Maxillary antrum is also known as maxillary sinus and is the biggest of the paranasal sinuses. Mucosal thickening within the maxillary antrum is one of the signs of sinusitis.

A lesion of the mucosal lining of the stomach is called a gastric ulcer.

Yes, mucosal is a medical term meaning related to the mucosa, or mucous membranes.

• Grade A
  Definition - At least one mucosal break no longer than 5 mm, none of which extends between the tops of the mucosal folds.
  
• Grade B
  Definition - At least one mucosal break more than 5 mm long, none of which extends between the tops of two mucosal folds.
  
• Grade C
  Definition - Mucosal breaks that extend between the tops of two or more mucosal folds, but which involve less than 75% of the mucosal circumference.
  
• Grade D
  Definition - Mucosal breaks which involve at least 75% of the mucosal circumference.

Mild mucosal thickening along the left frontal sinus is a sign of sinusitis.