Round cell sarcoma of the colon with CIC rearrangement.

BACKGROUND: The CIC-rearranged sarcoma is a very rare highly aggressive malignant soft tissue group of tumors. It has recently been described as highly aggressive soft tissue tumors of children and young adults sharing similar morphological features with the Ewing sarcoma. The digestive localization is exceptional. CASE PRESENTATION: A 14-year-old male presented with a history of abdominal pain for 1 year, which increased in intensity over the last 2 months. Imaging findings showed a large heterogeneous mesenteric mass on the left flank of the abdomen. Exploratory laparotomy was performed and revealed a large cystic hypervascularized mass depending on the transverse colon and mesocolon. A wide excision of the lesion was performed with segmental colectomy. No postoperative complications were noted. The microscopic examination revealed a vaguely nodular growth of undifferentiated small round cells, arranged in solid sheets separated by thin fibrous septa with a scarce stroma. After an uncomplicated post-operative course, the patient was referred for chemotherapy. The patient died 2 months later with a peritoneal and pleural progression. CONCLUSIONS: The CIC-rearranged sarcoma is an aggressive tumor. There is no standard therapy for this rare disease. Their treatment includes surgery and chemotherapy. Resistance to chemotherapy is common. Further publications and studies will help to determine a standard therapy for this rare disease.

Simulation of methylmercury toxicity resulting from the consumption of Mediterranean red tuna fish.

The toxicity of methylmercury is sufficiently high to justify an evaluation of the risk from the consumption of contaminated food. In the method of risk assessment proposed here, distribution frequencies are assigned to the parameters in question, rather than mean values. Total body burden is estimated by numerical simulation on a digital computer. Based on recorded cases of incipient intoxication and allowing a safety factor of 10, the critical body burden has been estimated at between 5, 4 and 6 mg total mercury. From an application of this approach to the assessment of risk from Mediterranean red tuna fish consumption, it appears that there may exist high frequency consumers whose body burdens, while not in the overtly neurotoxic range, approach the computed critical level.

Protective effect of phospholipids in methylmercury inhibition of hydroxybutyrate deshydrogenase.

The inhibitory effect of methylmercury on rat liver mitochondrial D 3-hydroxybutyrate deshydrogenase--an enzyme of the inner membrane matrix, which requires lecithin as a cofactor and has thiol residues in the active site--has been investigated. Using a partially purified enzymatic extract, methylmercury inhibition of the reactivation of the apodeshydrogenase by liposomes of lecithin has been studied as a function of lecithin concentration in the incubation medium. Partial reactivation has been observed at a concentration 3 times higher than that needed to reactivate the control. The present studies support the hypothesis that phospholipids are implicated in the mechanism of methylmercury inhibition.