Multiple neurofibromatosis

Yamashita M, Matsuki A, Oyama T. Anaesthetic considerations on von Recklinghausen s disease (multiple neurofibromatosis). Abnormal response to muscle relaxants. Anaesthesist 1977 26(6) 317-18. 

Neurofibromatosis type 1, a familial disorder characterized by multiple benign tumors of certain glial cells, is due to a mutation in the gene that codes for one form of GAP that regulates Ras [34], The mutation in GAP that leads to neurofibromatosis renders GAP unable to activate GTPase activity of Ras. This means that the GTP-bound form of Ras remains active for abnormally long periods of time, which leads to abnormal cellular growth. 

As mentioned earlier, G AJ has the useful property of switching RAS off. Mutations in GAP cause a common disorder called neuiofibiomatosis. Here, GAP no longer can provoke RAS to catalyze GTP hydrolysis. In its most common form, neurofibromatosis results in multiple, harmless caf au-lait spots over the skin. In its most severe and rare form, the disease results in defomriing tumors, as occurred in the case of the Elephant Man (Riccardi, 1981), To sum up, the tumors of the Elephant Man probably resulted because GAP failed to terminate the activity of RAS- Mutations in MAFKKK and MAPKK have also been foxmd that result in cancer (Stang el ai., 1997),... 

Schmale, M.C., G.T. Hensley and L.R. Udey. Multiple schwanomas in the biocolor damselfish, Pomacentrus partitas, a possible model of von Rocklinghausen neurofibromatosis. Am. J. Pathol. 112 238-241, 1983. 

The most common cutaneous nerve sheath tumors are neurofibromas often, such tumors are multiple and occur in the setting of von Recklinghausen s neurofibromatosis. Neurilemmomas (schwannomas), granular cell tumors, perineuriomas, and neurothekeomas are represented in the skin as well. ° In contrast, malignant cutaneous peripheral nerve sheath tumors are... 

About 5% to 10% of GI neuroendocrine tumors are associated with a hereditary disease. The inherited syndromes and their associated genes include multiple endocrine neoplasia type I MENl gene), neurofibromatosis type 1 NFl gene), von Hippel-Lindau disease VHL gene), and the tuberous sclerosis complex TSCl or TSC2 gene).406... 

Neurofibroma may occur as a sporadic tumor or as part of the dominantly inherited tumor syndrome called von Recklinghausen disease or neurofibromatosis-1 (NF-l).i Plexiform neurofibromas are multiple swollen fascicles that are associated with NF-1. Other nervous system signs of NF-1 are more than one neurofibroma, optic nerve glioma (more appropriately called optic nerve pilocytic astrocytoma), and malignant peripheral nerve sheath tumor with glandular or rhabdomyoblastic regions. ... 

Fig. 4.24. Plexiform neurofibromatosis. Long-axis extended-field-of-view 17-5 MHz US image over the median nerve (arrows) at the forearm in a patient with neurofibromatosis shows multiple plexiform neurofibromas (asterisks), some of which have a central hyperechoic area representing the target sign. The median nerve is markedly enlarged and shows a convoluted multinodular appearance...

Neurofibromatosis type I (NFl) patients have a wide spectrum of clinical presentations, including developmental, pigment or neoplastic aberrations of the skin, nervous system, bones, endocrine organs, blood vessels and eyes. The cardinal features of NFl are cafe an lait macules, axillary and groin fieckhng, combined with multiple peripheral and central nerve tumors [1,2],... 

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