Melanoma-Astrocytoma Syndrome

At a glance

It is an inherited disorder characterized by numerous cutaneous malignant melanomas associated with tumors of the nervous system, including astrocytoma, medulloblastoma, glioblastoma multiforme, ependymoma, glioma, meningioma, and acoustic neurilemmoma.

Synonym

Melanoma and Neural System Tumor Syndrome.

Incidence

The exact incidence remains unknown.

Genetic inheritance

Autosomal dominant. The gene has been mapped to 9p21 with germ-like mutation in the cyclin-dependent kinase inhibitor 2A (CDKN2A).

Pathophysiology

Chromosome region 9p21 is involved in chromosomal inversions, translocations, heterozygous deletions, and homozygous deletions in a variety of malignant cell lines. These findings suggest that 9p21 contains a tumor suppressor locus that may be involved in the genesis of several tumor types.

Diagnosis

Clinical predictive genetic testing for mutation in the CDKN2A gene is available commercially.

Clinical aspects

Generally, most individuals affected with this syndrome present with more nevi than normal, and the tendency to dysplastic transformation is significantly higher. The association with neural tumor may be higher, and more pancreatic cancers are associated.

Anesthetic considerations

The anesthesia considerations will be determined by the presence of brain tumor, its type, location, and size. Inevitably, the presence of raised intracranial pressure will dictate the conduct of anesthesia and postoperative management. The type of tumor will also impact on the preparation for anesthesia, eg, vascularization (eg, medulloblastoma), and seizures (gliomas). Anesthesia may be challenging when isolated limb perfusion is indicated to prevent cardiovascular instability, called “distributive shock,” which is caused by the injection of tumor necrosis factor.

Pharmacological implications

There are no known specific implications with this condition except for the general anesthesia rules applied when raised intracranial pressure is present. Also, pain management postoperatively will be influenced by the extend of the surgical procedure and the need for intensive care (or stepdown unit) monitoring/management.

Other conditions to be considered

Astrocytomas and cutaneous malignant melanomas are present in other well-defined syndromes such as ☞Neurofibromatosis Syndrome, ☞Turcot Syndrome, ☞Lynch Type II Cancer Syndrome, ☞Li-Fraumeni Syndrome, and ☞Tuberous Sclerosis Syndrome. They are summarized below or in their corresponding alphabetical order within the book. The difference with the clinical presentation observed with the Melanoma-Astrocytoma Syndrome and these syndromes is the disease pattern where no additional cancer types are seen as it is the case in the other ones. All of the following conditions are allelic variants of CDKN2A mutation.

• Melanoma-Pancreatic Cancer Syndrome: Atypical familial multiple mole that can be caused by mutations in the gene encoding cyclin-dependent kinase inhibitor-2A (CDKN2A). There are no specific anesthesia considerations and a standard anesthetic is indicated.

• Cutaneous Malignant Melanoma:...