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Global Translational Medicine Immunohistochemistry in pituitary adenomas

typical features of acromegaly, such as enlarged extremities NFPAs, despite lacking endocrine symptoms, exhibited
in 90% of the cases. Two patients (0.5%) with Cushing significant mass effects, with 65% of patients presenting
disease had symptoms of weight gain, central obesity, with neuro-ophthalmological complications and 45%
hypertension, and purple striae. NFPAs represented 57.5% requiring surgery for compression-related symptoms.
of cases, and 60% of them were diagnosed due to mass Most NFPAs were macroadenomas (85%), underlining
effects, causing headaches, visual field defects, and optic the importance of timely surgical intervention to prevent
chiasm compression. further neurological damage.

Histopathological analysis revealed that 75% of Statistical analysis revealed a significant correlation
adenomas were eosinophilic, 15% amphophilic, and 10% between tumor size and invasiveness, with larger adenomas
basophilic. Solid growth patterns were observed in 55% (>12 mm) more frequently exhibiting Hardy Grade IV
of tumors, with 30% displaying a trabecular structure and invasion (p < 0.05). This association was particularly
15% a papillary pattern (Figures 1 and 2). Eosinophilic pronounced in eosinophilic adenomas, suggesting that
adenomas were primarily associated with PRL and GH
secretion, while basophilic adenomas were linked to
ACTH production.
Immunohistochemistry profiling revealed
monohormonal secretion in 31.5% of adenomas, with
the following distribution: 10% were prolactinomas, 5%
GH-secreting, 5% ACTH-secreting, 5% TSH-secreting,
and 5% gonadotroph adenomas. Mixed GH/PRL
adenomas comprised 37.5% of cases, while plurihormonal
adenomas accounted for 27.5%, and null-cell adenomas
represented 5%.
Eosinophilic adenomas exhibited higher rates of
invasiveness (50% invasive) compared to amphophilic
and basophilic adenomas (20% invasive) (Figure 3). This
was particularly evident in prolactinomas (43% invasive)
and somatotroph adenomas (50% invasive). IHC findings Figure 2. Pituitary adenoma with trabecular pattern in hematoxylin and
closely correlated with clinical presentations in FPAs, with eosin staining. The trabecular architecture is characterized by elongated,
acromegaly and Cushing disease confirmed by hormone ribbon-like structures of tumor cells separated by fibrous stroma or
overproduction in GH and ACTH adenomas, respectively. vascular channels. Scale bar: 1 mm, magnification: ×200.

Figure 3. The predominant type of pituitary adenomas according to cell
Figure 1. Pituitary adenoma showing solid pattern in hematoxylin and features: acidophilic pituitary adenoma with hematoxylin and eosin.
eosin staining. The solid pattern is characterized by densely packed tumor The acidophilic cells are characterized by their pink-staining cytoplasm,
cells forming sheets or nests without distinct organizational structures, which is indicative of hormone-producing cells, such as those secreting
such as trabeculae or papillae. Scale bar: 1 mm, magnification: ×200. growth hormone or prolactin. Scale bar: 1 mm, magnification: ×200.

Volume 4 Issue 2 (2025) 99 doi: 10.36922/gtm.8474