I Know A Person With A Wound On The Face

I know a person with a wound on the face from a cancerous tumor. The wound was filled with dark yellow thick, clumpy drainage (appeared like a semi cooked scrambled egg) and smelled like an egg. The wound is located around the outer orbit of the eye and the cheek. It is approx 1.7cm deep. What could this substance be and why did it have that smell?