[Dysplasia in glandular digestive tissues: new concepts, new classifications]

[Dysplasia in gastrointestinal mucosa: Interobserver variability and value of histological examination in the diagnosis of these lesions]

Dysplasia is a preneoplastic lesion. Histological diagnosis is based on the presence of architectural and cytological modifications, and dedifferentiation, which the intensity is variable. Dysplasia is commonly graded as low and high grade. We achieved a retrospective study of 90 cases of gastrointestinal dysplasia collected in the Department of Pathology of Hassan II university hospital of Fez, during a period of 3 years. The cases were reviewed independently and blindly without clinical information by two pathologists. Their diagnoses were compared to the initial diagnosis. Interobserver concordance in the diagnosis of the degree of dysplasia was evaluated. The average age of our patients was 56 years oldwithout predominance of sex. The interobserver concordance in the diagnosis of digestive dysplasia between the three pathologists was moderate (with a Kappa estimated at 0.42). Concordant diagnosis for digestive low grade dysplasia was observed in 50 cases of the 55 cases (90%) and only 18 cases of high-grade dysplasia of 35 cases studied (50%). The agreement for the low-grade dysplasia is more significant. However, there is significant variation in the analysis of high-grade dysplasia. This work reveals a moderate reproducibility in the diagnosis of gastrointestinal dysplasia lesions and mostly well marked for high-grade dysplasia.

[Aero-digestive tract squamous intra-epithelial neoplasia]

Aero-digestive tract squamous intra-epithelial neoplasia is a disease whose genetic and epigenetic features lead to clinical signs and well codified histologic features. This publication aims to review the molecular alterations which have been identified in these lesions, to clarify the clinical manifestations and to discuss the proposed histological classification.

Development of Cryptosporidium parvum-induced gastrointestinal neoplasia in severe combined immunodeficiency (SCID) mice: severity of lesions is correlated with infection intensity

We reported previously that Cryptosporidium parvum was able to induce intestinal tumors in severe combined immunodeficiency (SCID) mice treated with corticoids. To further characterize this Cryptosporidium-induced cell transformation, SCID mice treated with dexamethasone were challenged with C. parvum oocysts, and euthanatized sequentially after infection for histologic examination. Ki-67 was used as a marker of cellular proliferation. Our previous results were confirmed, and it was also found that mice receiving higher inocula (10(6)-10(7)) experienced more severe neoplastic development. Additionally, neoplastic changes were observed not only in the caecum but also in the stomach and duodenum of some animals. Interestingly, SCID mice (6/6) inoculated with 10(5)-10(7) oocysts showed high grade intraepithelial neoplasia or adenomas with high grade dysplasia in the caecum after Day 46 post-infection (PI). Immunohistochemistry for Ki-67 staining indicated the neoplastic process associated to cryptosporidiosis, and evidenced the first immunohistochemical alterations at early stages of the process, even at 3 weeks PI.

[Handling and reporting of endoscopic specimens of gastrointestinal neoplastic lesions]

Endoscopic mucosal resection is now widely used for the treatment of superficial neoplastic lesions of the digestive tract. The pathological examination of the specimens provided by endoscopic resections is essential for evaluation of the quality and safety of the resection, identification and description of the lesion, search for massive invasion and, if necessary, assessment of the depth of invasion. Such information is pivotal for determining whether the endoscopic resection is safe or if a complementary surgical treatment is needed. In this review, based on recently published international recommendations, we describe the technical procedures required for optimal handling and processing of the specimens and the information which must be found in the final report.