Table 1.

Histological tumor classification

Tumour subtypes	Study groups
	TPAs		APAs		PCAs		Total
	Number	%	Number	%	Number	%	Number	%
Densely granulated GH-cell adenomas	5	2.5 %	3	3.1 %	0	0.0 %	8	2.6 %
Sparsely granulated GH-cell adenomas	16	8.0 %	11	11.2 %	1	10.0 %	28	9.1 %
Mixed GH/PRL-cell adenomas	9	4.5 %	6	6.1 %	0	0.0 %	15	4.9 %
PRL-cell adenomas	64	32.0 %	32	32.7 %	2	20.0 %	98	31.8 %
Densely granulated ACTH-cell adenomas	19	9.5 %	8	8.2 %	0	0.0 %	27	8.8 %
Sparsely granulated ACTH-cell adenomas	49	24.5 %	20	20.4 %	0	0.0 %	69	22.4 %
ACTH-cell adenomas, NOS	0	0.0 %	0	0.0 %	7	70.0 %	7	2.3 %
TSH-cell adenomas	3	1.5 %	2	2.0 %	0	0.0 %	5	1.6 %
FSH/LH-cell adenomas	10	5.0 %	5	5.1 %	0	0.0 %	15	4.9 %
Null cell adenomas	25	12.5 %	11	11.2 %	0	0.0 %	36	11.7 %
Total	200	100 %	98	100 %	10	100 %	308	100 %

The histological classification of each tumor analyzed in the groups of typical pituitary adenomas (TPA), atypical pituitary adenomas (APA) and pituitary carcinomas (PCA) is shown in detail. NOS not otherwise specified

GH growth hormone, PRL prolactin, ACTH adrenocorticotrophic hormone, TSH thyroid-stimulating hormone, FSH follicle-stimulating hormone, LH luteinizing hormone