Microsatellite instable vs stable colon carcinomas: analysis of tumour heterogeneity, inflammation and angiogenesis.

BACKGROUND: Microsatellite instability (MSI) accounts for 15% of all colorectal tumours. Several specific clinicopathologicals (e.g., preference for the proximal colon over the distal colon, improved prognosis and altered response to chemotherapeutics) are described for this subset of tumours. This study aimed to analyse morphological, inflammatory and angiogenic features of MSI vs microsatellite stable (MSS) tumours. METHODS: Twenty-seven MSS and 29 MSI, TNM stage matched, colorectal tumours were selected from the archive of the Department of Pathology, UZ Leuven. Morphology was analysed on haematoxylin-eosin sections. Immunohistochemistry for CD3, CD4, CD8, CD20 and CD68 was used to map tumour infiltration in both a digital and traditional microscope-based manner for all distinct morphological components of the tumour. CD31 immunostains were performed to assess angiogenesis. RESULTS: Morphological tumour heterogeneity was a marked feature of MSI tumours, occurring in 53% of the cases as compared with 11% of the MSS tumours (P<0.001). Digital immune quantification showed an increased number of tumour-infiltrating cytotoxic T-lymphocytes (CD8+) in MSI compared with MSS tumours for both the tumour (P=0.02) and peritumoural area (P=0.03). Traditional microscope-based quantification confirmed these results (P<0.001 for both) and, in addition, revealed large numbers of CD68+ macrophages in the peritumoural area of MSI cancers (P=0.001). Moreover, traditional microscope-based analysis was able to distinguish between lymphocytes directly infiltrating the tumoural glands (intra-epithelial) and those infiltrating only the neoplastic stroma around the glands (intratumoural). Quantification showed high numbers of intra-epithelial CD3+, CD4+, CD8+, CD20+ and CD68+ cells in MSI compared with MSS cancers (P<0.001, P=0.01, P<0.001, P<0.001 and P=0.006, respectively). Higher microvessel density (MVD) was observed in MSI tumours compared with their MSS counterpart. CONCLUSIONS: Mixed morphology, reflecting tumour heterogeneity, is an important feature of MSI tumours and may have both diagnostic and therapeutic impact. The inflammatory reaction also presented with significant differences in MSI vs MSS colorectal tumours. MSI cancers showed mainly infiltration by cytotoxic T-cells in both the tumour and the close border around the tumour, as well as increased intra-epithelial infiltration in contrast to MSS tumours. The type of immune cell and the compartment it resides in (intratumoural or intra-epithelial) depend both on MSI status and morphology. Finally, MSI tumours showed a higher angiogenic capacity represented by an increased MVD, hinting for possible therapeutic consequences.

[Intra-arterial thrombolysis of a basilar vascular accident during coronary angiography]. / Thrombolyse intra-artérielle d'un accident vasculaire basilaire au cours de la coronarographie.

The authors report the case of a 67 year old man with a previous history of aortobifemoral arterial graft who had unstable angina after carotid endarterectomy. Coronary angiography by the right brachial artery was complicated by a cerebrovascular accident with a reactive coma, convulsions and respiratory problems. Selective angiography of the right vertebral artery showed an image of occlusive thrombosis of the basilar artery. In view of the clinical state and angiographic appearances, the authors decided on immediate intra-arterial thrombolysis with Urokinase which dissolved the clot and reestablished flow in the basilar artery, the cerebellar and posterior cerebral arteries. The outcome was favourable with immediate and good recovery of consciousness and hospital discharge on the sixth day without neurological or radiological sequellae. Cerebrovascular accident is a rare and potentially serious complication of left heart catheterisation which requires immediate cerebral angiography to determine the mechanism and propose an appropriate therapeutic approach.

[Human leptospirosis in Reunion Island. A 3-year epidemiological study (1985-1987)]. / La leptospirose humaine à la Réunion. Etude épidémiologique sur trois années (1985-1987).

During a three-year period (1985-1987), in Reunion Island, 252 cases of leptospirosis were clinically diagnosed in humans, and serologically confirmed. The epidemiological study showed a significant male predominance, presence during all ages of life; no month and no geographical zone are spared but maximal incidences are noted during periods of and in localities with the most important rainfall. Severe forms are frequent but mortality remains low.