Multiple endocrine neoplasia type 2B (MEN 2B) is an autosomal dominant disorder characterized by medullary
thyroid cancer, pheochromocytoma, neuroma and Marfanoid feature. Medullary thyroid cancer occurs in
more than 95% patients of MEN 2B and increases mortality. So, the early diagnosis of multiple endocrine
neoplasia is very important, because in the early diagnosed and treated medullary thyroid cancer, the
prognosis is excellent. This is a case of multiple endocrine neoplasia type 2B that diagnosed early by
conjunctival neuroma. A 15-year-old female patient was presented with both conjunctival masses that occurred
6 months ago. The excisional biopsy revealed conjunctival neuroma. The multiple endocrine tumor was
suspected, further evaluation was performed. Medullary thyroid cancer was confirmed by thyroid ultrasound
and fine needle aspiration. Finally, MEN type 2B was confirmed by a RET mutation genetic testing.