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mutational analysis associated with risk for MTC and age of prophylactic sur-

gery in these patients is summarized in the table given below.

Mutations

Age of

prophylactic

surgery

Age to screen for

pheochromocytoma

Age to screen

for PHPT

Codon 883, 918,

804–806 (highest risk)

<1 year of age 8 years of age –

Codon 634 (higher risk) <5 years of age 8 years of age 8 years of age

Codon 609, 611, 618,

620 (lesser risk)

Codon 321, 531, 532

(least risk)

>5 years of age 20 years of age 20 years of age

A basal and/or stimulated calcitonin and neck ultrasound examination should

be performed annually in individuals where prophylactic surgery for MTC is

not contemplated.

32. What is MEN4 syndrome?

Approximately, 3 % of patients with PHPT and pituitary adenoma who simu-

lates MEN1 syndrome but are negative for MEN1 gene mutation are reclas-

sified as MEN4 syndrome. These patients have CDKN1B gene mutation

instead of MEN1 gene mutation. Other tumors described in MEN4 syndrome

include pancreatic neuroendocrine tumors and adrenal tumors. The distin-

guishing features of MEN4 from MEN1 syndrome include the presence of

reproductive organ tumors like testicular cancer and neuroendocrine cervical

carcinoma.

33. What is multiple endocrine and other organ neoplasia (MEON)?

Disorders which are associated with multiple endocrine as well as non-

endocrine neoplasia like Carney’s complex, Von Hippel–Lindau disease, and

neurofibromatosis type 1 are classified under multiple endocrine and other

organ neoplasia (MEON) syndrome.

34. What is Carney’s complex?

Carney’s complex is an autosomal dominant inherited disorder, character-

ized by small pigmented cutaneous and mucosal lesions (lentigines), cardiac

and cutaneous myxomas, and the presence of multiple endocrine neoplasias

including primary pigmented nodular adrenal disease (PPNAD), pituitary

adenoma, and nodular goiter. In addition, non-endocrine tumors like fibroad-

enoma of the breast and testicular tumors have also been reported in these

patients.

11 Multiple Endocrine Neoplasia