Pseudomelanosis duodeni is seen endoscopically as dark spots in the duodenal mucosa and is generally considered to be local deposition of iron from oral iron intake. However, pseudomelanosis duodeni may be identified histologically even before it becomes endoscopically evident; iron stainability within the mucosa is uneven and unpredictable, and multiple clinical conditions other than oral iron intake may be associated. We reviewed 17 adult patients with histologically detected pseudomelanosis duodeni, their endoscopic appearances, iron stainability, and clinical findings including oral iron and drug intake. Only 6/17 (35 %) had endoscopically apparent dark spots. Perl's iron stain was entirely positive in 18 %, partially positive in 64 %, and negative in 18 % of cases. History of oral iron was present in 76 % of patients, but other clinical conditions consistently associated were hypertension in 88 %, end stage renal disease in 59 %, and diabetes mellitus in 35 % of patients.

Patients with ESRD had less severe hepatitis C than did control subjects. Clinical measurements did not predict histologic findings in renal transplant candidates. Transjugular liver biopsy should be considered to stage hepatitis C in renal transplant candidates due to the risk of percutaneous biopsy in uremic patients.

A posterior fossa tumour in a 3 year old child is presented with characteristic histological, ultrastructural and immunohistochemical features of rhabdoid tumour. Many tumour cells contained cytoplasmic eosinophilic hyaline inclusions. Ultrastructurally concentric whorls of 10 nm intermediate filaments were identified. Immunohistochemical staining disclosed vimentin, cytokeratin and epithelial membrane antigen positivity. Renal and extrarenal rhabdoid tumours have been well documented but a primary rhabdoid tumour of the brain is extremely rare. Additional ultrastructural features seen were tubular crystalline inclusions in endoplasmic reticulum and abnormal large mitochondria.