Basaloid carcinoma of the colon arising at the splenic flexure.

AIMS: Basaloid carcinomas typically arise in the anal canal and there are only three well-documented cases of this neoplasm reported outside the anal canal, none more proximally than the sigmoid colon. The first occurrence of a basaloid colonic carcinoma arising outside the sigmoid colon, at the splenic flexure, is presented. METHODS AND RESULTS: A splenic flexure mass was resected from a 54-year-old man with a 3-week history of abdominal discomfort, diarrhoea and weight loss. This tumour, like typical anal canal basaloid carcinomas, was composed of islands of basaloid cells with peripheral nuclear palisading; within many islands there was central necrosis and focal squamous differentiation. Ultrastructural and immunohistochemical studies confirmed the basaloid nature and focal squamous differentiation within this neoplasm. Basaloid carcinoma of the anal canal has been associated with human papilloma virus. Using in-situ hybridization, HPV DNA was not detected in this case. CONCLUSIONS: Outside the anal canal, it has been postulated that basaloid colonic carcinomas may arise from cloacogenic embryologic rests, squamous metaplastic epithelium, or totipotential basal cells. The location and pathological findings of this tumour suggest that this rare colonic neoplasm arises from a totipotential basal cell.

Fatal streptokinase-induced intracerebral haemorrhage in cerebral amyloid angiopathy.

A fatal intracerebral haemorrhage (ICH) associated with streptokinase (SK) treatment of an acute myocardial infarction is described. Autopsy examination showed a lobar ICH and severe cerebral amyloid angiopathy (CAA). The close temporal relationship between SK administration and intracranial haemorrhage, the absence of pretreatment risk factors for ICH, and the presence of CAA suggests that these are related phenomena. Accordingly: 1. There may be a synergistic relationship between CAA and intracranial haemorrhage induced by fibrinolytic agents; 2. Thrombolytic agents may induce more frequent than expected intracranial haemorrhage in conditions associated with a high incidence of CAA, notably old age and Alzheimer's disease; 3. A regional defect in haemostasis other than vessel fragility may contribute to the intracranial haemorrhagic predisposition of CAA; 4. Autopsy examination of cases of ICH is an essential part of the audit of clinical trials of fibrinolytic agents.