Comment on: Double, Synchronous Pituitary Adenomas Causing Acromegaly and Cushing’ s Disease. A Case Report and Review of Literature. Endocr Pathol 2013;24:92–99 Lorenzo Curtò & Francesco Trimarchi # Springer Science+Business Media New York 2014 To the Editor: We read with great interest the recent paper by Zieli ński et al. entitled “Double, Synchronous Pituitary Adenomas Causing Acromegaly and Cushing’ s Disease. A Case Report and Review of Literature” published in Endocrine Pathology , in which the authors reported a rare case of a 47-year-old man with double clinically active pituitary adenomas causing simul- taneous occurrence of signs and symptoms of acromegaly and Cushing’ s disease and reviewed the literature regarding multiple pituitary adenomas [1]. In a manuscript with Review of the literature published in Magnetic Resonance Imaging [2], we reported the simultaneous occurrence of multiple non-functioning pituitary microadenomas, the first case with three coexisting tumors diagnosed in vivo up to that time, in a 37-year-old woman who was referred to our outpatient clinic reporting oligomenor- rhea, significant weight gain, and persistent frontal and retroocular headache for several years. Physical examination showed moderate hirsutism and “moon face” while both basal and dynamic endocrine evaluation showed the presence of normal hypothalamic pituitary function. Magnetic resonance imaging (MRI) of hypothalamic-pituitary region revealed an enlarged sella turcica occupied by three distinct hypointense areas measuring less than 5 mm in diameter in the left, medial, and right sides of the pituitary, respectively. This finding was confirmed, 6 months later, by a second MRI that also showed a slight increase in dimensions of microadenomas. In the case report by Zieliński et al., basal and dynamic endocrine evaluation confirmed the diagnosis of active acromegaly also revealing a condition of pituitary-dependent hypercortisolism. Preoperative MRI showed a slightly enlarged and asymmetrical pituitary characterized by the presence of two separated intrasellar microadenomas with different intensity. The patient underwent transsphenoidal neurosurgery and the presence of two distinct, separated masses was confirmed. Also in our case, omitted as a reference in the article by Zieliński et al., the preoperative MRI suggestion of three different and well-defined adenomas was confirmed by transsphenoidal surgery. The occurrence of multiple pituitary adenomas is consid- ered as one of the strongest confirmations regarding the role of abnormal extrapituitary regulatory mechanisms in the patho- genesis of pituitary tumors [3]. The coexistence of multiple adenomas in the pituitary gland of the same patient supports the pathogenic role of abnormal stimulatory and/or inhibitory extrahypophiseal factors which are able to promote growth and clonal expansion of genetically altered cells also poten- tially playing a role in the recurrence of pituitary tumors [4]. In conclusion, the coexistence of two or more adenomas in a single pituitary gland is a rarely reported clinical event and a very infrequent surgical entity, but already in 1999 we de- scribed the first case of simultaneous occurrence of triple non- functioning pituitary adenomas diagnosed in vivo, where MRI allowed preoperative identification. Conflict of interest The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported. References 1. Zieliński G, Maksymowicz M, Podgórski J, Olszewski WT (2013) Double, synchronous pituitary adenomas causing acromegaly and Cushing’ s disease. A case report and review of literature. Endocr Pathol 24:92–99. L. Curtò (*) : F. Trimarchi Department of Clinical and Experimental Medicine, Section of Endocrinology, University of Messina, AOU Policlinico “G. Martino”, Via Consolare Valeria 1, 98125 Messina, Italy e-mail: curto.loren@libero.it Endocr Pathol DOI 10.1007/s12022-014-9302-2