Diagnostic challenges of oral and cutaneous Kaposi's sarcoma in resource-constrained settings.

OBJECTIVES: 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. CONCLUSION: 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.

Clinicopathologic features of ameloblastoma in Kenya: a 10-year audit.

This study describes the clinical and pathologic features of ameloblastomas seen in the 2 main craniofacial treatment centers in Kenya in the 10-year period between January 1995 and December 2005. A total of 184 patient records were analyzed for this study. Eighty-two (44.6%) of the patients were male, and 102 (55.4%) were female with an overall age range of 10 to 80 years (mean, 30.2 years; SD, 14.1 years). There was no significant difference in gender presentation of ameloblastomas, although females presented at a slightly older age. The mean age for males was 29.9 years, and for females, it was 30.5 years. Patients generally tended to seek medical advice late, with the mean duration at first presentation of 46.3 months for males and 44.4 months for females. Most of the ameloblastomas (n = 172; 93.5%) were located in the mandible, 11 (6.0%) were in the maxilla, and 1 (0.5%) was in the soft tissues. Presenting symptoms included swelling (n = 182; 98.9%), pain (n = 64; 36.0%), mobile teeth/history of extraction (n = 104; 57.5%), purulent discharge (n = 39; 21.7%) and paresthesia (n = 10; 5.6%). The posterior mandible was the most commonly affected site, whereas maxillary ameloblastomas tended to occur in anterior sites. One hundred fifty-three ameloblastomas (83.2%) were of the solid/multicystic subtype; 8 (5.3%) were unicystic; 1 (0.5%) was of extraosseous origin; 1 (0.5%) was desmoplastic; 9 (6.0%) were malignant, and 12 of the records had no histopathologic pattern specified.