolated intratumoral fibrinoid vasculitis observed in two nodules of a unilateral multifocal renal angiomyolipoma. The vasculitis arose in a hypertensive 62-year-old woman who presented with a history of dull right flank and low back pain of 3 months' duration. There were no signs of generalized disease. Immunophenotyping of the vascular cellular infiltrate disclosed abundant T lymphocytes, significant numbers of histiocytes, and absence of B lymphocytes. The diagnosis of isolated intratumoral arteritis depends on the exclusion of systemic disease. It is important to distinguish cases like this one to avoid misdiagnosis and to prevent unnecessary treatment.
authors.affiliation: Anatomical Pathology Department, Marqués de Valdecilla University Hospital, Medical Faculty, University of Cantabria, Santander, Spain.
authors.forename: J F
authors.initials: JF
authors.lastname: Val-Bernal
authors.forename: M
authors.initials: M
authors.lastname: Hernando
mesh_terms: D018206:Angiolipoma / Q000150:complications / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000150:complications / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009392:Nephrectomy; D014057:Tomography, X-Ray Computed; D014657:Vasculitis / Q000150:complications / Q000473:pathology* / Q000601:surgery