Metastatic urothelial carcinoma of the bladder with sarcomatoid differentiation showing large cell neuroendocrine transformation in the liver; an unusual behaviour of a rare disease.

Metastatic urothelial carcinoma of the bladder is generally considered to be an aggressive disease with many recognised variants, however what is unique about our patient is the metastatic transformation from a urothelial primary malignancy with sarcomatoid variation to a neuroendocrine deposit within the liver. From what we have identified, this pattern of pathological transformation has not been reported for a urothelial malignancy in the literature. We present a 64 year old male who we believe is the first reported case of a primary urothelial malignancy presenting de-novo with metastatic liver deposits showing neuro-endocrine transformation.

18F-FDG uptake in multiple splenic foci on PET/CT: an unusual case of visceral leishmaniasis.

A previously well 48-year-old male patient presented with several months of weight loss, fever, massive hepatosplenomegaly, and pancytopenia. A provisional diagnosis of lymphoma could not be confirmed on blind lymph node or bone marrow biopsies. Referral for 18F-FDG PET was made to identify an appropriate biopsy site. Focal uptake in multiple splenic lesions was seen, with normal FDG uptake elsewhere in the body. Splenectomy was then performed and histology revealed leishmaniasis, with no evidence of lymphoma. Focally FDG avid splenic deposits have never been reported in leishmaniasis and were likely due to nodular red pulp expansion.

The value of [18F]-fluorodeoxyglucose-positron emission tomography/CT scanning in the diagnosis of neurosarcoidosis.

Sarcoidosis is a granulomatous disease of unknown aetiology which primarily affects the lungs, but can affect other tissues including the central nervous system (CNS). In neurosarcoidodis, the CNS is often the only affected site, which makes a tissue diagnosis difficult. Although a clinical diagnosis of neurosarcoidosis can often be made, the wide range of potential differential diagnoses, including other steroid responsive conditions (such as idiopathic lymphocytic meningitis) means that a confirmed diagnosis is invaluable. This is particularly important because neurosarcoidosis has a poor prognosis and aggressive immunosuppressive treatment is generally recommended. We present a man with clinically suspected neurosarcoidosis where attempts to obtain histological confirmation of the disease through skin and meningeal biopsy was unhelpful, but a lymph node biopsy, directed with the use of [18F]-fluorodeoxyglucose-positron emission tomography/CT scanning was diagnostic.

Safety of radiofrequency ablation of myocardium and lung adjacent to the heart: an animal study.

BACKGROUND: The purpose of this work was to assess the feasibility and safety of applying radiofrequency to lung parenchyma adjacent to the heart and to evaluate the clinical impact and the histopathological damage to the heart caused by radiofrequency electrodes penetrating the pericardium and the myocardium. MATERIALS AND METHODS: Three sheep underwent pulmonary radiofrequency ablation adjacent to the heart at 460 kHz with target temperatures of 70 degrees C for 10 min at a maximum deployment of 4 cm. The animals were euthanized at the end of the procedure and the lungs and hearts were removed for gross pathological examination. Histopathology on selected hematoxylin & eosin-stained specimens was performed. RESULTS: Circulating blood had a "heat-sink" effect with tissue temperature at the electrode tips adjacent to the heart not exceeding 47 degrees C. Ventricular tachycardia and occasional extrasystoles were the only adverse reactions noted, even when electrodes penetrated the myocardium heart rhythm returned to sinus upon discontinuation of the radiofrequency energy delivery. CONCLUSIONS: Pulmonary radiofrequency ablation next to the heart is a relatively safe procedure. Major concern is that incomplete tumor ablation adjacent to the heart is probable as a result of the cooling effect of the circulating blood.