Yes, STRUMAE is a Scrabble word!

Letter values in Scrabble US: S 1, T 1, R 1, U 1, M 3, A 1, E 1.

Is it a valid word?

STRUMAE is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

abnormally enlarged thyroid gland; can result from underproduction or overproduction of hormone or from a deficiency of iodine in the diet
a form of tuberculosis characterized by swellings of the lymphatic glands

Also: king's evil.

Not playable in Scrabble US: THYROMEGALY.