title: Nodular erythema elevatum diutinum mimicking cutaneous neoplasms.
abstract: OBJECTIVE
  We describe the cutaneous pseudoneoplastic lesions in two patients with nodular erythema elevatum diutinum, a rare chronic disorder in which polymorph nuclear fragmentation (leukocytoclasis) is present within dermal nodules showing spindle cells and fibrosis. In both cases diagnostic difficulty was encountered clinically and pathologically and various benign and malignant neoplasms were considered in the differential diagnosis.
  
  
  RESULTS
  Immunohistochemically the spindle cells were negative for CAM5.2, AE1/3, S100 protein and desmin (D33). They were positive for vimentin and focally positive for CD34 and alpha-smooth muscle actin. Some of the spindle cells were positive for Mac 387 and KP1(CD68). By electron microscopy, the lesions were shown to consist of fibroblasts/myofibroblasts and fusiform macrophages.
  
  
  CONCLUSIONS
  Increased awareness of the features described will help to avoid misdiagnosis as a neoplastic process.
authors.affiliation: Department of Histopathology, Christie Hospital NHS Trust, UK.
authors.forename: J H
authors.initials: JH
authors.lastname: Shanks
authors.forename: S S
authors.initials: SS
authors.lastname: Banerjee
authors.forename: P W
authors.initials: PW
authors.lastname: Bishop
authors.forename: J M
authors.initials: JM
authors.lastname: Pearson
authors.forename: B P
authors.initials: BP
authors.lastname: Eyden
mesh_terms: D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D004891:Erythema Induratum / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D012871:Skin Diseases / Q000473:pathology*; D012878:Skin Neoplasms / Q000473:pathology* / Q000648:ultrastructure