Pathohistological classification of pituitary tumors: 10 years of experience with the German Pituitary Tumor Registry

Abstract

In 1996, the German Registry of Pituitary Tumors was founded by the Pituitary Section of the German Society of Endocrinology as a reference center for collection and consultant pathohistological studies of pituitary tumors. The experiences of the first 10 years of this registry based on 4122 cases will herein be reported. The data supplement former collections of the years 1970-1995 with 3480 surgically removed tumors or lesions of the pituitary region. The cases were studied using histology, immunostainings and in some cases also molecular pathology or electron microscopy. The adenomas were classified according to the current World Health Organization classification in the version of 2004. From 1996 on 3489 adenomas (84.6%), 5 pituitary carcinomas (0.12%), 133 craniopharyngiomas (3.2%), 39 meningiomas (0.94%), 25 metastases (0.6%), 22 chordomas (0.5%), 115 cystic non-neoplastic lesions (2.8%), and 46 inflammatory lesions (1.1%, 248 other lesions or normal tissue (6.0%)) were collected by us. The adenomas (100%) were classified into densely granulated GH cell adenomas (9.2%), sparsely granulated GH cell adenomas (6.3%), sparsely granulated prolactin (PRL) cell adenomas (8.9%), densely granulated PRL cell adenomas (0.3%), mixed GH/PRL cell adenomas (5.2%), mammosomatotropic adenomas (1.1%), acidophilic stem cell adenomas (0.2%), densely granulated ACTH cell adenomas (7.2%), sparsely granulated ACTH cell adenomas (7.9%), Crooke cell adenomas (0.03%), TSH cell adenomas (1.5%), FSH/LH cell adenomas (24.8%), null cell adenomas (19.3%), null cell adenoma, oncocytic variant (5.8%), and plurihormonal adenomas (1.3%).

Ki-67 Expression for Predicting Progression of Postoperative Residual Pituitary Adenomas: Correlations With Clinical Variables

“…8) Several studies suggest 32) that Ki-67 values greater than 3% predict more aggressive tumor behavior, and this threshold level has been carried over to the WHO criteria. The incidence of atypical adenomas varies, but these tumors are uncommon, 25,34) even among tumors with postsurgical progression or aggressive behavior, and the absence of factors with MIB-1 index higher than 3% and excessive p53 does not exclude clinically relevant aggressive behavior. Our findings indicate that MIB-1 labeling index influences the decisions regarding postoperative patient management, and shorter radiographic follow-up intervals to detect tumor re-growth and early initiation of adjuvant therapy should be considered in patients with pituitary adenomas showing MIB-1 index of AE2%.…”

Apparent diffusion coefficient and pituitary macroadenomas: pre-operative assessment of tumor atypia

“…Pituitary carcinomas, as opposed to atypical pituitary adenomas, are defined by distant cerebrospinal fluid and or systemic metastasis, and are exceptionally rare lesions that account for less than 1 % of all primary pituitary tumors [6,7]. Atypical adenomas demonstrate an intermediary behavior between nonaggressive benign adenomas and rare pituitary carcinomas, indicating a potential for recurrence rates higher than typical adenomas [6,8].…”

Low expression of secreted frizzled-related protein 2 and nuclear accumulation of β-catenin in aggressive nonfunctioning pituitary adenoma

“…Human clinically nonfunctioning pituitary adenomas (NFPAs) are defined as adenomas lacking symptoms or signs secondary to oversecretion of pituitary hormones by the tumor (2). NFPAs constitute 9-50% of all pituitary tumors and ~80% of all pituitary macroadenomas (3). Effective medical therapy has been demonstrated in FPAs (4).…”