Sporadic malignant nerve sheath tumour of the oculomotor nerve.

Malignant peripheral nerve sheath tumours (MPNST) are exceedingly rare in an intracranial location. In this report clinical and pathological evidence for the diagnosis of a MPNST arising from of the oclumotor nerve is presented. To our knowledge this is the first such case reported in the medical literature.

Communication between peritoneal cavity and mediastinal lymph nodes demonstrated by Tc-99m albumin nanocolloid intraperitoneal injection.

Lymphatic drainage from the peritoneal cavity to mediastinal lymph nodes has been reported, indicating that abdominal fluid is not immobile. We studied this movement in rats receiving Tc-99m albumin nanocolloid which has smaller particle sizes than does Tc-99m microaggregated albumin colloid used for liver/spleen imaging. The Tc-99m albumin nanocolloid had a radiochemical purity of 99.33%-99.77% with free pertechnetate of 0.23%-0.67%. During pentobarbital anesthesia, thoracoabdominal images were obtained 4-6 hr after intraperitoneal injection of 350 mCi Tc-99m albumin nanocolloid with 5 ml of normal saline. The images showed symmetrical radiotracer localization in the mediastinal lymph nodes. Scintigraphic demonstration of drainage to the mediastinal region from the peritoneal cavity may be explained by flow directly into mediastinum through the lymphatic system, indicating lymphatic patency between the peritoneal cavity and mediastinum. Absence of visualization may indicate lymphatic block. This type of information concerning lymphatic drainage may have clinical impact for a patient with malignant or intractable ascites. The radionuclide technique is easily performed for this assessment.

Modified in vivo behaviour of 99mTc-labelled liver-spleen preparations due to 99Mo/99mTc-generator eluate impurities.

At irregular intervals, a 99mTc-labelled microcolloid for liver and spleen scintigraphy was reported to accumulate in the lungs, in the absence of any pathophysiological condition usually associated with this phenomenon. These findings were in direct contrast to the results obtained during quality control assays performed on the production batches of the kit. The authors tested the hypothesis that the presence of Al3+ ions in the generators eluate used to label the kit caused the formation of larger size aggregates. The experimental results suggest that the 99mTc-pertechnetate solution used for labelling contained far more than 40 micrograms Al3+ per ml, hence a many-fold increase of the maximum level tolerated by the pharmacopoeia. The authors advise caution when interpreting findings of pulmonary activity in the absence of clear evidence of pathological conditions that are sometimes associated with this biodistribution pattern.