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Proliferating cell nuclear antigen (PCNA) expression in oral squamous cell carcinoma - an aid to conventional histological grading?

Zain RB, Sakamoto F, Shrestha P, Mori M

Malays J Pathol, 1995 Jun;17(1):23-30.
PMID: 8907001

Proliferating cell nuclear antigen (PCNA) is a well known marker for cell proliferation. It tends to accumulate in the late G1 and S-phase of the cell cycle. A monoclonal antibody (MoAb) against PCNA is now available and it can react with paraffin-embedded specimens. In the present study, PCNA immunohistochemical staining of 36 cases of oral cancer specimens obtained from surgery were investigated. The results showed differing nuclear staining patterns for PCNA in normal, hyperplastic and dysplastic epithelium, early cancer and 3 levels of differentiation for squamous cell carcinoma of the oral cavity. It appears that PCNA can be a useful marker in delineating normal epithelium and hyperplastic epithelium from dysplasia in the oral cavity. The use of PCNA staining may further emphasize the conventional histopathological grading of well-differentiated, moderately-differentiated and poorly-differentiated oral squamous cell carcinoma but is still dependent on basic criteria as observed without immunostaining. PCNA expression for all grades of squamous cell carcinoma are present at the deep, infiltrative margins.

Matched MeSH terms: Mouth Mucosa/pathology
Risk of the contralateral mucosa in patients with oral potentially malignant disorders

Siar CH, Mah MC, Gill PP

Asian Pac J Cancer Prev, 2011;12(3):631-5.
PMID: 21627356

BACKGROUND: It is known that abnormal changes may occur in any part of the oral mucous membrane exposed to a carcinogen. Therefore patients with oral potentially malignant disorders (PMDs) are at risk of developing similar lesions at multiple sites.
OBJECTIVES: To determine the risk of the contralateral mucosa in patients presenting with oral PMDs.
MATERIALS AND METHODS: Sixty individuals with PMDs were selected for this study. These comprised 32 (53.3%) Indians, 23 (38.3%) Chinese, four (6.7%) Malays and one (1.7%) Nepalese. All selected cases had histopathological confirmation of their primary existing lesion as inclusion criteria. Cases that subsequently presented with a lesion in the corresponding anatomical site also underwent scalpel incisional biopsy on this second lesion to verify its diagnosis. The remaining cases that presented with unilateral PMDs at the time of study were subjected to a cytobrush biopsy on the normal looking contralateral mucosa.
RESULTS: A total of 70 primary PMDs were detected in 60 patients. The most common PMD found was oral lichen planus (n=40, 57.1%). Of the 60 patients studied, 28 (46.6%) exhibited bilateral lesions either synchronously (n=21, 35.0%) or metachronously (n=7, 11.6%). The remaining cases that had undergone cytobrush biopsy on the corresponding anatomical site yielded normal cytological results.
CONCLUSIONS: Present findings demonstrated that patients presenting with PMDs in the upper aerodigestive tract are at a greater risk of developing a second lesion most probably in the contralateral anatomical site.

Matched MeSH terms: Mouth Mucosa/pathology*
Fulltext Squamous epitheliotropism of Enterovirus A71 in human epidermis and oral mucosa

Phyu WK, Ong KC, Kong CK, Alizan AK, Ramanujam TM, Wong KT

Sci Rep, 2017 03 21;7:45069.
PMID: 28322333 DOI: 10.1038/srep45069

Hand-foot-and-mouth disease is a self-limiting paediatric infectious disease commonly caused by Enterovirus A71 (Genus: Enterovirus, Family: Picornaviridae). Typical lesions in and around the hands, feet, oral cavity and other places may rarely be complicated by acute flaccid paralysis and acute encephalomyelitis. Although virus is readily cultured from skin vesicles and oral secretions, the cellular target/s of Enterovirus A71 in human skin and oral mucosa are unknown. In Enterovirus A71-infected human skin and oral mucosa organotypic cultures derived from the prepuce and lip biopsies, focal viral antigens and viral RNA were localized to cytoplasm of epidermal and mucosal squamous cells as early as 2 days post-infection. Viral antigens/RNA were associated with cytoplasmic vacuolation and cellular necrosis. Infected primary prepuce epidermal keratinocyte cultures showed cytopathic effects with concomitant detection of viral antigens from 2 days post-infection. Supernatant and/or tissue homogenates from prepuce skin organotypic cultures and primary prepuce keratinocyte cultures showed viral titres consistent with active viral replication. Our data strongly support Enterovirus A71 squamous epitheliotropism in the human epidermis and oral mucosa, and suggest that these organs are important primary and/or secondary viral replication sites that contribute significantly to oral and cutaneous viral shedding resulting in person-to-person transmission, and viraemia, which could lead to neuroinvasion.

Matched MeSH terms: Mouth Mucosa/pathology
The effects of betel-nut chewing on the buccal mucosa: a histological study

Lee KW, Chin CT

Br. J. Cancer, 1970 Sep;24(3):433-41.
PMID: 5475751

Sixty-two "leukoplakias" from the cheeks of betel-nut chewers in West Malaysia were studied histologically. Ten biopsies were from non-tobacco betel-nut chewers. An amorphous von Kossa positive layer was seen on the keratin surface in 42 specimens. Tobacco did not appear essential for its formation, and it appeared to be significantly associated with parakeratosis. Its possible significance as a cuticle-like layer prolonging contact between carcinogens and the mucosa is discussed.Parakeratosis appeared to be the most common form of cornification seen, and the mitotic activity in parakeratinized leukoplakias appeared to be significantly greater than orthokeratinized leukoplakias.Comparison with studies on other population samples using different quids suggested that severe histological changes were more likely to be seen when tobacoo-containing quids were chewed as compared to non-tobacco-containing quids.An attempt to correlate the histological changes seen with the clinical habit in leukoplakias from chewers using tobacco-containing quids suggested that epithelial atrophy appeared to be significantly related to the duration of the habit but not to the "intensity" of the habit.

Matched MeSH terms: Mouth Mucosa/pathology*
p53 Expression as a marker of microinvasion in oral squamous cell carcinoma

Heah KG, Hassan MI, Huat SC

Asian Pac J Cancer Prev, 2011;12(4):1017-22.
PMID: 21790244

INTRODUCTION: Oral squamous cell carcinoma (OSCC) has high local recurrence, partly caused by the lack of clear margin identification on surgical removal of cancerous tissues. Direct visualization by immunostaining and fluorescent in situ hybridization (FISH) in tissue sections gives more definite information about genetic damage at margins with appropriately selected biomarkers.
AIMS: To determine the usefulness of immunohistochemical techniques and FISH of the tumour suppressor TP 53 gene to identify microinvasion in marginal tissue sections and to relate the possible correlation between protein expression and genetic aberrations in OSCC cases in Malaysia.
METHODS: Immunohistochemistry and FISH of TP 53 genes were applied on 26 OSCC formalin fixed paraffin embed (FFEP) blocks selected from two oral cancer referral centers in Malaysia.
RESULTS: For p53 protein immunohistochemistry, 96% of the 26 OSCC studied showed positive immunostaining at the excision margins. In FISH assay, 48.9±9.7% of the cancerous cells were monoploid for p53 probe signals, 41.0±9.5 % were diploid, and 10.2±7.8 % were polyploid. A correlation between p53 immunostaining and TP53 gene aberrations was noted (p< 0.05).
CONCLUSIONS: Immunohistochemical analysis of p53 protein expression and FISH of TP53 gene could be applied as screening tool for microinvasion of OSCC.

Matched MeSH terms: Mouth Mucosa/pathology