Hyperplastic colorectal polyp: histological, histochemical and immunohistochemical study of 43 cases

Forty-three solitary hyperplastic polyps removed from the colon or the rectum (HPC) were examined under light microscopy. A histochemical and immunohistochemical study was undertaken in order to evaluate semiquantitatively the nature and the distribution of epithelial mucins and the secretion of carcinoembryonic antigen (CEA). Ten HPC had a peculiar morphologic pattern (four with regenerative dysplasia and six with adenomatous foci). CEA secretion was always increased (37 per cent of cases) or highly increased (63 per cent of cases) with respect to the normal colonic mucosa. The nature and distribution of the secreted acid mucins were modified: sulfomucin was equal (25 per cent of cases) or higher (75 per cent of cases) than that in normal rectal or sigmoid colonic mucosae; sialomucin was strongly decreased in 91 per cent of cases. Some of these functional changes (CEA) are also observed in neoplastic lesions. These findings are not in accord with the hypothesis that hyperplastic polyp is a simple hyperplasia of the mucosal epithelium and suggest a disorder in cellular differentiation, particularly for the larger polyps.     

Late Onset of Chronic Granulomatous Disease Revealed by Paecilomyces lilacinus Cutaneous Infection

Chronic granulomatous disease (CGD) is an inherited immunodeficiency due to defective leukocyte NADPH responsible for recurrent infections and aberrant inflammation. Mutations in the CYBB gene are responsible for the X-linked CGD and account for approximately 70% of the cases. CGD is diagnosed during childhood in males. Female carriers may have biased X-inactivation and may present with clinical manifestations depending on the level of residual NADPH oxidase activity. We report the case of a previously asymptomatic female carrier who was diagnosed at age 67 with a skin infection with the rare fungus Paecilomyces lilacinus as the first manifestation of CGD. Dihydrorhodamine 123 (DHR) activity was below 10%. Next-generation sequencing (NGS) revealed mutations in DNMT3A, ASXL1, and STAG2 suggesting that clonal hematopoiesis could be responsible for a progressive loss of NADPH oxidase activity and the late onset of X-linked CGD in this patient. Long-term follow-up of asymptomatic carrier women seems to be essential after 50 years old.

     

Histochemical study of mucosubstances in carcinoma of gastric remnant

Twenty patients with carcinoma of the gastric remnant after surgery for benign disease have been studied. The histologic and histochemical data on gastric mucosa surrounding the carcinoma have been compared with data from 60 biopsy samples taken from gastric stumps without carcinoma in an age-and sex-matched group. There was a high incidence of intestinal metaplasia in the gastric stumps (24 of 60); it was even higher in the cases with a carcinoma (17 of 18). Intestinal metaplasia Type III, which is closely related to the carcinoma in a stomach not surgically treated, was rare in cases of cancer in the gastric stump (1 in 18). This finding is correlated to the high frequency of the diffuse type of carcinomas that occur in the gastric stump (15 of 20), which are rarely associated with intestinal metaplasia. Therefore, identifying intestinal metaplasia types does not always point to the fact that affected patients will also be at high risk for cancer in their gastric remnant.     

Lack of cilia and differentiation defects in the liver of human foetuses with the Meckel syndrome

Background/Aims: Meckel syndrome is an autosomal‐recessive disease characterized by a combination of renal cysts, anomalies of the central nervous system, polydactyly and ductal plate malformations (DPM), which are hepatic anomalies consisting of excessive and abnormal foetal biliary structures. Among the genomic loci associated with Meckel syndrome, mutations in four genes were recently identified. These genes code for proteins associated with primary cilia and are possibly involved in cell differentiation. The aim of the present work was to investigate the formation of the primary cilia and the differentiation of the hepatic cells in foetuses with Meckel syndrome. Methods: Sections of livers from human foetuses with Meckel syndrome were analysed by immunofluorescence, immunohistochemistry and electron microscopy. Results: The primary cilia of the biliary cells were absent in some Meckel foetuses, but were present in others. In addition, defects in hepatic differentiation were observed in Meckel livers, as evidenced by the presence of hybrid cells co‐expressing hepatocytic and biliary markers. Conclusions: Defects in cilia formation occur in some Meckel livers, and most cases show DPM associated with abnormal hepatic cell differentiation. Because differentiation precedes the formation of the cilia during liver development, we propose that defective differentiation may constitute the initial defect in the liver of Meckel syndrome foetuses.