p21 expression in colorectal carcinomas: a study on 103 cases with analysis of p53 gene mutation/expression and clinic-pathological correlations

The WAF1/CIP1 gene product, p21, an inhibitor of cyclin-dependent kinases, is a critical downstream effector in the p53 pathway. The expression of p21 in human neoplasms is heterogeneous, and may be related to p53 functional status. We evaluated p21 immunoreactivity in 103 colorectal carcinomas (CC) in relation to the p53 gene and protein alterations and clinico-pathologic parameters. High p21 expression (more than 10% reactive cells) was seen in 39% of cases. p21 staining was heterogeneous and often detected in clusters of tumour cells; in some tumours p21 staining was more pronounced in superficial areas. No relation was seen between p21 immunoreactivity and site of the tumours (right vs left), TNM stage and grade. p21 expression was related to p53 status as evaluated with IHC or with SSCP analyses, low p21 expression usually being associated with p53 protein overexpression (P=0.048) and p53 gene alteration (P=0.005). The strongest associations were seen when the combined p53/p21 immunophenotype was compared with p53 gene alterations (P=0.0002). These data support the hypothesis that p21 expression in CC is mainly related to p53 functional status, suggesting that p21 expression could be an interesting adjunct in the evaluation of the functional status of the p53 pathway in CC.

[Laryngeal malignant schwannoma in a 9-year-old boy: report of a clinical case]

A case of malignant schwannoma of the larynx in a 9 year old boy is reported. The lesion recurred 29 months later with the same histological pattern. The malignant peripheral nerve sheath tumours of the larynx are rare and are almost exceptional in paediatric age. The Authors discuss the main differential diagnosis of spindle cell paediatric tumors of the laryngeal region.

[Localized amyloidosis of the larynx]

Localized laryngeal amyloidosis is a rare laryngeal disease which accounts for less than 1% of all benign laryngeal tumors. The symptoms depend on where the amyloid deposit is located in the larynx. When the vocal cords are involved there may be some hoarseness; pain or increasing difficulty in inspiration may arise when, respectively, the aryepiglottic fold or subglottic space are involved. The present paper reports a case of laryngeal amyloidosis without any sign of systemic disease. It also deals with the principle diagnostic procedures to follow. After a review of the literature, emphasis is placed on how important it is to recognize laryngeal amyloidosis in order to achieve an appropriate diagnosis and plan therapy properly. Surgery is the main treatment using either endoscopy or an external neck approach. Recently CO2 laser surgery has been used successfully. Prognosis depends on both the size of the amyloid deposit and whether there is some simultaneous overall involvement.

Expression of carcinoembryonic antigen in ulcerative colitis, tubular adenomas and hyperplastic polyps: correlations with the degree of dysplasia

Sections of tubular adenomas (n = 40), ulcertive colitis (n = 97) and hyperplastic polyps (n = 31) were examined by immunoperoxidase staining to carcinoembryonic antigen (CEA) in order to assess its potential diagnostic value in predicting malignant potential of these lesions. We compared the degree of epithelial abnormality in these mucosal specimens with the extent of immunoperoxidase staining for CEA. We found that CEA staining correlated with the degree of epithelial alteration in tubular adenoma and ulcerative colitis groups. Scattered weakly positive staining was found in eight of 31 hyperplastic polyps. High tissue expression of CEA, when combined with histologic dysplasia, may prove to be an additional factor in the evaluation of malignant potential in ulcerative colitis specimens and adenomas.

[Primary neuroendocrine carcinoma of the skin (Merkel cell tumor)]

Three cases of neuroendocrine carcinoma of the skin studied by light and electron microscopy and by immunohistochemical methods, are presented. It is generally accepted that these tumors originate from Merkel's cells. Some consider that they belong to the group of APUD-omas. Positive findings of epithelial (EMA, CAM 5.2) and neuroedocrine marker (NSE) in these three cases support the hypothesis of neuroendocrine differentiation in a neoplasm of epithelial origin.

Investigation of the Applicability of Histological Classification of Bronchial Carcinoma According to the World Health Organization

According to the World Health Organization histological classification of bronchial tumors, clear and giant cell carcinomas are two subtypes of large cell carcinoma. As clear and giant cells can also be observed in other types of bronchial carcinoma, we investigated the frequency of the finding of these cells in different histological types. The tumor size and degree of differentiation, the amount of necrosis and keratinization, and the presence of giant and clear cells were analyzed. Statistical analysis by χ2 test showed (for all classified histological types of bronchial carcinomas, except small cell carcinoma) that: 1) larger tumors had a great quantity of giant cells (P < 0.05; P < 0.01), 2) large tumors had more clear cells (P < 0.05; P < 0.01) and 3) tumors with a greater amount of necrosis had a larger number of giant and clear cells (P<0.05; P < 0.01). Findings of an identical cytological characteristic can cause some difficulty in determination of bronchial cancer.