p21 and p27 immunoexpression in gastric well differentiated endocrine tumors(ECL-cell carcinoids)

AIM： To investigate the expression of cyclin-dependent kinase inhibitors p21 and p27 in gastric well differentiated endocrine tumors （GWDET） （ECLocell carcinoids）.METHODS： The expressions of p21 and p27 were examined immunhistochemically in endoscopic biopsy specimens from 16 patients matching the diagnostic criteria of GWDET. Percentage of positive nuclear staining either weak or strong was noted. The association of immunoexpressions with age, gender, tumor localization, multifocality and accompanying chronic atrophic gastritis, neuroendocrine cell hyperplasia （NEH）, neuroendocrine dysplasia （NED）, intestinal metaplasia （IM）, Ki-67 proliferation index and clinical outcome were also evaluated.RESULTS： All cases expressed p27 with a mean expression score of 43.6%, while 31.3% of the cases showed any p21 expression, p21 and p27 immunoexpressions were significantly correlated with each other （P 〈 0.01）, and the p21-expressing group had higher p27 expression scores （68% vs 22%）. p21 and p27 expressions were lower in women, in non-atrophic mucosa and cases whose tumors were located somewhere other than fundus without submucosal extension. On contrary, p21 and p27 expressions were higher in males and the patients with submucosal extension and atrophic gastritis. Cases presenting lower p27 scores had solitary tumors showing neither NEH-NED nor IM. Despite, cases with lower p21 expression presented multifocal tumors accompanied by NEH-NED. However, no correlation of p21 and p27 expressions was found with age and Ki-67 expression.CONCLUSION： p27 is widely expressed in GWDETs, while p21 expression is sparse and observed in two thirds of the cases. Loss of p21 and p27 expressions may be correlated with different carcinoid tumor subtypes; however,more studies are needed to assess the role of these prospective markers in gastrointestinal endocrine tumors.

Digitally reinforced hematoxylin-eosin polarization technique in diagnosis of rectal amyloidosis

AIM:To investigate the efficacy of the digitally reinforced hematoxylin-eosin polarization(DRHEP)technique for detection of amyloidosis in rectal biopsies.METHODS:One hundred hematoxylin-eosin(HE)stained rectal biopsies with Congo-red(CR)-positive amyloid depositions and 50 control cases with CRnegative amyloid-mimicking areas were scanned blinded to the CR results for amyloid depositions under both bright and polarized light,and digitally photographed using the DRHEP technique,to accentuate the faint birefringence observed in HE slides under polarization.The results of DRHEP and HE evaluation were statistically correlated with CR polarization results with respect to presence and localization of amyloid deposits as well as amyloid types.RESULTS:Amyloid deposits showed yellowish-green birefringence by DRHEP,which allowed identification of amyloidosis in 41 HE-unsuspected cases(P=0.016),31 of which only had vascular deposits.True positivity was higher,and false negativity and positivity were lower by DRHEP,compared to evaluation by HE(69%,31%,and 0.8%vs 33%,67%,and 33%,respectively;P<0.0001).The sensitivity,specificity,accuracy,and positive and negative predictive values for DRHEP were69%,98%,78.6%,98.5%,and 61.25%,respectively.Reasons for DRHEP false negativity were presence of extensive background birefringence in 12 cases,absence of CR birefringent vessel in 3 cases,and missing of the tiny deposits in 9 cases,which could be improved by experience,especially in the latter case.No correlation was found between age,gender,sites of deposits,or amyloid types.CONCLUSION:The DRHEP technique improves diagnostic accuracy when used as an adjunct or a prior step to CR staining,especially for cases with limited tissues for further analysis.