Browsing by Author "Schneider, Johann W."

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    An Evaluation of High‑Risk HPV in Squamous Cell Carcinomas of the Lip in a South African Cohort
    (Springer Nature, 2024-05-06) Harbor, Sharon N.; Schneider, Johann W.; Solomons, Nadine; Sanderson, Micheline; Afrogheh, Amir H.
    Background To determine the prevalence of HR-HPV in a series of lip SCC from South African patients, using currently accepted HPV-testing methodologies and to define the clinical and histomorphologic features of HPV-associated lip SCC. Methods Fifty SCC of lip and 50 control cases were tested for HR-HPV using p16 and HR-HPV DNA PCR. p16-equivocal/positive and HPV DNA PCR-positive SCC were further evaluated for the expression of HPV-16 and HPV-18 mRNA transcripts using reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) to confirm transcriptionally active HPV. Results p16 was positive in 22% (n = 11) and equivocal in 4% (n = 2) of the SCC. One p16-positive case showed positivity for both HPV-16 DNA and HPV-16 E6/E7 mRNA transcripts (HPV prevalence rate of 2%). The HPV-positive case was non-keratinizing and occurred in an 80-year-old female. The two p16-equivocal cases were HR-HPV DNA positive and mRNA PCR negative. p16 was found to have a positive predictive value of 9%. Conclusion Findings from our cohort of lip SCC suggest that HR-HPV may have an insignificant role in the pathogenesis of SCC at this site. Due to its low ppv, p16 is insufficient to establish HR-HPV infection in SCC of the lip. The combination of p16 and DNA PCR appears to correlate with the presence of transcriptionally active virus. HPV E6/E7 mRNA detection is the gold standard for identifying HR-HPV. mRNA testing is not widely available in sub-Saharan Africa due to technical and financial constraints; however, the test appears to be of great value in p16-equivocal lip SCC.
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    Histological and immunohistochemical evaluation of sentinel lymph nodes in breast cancer at a tertiary hospital in the Western Cape, South Africa
    (Health & Medical Publishing Group, 2016-04-19) Van Zyl, Adri; Schneider, Johann W.
    Background. Breast carcinoma remains the most prevalent cancer among women, with over 300 000 deaths annually worldwide. Axillary lymph node status is essential for the clinical staging of breast carcinoma and remains the single most important predictor of disease-free survival in breast carcinoma. Objective. To determine effective histological examination of sentinel lymph node (SLN) sections for the detection of metastatic breast carcinoma. Methods. A prospective hospital-based study was done, including 20 patients with confirmed infiltrating breast carcinoma who underwent tumour excision or simple mastectomy as well as SLN biopsies. All the lymph nodes harvested were sectioned and embedded. Three sets of 15 consecutive serial sections were prepared from each case at one sitting, each measuring 3 - 5 μm in thickness and mounted on separate slides. Each set of 15 consecutive sections was grouped into three levels, each comprising 5 serial sections. The first 4 sections were stained with haematoxylin and eosin (H&E). The fifth section was stained for pancytokeratins, using MNF116. Results. Twenty patients who met the inclusion criteria of this study underwent SLN biopsies and simple mastectomies or tumour excisions. Twelve SLNs of 11 patients contained metastatic carcinoma, all detected at level I, with one case requiring MNF116 immunohistochemistry staining, revealing metastatic carcinoma, measuring 0.08 × 0.08 mm (micrometastases). The size of metastatic carcinoma ranged between 0.08 × 0.08 mm (micrometastases) and 25 × 15 mm. Nine cases showed macrometastases, varying in size between 2 × 3.5 mm and 25 × 15 mm. Tumour sections of three patients with infiltrating carcinoma, of no specific type (NST), revealed lymphovascular invasion. The breast tumour sizes of these cases measured 40 × 25 mm (1/1 node involved), 30 × 20 mm (1/3 nodes involved) and 15 × 12 mm (1/1 node involved), respectively. Nine patients (19 nodes in total, mean 2.1, range 1 - 5) did not have demonstrable metastatic disease in the 45 sections of levels I - IX, including MNF116 on every fifth section. Patients with negative SLNs varied in age between 29 and 68 years and had breast tumour sizes ranging between 10 × 10 mm and 30 × 30 mm, respectively. Conclusion. This study supports a conservative and cost-effective approach that comprises embedding of the entire SLN and the histopathological examination of four H&E-stained sections, which will usually demonstrate metastatic carcinoma. In the event of absence of metastatic carcinoma, immunohistochemical staining for pancytokeratin will detect tumour cells in a small percentage of cases. Examination of additional H&E- or pancytokeratin-stained sections is not cost effective. This finding can guide decisions pertaining to protocols for the histopathological assessment of SLN in breast carcinoma especially in resource-limited settings.
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    Tuberculosis and phrenic nerve destruction
    (Health and Medical Publishing Group (HMPG), 2007-08) Dempers, Johan J.; Bezuidenhout, Juanita; Schneider, Johann W.; Janse van Rensburg, Michele
    ENGLISH ABSTRACT: Phrenic nerve palsy (PNP) is often associated with Mycobacterium tuberculosis-related expansile pneumonia, possibly because of nerve entrapment by healing fibrosis. Mohan and Jayaswal1 postulated that pressure on the left phrenic nerve by an enlarged hilar lymph node caused unilateral diaphragmatic paralysis in a 6-year-old boy who developed PNP during the course of pulmonary tuberculosis (PTB). Gie et al. described 6 childhood cases of PTB complicated by unilateral PNP. The children did not recover on antituberculosis drugs and steroids, or in 1 case, after surgical decompression. Therefore the theory of glandular compression alone does not adequately account for PNP as a complication of PTB. Our case, in which the fate of the phrenic nerve was confirmed, provides strong evidence that destruction of the phrenic nerve by the tuberculous inflammatory process is involved in the pathogenesis of diaphragmatic paralysis, which may influence the clinical management of these children.