title: Diagnostic challenges of oral and cutaneous Kaposi's sarcoma in resource-constrained settings.
abstract: OBJECTIVE
  Kaposi's sarcoma (KS), caused by HHV-8, is the most frequent HIV-associated malignancy worldwide and remains a major scourge in Sub-Saharan Africa. KS is also endemic in much of Africa. There is a risk of misdiagnosis based solely on clinical appearance and haematoxylin and eosin (H&E) staining, especially with other reactive and neoplastic vascular proliferations which occur in the mouth. This study examined oral and cutaneous biopsies from clinically diagnosed lesions of KS in Kenya, using histopathology supplemented with immunohistochemistry (IHC) and polymerase chain reaction (PCR) for HHV-8 as confirmation of diagnosis.
  
  
  METHODS
  Biopsies of 49 lesions (28 oral, 21 cutaneous) previously diagnosed as 'KS' were re-examined by H&E staining and IHC targeting HHV-8 LANA-1. Positive controls were sections from embedded BCBL-1 cell lines. Negative controls were from three different HHV-8-negative biopsies. Confirmation of HHV-8 immunohistochemistry was sought by PCR and by determining the HHV-8 ORFK1 subtype.
  
  
  RESULTS
  Whilst most cases were confirmed, 12 oral and 4 cutaneous lesions displayed clinical and histological features of KS but were negative to HHV-8 IHC. These oral lesions were re-diagnosed as pyogenic granulomata (n = 6), deep mycosis (n = 1), inflamed mucosa (n = 2) or 'uncertain but not KS' (n = 3). Whilst PCR is usually helpful in differentiating HHV-8 disease, all samples were HHV-8 PCR positive, with identical sequences, suggesting cross-contamination of samples in the original pathology laboratories.
  
  
  CONCLUSIONS
  HHV-8 IHC is essential for the correct diagnosis of KS, but due to the high level of contamination in resource-poor settings, PCR is inadvisable.
authors.affiliation: School of Dentistry and Oral Health, Griffith University, Gold Coast, Qld, Australia.|Molecular Basis of Disease Research Program, Menzies Health Institute Queensland, Griffith University, Gold Coast, Qld, Australia.|Population & Social Health Research Program (Population Oral Health), Menzies Health Institute Queensland, Griffith University, Gold Coast, Qld, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Speicher
authors.affiliation: Centre for Public Health Research, Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Peter
authors.initials: P
authors.lastname: Wanzala
authors.affiliation: Centre for Public Health Research, Kenya Medical Research Institute, Nairobi, Kenya.
authors.forename: Melvin
authors.initials: M
authors.lastname: D'Lima
authors.affiliation: Kenyatta National Hospital, Nairobi, Kenya.
authors.forename: Anthony
authors.initials: A
authors.lastname: Njiru
authors.affiliation: School of Dental Sciences, University of Nairobi, Nairobi, Kenya.
authors.forename: Mark
authors.initials: M
authors.lastname: Chindia
authors.affiliation: School of Dental Sciences, University of Nairobi, Nairobi, Kenya.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Dimba
authors.affiliation: Molecular Basis of Disease Research Program, Menzies Health Institute Queensland, Griffith University, Gold Coast, Qld, Australia.|Population & Social Health Research Program (Population Oral Health), Menzies Health Institute Queensland, Griffith University, Gold Coast, Qld, Australia.
authors.forename: Newell W
authors.initials: NW
authors.lastname: Johnson
mesh_terms: D000163:Acquired Immunodeficiency Syndrome; D000293:Adolescent; D000328:Adult; D000956:Antigens, Viral / Q000032:analysis / Q000235:genetics; D001706:Biopsy; D045744:Cell Line, Tumor; D002648:Child; D002675:Child, Preschool; D004279:DNA, Viral / Q000032:analysis; D003906:Developing Countries; D005260:Female; D019288:Herpesvirus 8, Human / Q000302:isolation & purification; D006801:Humans; D007150:Immunohistochemistry; D007630:Kenya; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D009687:Nuclear Proteins / Q000032:analysis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012514:Sarcoma, Kaposi / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000821:virology; D055815:Young Adult
chemical_list: D000956:Antigens, Viral; D004279:DNA, Viral; D009687:Nuclear Proteins; C109540:latency-associated nuclear antigen
keywords: Kaposi's sarcoma; diagnosis; histopathology; human herpesvirus 8; oral diseases