The pituitary gland is divided into three parts- pars anterior, which is the anterior lobe, pars nervosa, which is the posterior lobe and an intermediate area called pars intermedia. Its cells form anastomosing cords and may be confused with the plates of the liver. It is a compact gland with little space between the parenchymal cells. But there is more space in the posterior part of  the gland than the anterior.

Differential diagnosis:  The very compact organs like liver, spleen and lymph nodes can be confused with pituitary gland. Firstly liver has plates which radiate like the spoke of bicycle wheel, pituitary gland has cells which form cords rather than plates. Spleen has distinct red and white (blue) pulps and lymph nodes have distinct cortical nodules with light staining centers called germinal centers.

Ultrastructure
Histology
Embryology
Gross anatomy