Giant hypertrophy of gastric mucosa similar to brain surface is seen in -
Menetrier disease 

It is characterized by giant cerebriform (similar to brain surface) enlargement of rugal folds of gastric mucosa.
Enlargement of rugal folds is due to profound hyperplasia of surface mucous cells → gastric secretion & contain excessive mucus.
There is accompanying glandular atrophy → gastric disease is more common in males in the fourth to sixth decades.
The hypertrophic change may predominanty involve the body, fundus or antrum or may affect the entire stomach.
Patients develop protein-losing gastropathy accompanied hypoalbuminemia and edema.
Infrequently, the mucosal hyperplasia becomes metaplastic, providing a soil for the development of gastric carcinoma.
Peptic ulceration
Carcinoma stomach
Menetrier's disease
Liomyosarcoma