Nervous System
Brain, Leptomeninges - Hamartoma, Lipomatous
Narrative
Comment:
Figure 1 depicts a neurodevelopmental anomaly. This midline leptomeningeal lipomatous hamartoma is located at the base of the cingulate gyrus, immediately above the corpus callosum and septal nuclei. Consisting of normal white adipocytes, it is in the common location for a lipomatous hamartoma. The expansion of the hamartoma has had little compressive effect on adjacent structures and was not accompanied by noticeable clinical neurological signs. This type of hamartoma is uncommon in rodent studies. It is not to be confused with a lipoma or liposarcoma.
Recommendations:
Lipomatous hamartomas should be diagnosed in NTP studies and the subsite specified.
References:
Krinke GJ, Kaufmann W, Mahrous AT, Schaetti P. 2000. Morphologic characterization of spontaneous nervous system tumors in mice and rats. Toxicol Pathol 28:178-192.
Abstract: http://www.ncbi.nlm.nih.gov/pubmed/10669006
Leptomeningeal lipomatous hamartoma in an untreated male B6C3F1 mouse from a 2-year study. The arrow identifies the location of the lipomatous mass.
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Leptomeningeal lipomatous hamartoma in an untreated male B6C3F1 mouse from a 2-year study. The arrow identifies the location of the lipomatous mass.