title: Unusual sclerosing haemangiomas and sclerosing haemangioma-like lesions, and the value of TTF-1 in making the diagnosis.
abstract: OBJECTIVE
  Sclerosing haemangiomas typically comprise a mixture of four architectural patterns (papillary, sclerotic, solid and haemorrhagic) and two cell types, eosinophilic cuboidal epithelial lining cells and sheets of rounded cells with either eosinophilic or clear cytoplasm. In most instances, recognition of these architectural and cytological features provides sufficient evidence for diagnosis. This study presents and discusses the histogenesis of four cases where difficulties in diagnosis were encountered, and reports the value of the antibody TTF-1 in making the diagnosis.
  
  
  RESULTS
  Four cases with focal areas reminiscent of sclerosing haemangioma were reviewed and immunostained with an antibody panel including antibodies to TTF-1 and surfactant apoprotein A. Of these, one case was classified as sclerosing haemangioma combined with typical carcinoid, in which there was a mediastinal lymph node metastasis solely comprising the solid component of sclerosing haemangioma. The second was classified as an alveolar adenoma with sclerosing haemangioma-like areas. In the remaining two cases, diagnosis was confounded by presentation with predominantly cystic masses, the largest 70 mm in diameter. Immunohistochemically, TTF-1 was of greater value than surfactant apoprotein, in particular in identifying the solid component of sclerosing haemangioma when this was solely present.
  
  
  CONCLUSIONS
  Sclerosing haemangiomas should be considered in the differential diagnosis of cystic pulmonary masses. They may also present histologically as combined tumours and metastasize to mediastinal nodes, indicating an, albeit low, malignant potential. TTF-1 is a valuable antibody in identifying the presence of a sclerosing haemangioma when typical features are absent.
authors.affiliation: Department of Histopathology, Royal Brompton Hospital, London, UK. a.nicholson@rbh.nthames.nhs.uk
authors.forename: A G
authors.initials: AG
authors.lastname: Nicholson
authors.forename: C
authors.initials: C
authors.lastname: Magkou
authors.forename: D
authors.initials: D
authors.lastname: Snead
authors.forename: H A
authors.initials: HA
authors.lastname: Vohra
authors.forename: M N
authors.initials: MN
authors.lastname: Sheppard
authors.forename: P
authors.initials: P
authors.lastname: Goldstraw
authors.forename: E
authors.initials: E
authors.lastname: Beddow
authors.forename: D M
authors.initials: DM
authors.lastname: Hansell
authors.forename: W D
authors.initials: WD
authors.lastname: Travis
authors.forename: B
authors.initials: B
authors.lastname: Corrin
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D003560:Cysts / Q000175:diagnosis / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006391:Hemangioma / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D007124:Immunoenzyme Techniques; D008171:Lung Diseases / Q000175:diagnosis / Q000378:metabolism; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000032:analysis; D013902:Radiography, Thoracic; D012598:Sclerosis / Q000378:metabolism / Q000473:pathology; D000074482:Thyroid Nuclear Factor 1; D014057:Tomography, X-Ray Computed; D014157:Transcription Factors / Q000032:analysis
chemical_list: D014408:Biomarkers, Tumor; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors