Differences Between GH- and PRL-Cosecreting and GH-Secreting Pituitary Adenomas: a Series of 604 Cases
Authors: Araujo-Castro Marta , Biagetti Betina , Menéndez Torre Edelmiro , Novoa-Testa Iría , Cordido Fernando , Pascual Corrales Eider , Rodríguez Berrocal Víctor , Guerrero-Pérez Fernando , Vicente Almudena , Percovich Juan Carlos , García Centeno Rogelio , González Laura , Ollero García María Dolores , Irigaray Echarri Ana , Moure Rodríguez María Dolores , Novo-Rodríguez Cristina , Calatayud María , Villar Rocío , Bernabéu Ignacio , Alvarez-Escola Cristina , Benítez Valderrama Pamela , Tenorio-Jimenéz Carmen , Abellán Galiana Pablo , Venegas Moreno Eva , González Molero Inmaculada , Iglesias Pedro , Blanco Concepción , Vidal-Ostos De Lara Fernando , de Miguel Paz , López Mezquita Elena , Hanzu Felicia , Aldecoa Iban , Lamas Cristina , Aznar Silvia , Aulinas Anna , Calabrese Anna , Gracia Paola , Recio-Córdova José María , Aviles Mariola , Asensio-Wandosel Diego , Sampedro Miguel , Ruz-Caracuel Ignacio , Camara Rosa , Paja Miguel , Fajardo-Montañana Carmen , Marazuela Mónica , Puig-Domingo Manel 
Published: March 2024

Abstract

Context
Few data exist about the clinical course of acromegaly, surgical and medical outcomes in patients with GH- and prolactin cosecreting pituitary adenomas (GH&PRL-PAs). Nevertheless, some series described a more aggressive clinic-radiological behavior than in growth hormone–secreting pituitary adenomas (GH-PAs).

Objective
This work aims to evaluate differences in clinical presentation and in surgical outcomes between GH-PAs and GH&PRL-PAs.

Methods
A multicenter retrospective study was conducted of 604 patients with acromegaly who underwent pituitary surgery. Patients were classified into 2 groups according to serum PRL levels at diagnosis and immunohistochemistry (IHC) for PRL: a) GH&PRL-PAs when PRL levels were above the upper limit of normal (ULN) and IHC for GH and PRL was positive or PRL levels were greater than 100 ng/dL and PRL IHC was not available (n = 130) and b) GH-PA patients who did not meet the previously mentioned criteria (n = 474).

Results
GH&PRL-PAs represented 21.5% (n = 130) of patients with acromegaly. The mean age at diagnosis was lower in GH&PRL-PAs than in GH-PAs (P &lt; .001). GH&PRL-PAs were more frequently macroadenomas (90.6% vs 77.4%; P = .001) and tended to be more invasive (33.6% vs 24.7%; P = .057) than GH-PAs. Furthermore, they had presurgical hypopituitarism more frequently (odds ratio 2.8; 95% CI, 1.83-4.38). Insulin-like growth factor ULN levels at diagnosis were lower in patients with GH&PRL-PAs (median 2.4 [interquartile range (IQR) 1.73-3.29] vs 2.7 [IQR 1.91-3.67]; P = .023). There were no differences in the immediate (41.1% vs 43.3%; P = .659) or long-term postsurgical acromegaly biochemical cure rate (53.5% vs 53.1%; P = .936) between groups. However, there was a higher incidence of permanent arginine-vasopressin deficiency (AVP-D) (7.3% vs 2.4%; P = .011) in GH&PRL-PA patients.

Conclusion
GH&PRL-PAs are responsible for 20% of acromegaly cases. These tumors are more invasive, larger, and cause hypopituitarism more frequently than GH-PAs and are diagnosed at an earlier age. The biochemical cure rate is similar between both groups, but patients with GH&PRL-PAs tend to develop permanent postsurgical AVP-D more frequently.