A Case of Plurihormonal Pituitary Giant Macroadenoma

Introduction Pituitary adenomas producing more than one pituitary hormone are defined as plurihormonal pituitary adenomas (PPA) according to the 2017 World Health Organization (WHO) classification of pituitary tumors (1). While the majority of functioning pituitary adenomas produce a single hormone, an imWe would like to draw the attention of the readers to Pit-1 positive giant macroadenomas in this work. A 62-year-old male patient was admitted to the hospital due to his vision loss and blurred vision in the left eye. His pituitary magnetic resonance imaging revealed the presence of a diffuse and homogeneous mass lesion originating from the pituitary gland having grade 4 invasion into the bilateral cavernous sinus and eroding the base of the sella. He consulted our department before his operation in 2016. Laboratory examination revealed that pituitary hormone levels were within normal ranges while the testosterone level [total testosterone 0.27 ng/mL (2.8-8)] was low. Pathological findings revealed a pituitary adenoma that displayed focal immunoreactivity to thyrotrophin, growth hormone, and prolactin. While the main prevalence and the basic mechanism of plurihormonal pituitary adenomas are not clear, one of the hypotheses is based on the role of divergent transcription factors such as Pit-1. According to this condition, we should perform a complete biochemical and histologic evaluation in patients with pituitary adenomas.