Clinical Significance of Granulation Pattern in Corticotroph Pituitary Adenomas

OBJECTIVE

The granulation pattern of pituitary tumors may be important to predict tumor behavior, treatment outcomes, and recurrences. Therefore, we compared densely granulated corticotroph tumor (DGCT) and sparsely granulated corticotroph tumor (SGCT) in terms of clinicopathologic findings.

MATERIAL AND METHOD

A total of 41 patients (31 females/10 males) were assessed in the study. The granulation patterns were detected by Periodic Acid-Schiff (PAS) and adrenocorticotropic hormone (ACTH) immunoreactivity. Diffuse and strong staining by PAS and ACTH were identified as DGCT, whereas faint staining by PAS and focal, weak staining by ACTH were identified as SGCT. Perinuclear ring-like patterns with low molecular weight keratin were identified as Crooke's cell tumors. DGCTs and SGCTs were compared in terms of clinical findings and treatment outcomes.

RESULTS

The majority of the patients (71%) had DGCTs (n=29); whereas 24% of the patients had SGCTs (n=10) and 5% of the patients had Crooke's cell tumors (n=2). DGCTs and SGCTs were similar in terms of age, sex, estimated duration of disease, baseline cortisol and ACTH levels. SGCTs were larger than DGCTs (p=0.034). The remissions with surgery rates were similar between the groups; however, hypothalamic-pituitaryadrenal axis recovery time was longer in SGCTs (p=0.033). Persistent disease after surgery was slightly higher in DGCTs and recurrences were frequent in SGCTs; however, the differences were not statistically significant.

CONCLUSION

DGCTs are often small microadenomas, while SGCTs are larger. Recurrences were slightly more common in SGCTs; however, further studies including larger series are needed to be able to obtain more significant results.

Screening of AIP Gene Variations in a Cohort of Turkish Patients with Young-Onset Sporadic Hormone-Secreting Pituitary Adenomas

Aims: Aryl hydrocarbon receptor-interacting protein (AIP) gene mutations have long been associated with apparently sporadic pituitary adenomas (PAs) with a prevalence range of 0-12%. The aim of this study was to evaluate the frequency of germline AIP variations in a large cohort of apparently sporadic PAs diagnosed before the age of 40 years, who did not exhibit hypercalcemia and/or MEN1 syndrome components during long-term follow-up. Materials and Methods: A total of 97 patients, diagnosed with functional PAs ≤40 years old, composed of somatotropinoma (n = 55), prolactinoma (n = 25), and corticotrophinoma (n = 17), were recruited for this study. Fifty-one of these patients [somatotropinoma (n = 30), prolactinoma (n = 15), and corticotrophinoma (n = 11)] were previously reported as AIP mutation-negative by Sanger sequencing. The entire coding sequence of the AIP gene, along with exon/intron boundaries and the untranslated regions of 41 newly recruited patients, were sequenced for germline variations. In addition, all patients were subjected to multiplex ligation-dependent probe amplification to detect copy number variations in the AIP gene. Results: The AIP c.911G>A: p.Arg304Gln (rs104894190) variant was detected in only two patients with functional PA: one with somatotropinoma [in 1/55 (1.8%)] and one with prolactinoma [in 1/25 (4%)]. None of the corticotrophinomas revealed AIP gene alterations. Thus, the overall prevalence of AIP variation was 2.1% in our cohort. Conclusions: Germline AIP gene variations among Turkish patients with apparently sporadic PAs are relatively rare among patients ≤40 years old. None of the patients in our cohort revealed any obviously pathogenic AIP variants.