Tumor-like Lesions of the Pituitary and Sellar Region:

Silent ACTH cell adenoma in coincidence with granulomatous hypophysitis--a case report

A 44-year-old male suffered from an inactive pituitary adenoma measuring 20mm in computed tomography (CT) scan and nuclear magnetic resonance tomography (NMR). The tumor was surgically resected via the transnasal-transsphenoidal route. Surgical specimens revealed a typical, sparsely granulated adrenocorticotropic hormone (ACTH) cell adenoma, but also a granulomatous inflammation mostly in the periphery of the tumor, corresponding to a granulomatous hypophysitis. This coincidence appears to be unique and has yet not been described in the literature. Therefore, the clinical data and the pathohistologic and ultrastructural findings are presented here.

Nuclear β-Catenin Accumulation as Reliable Marker for the Differentiation Between Cystic Craniopharyngiomas and Rathke Cleft Cysts: A Clinico-Pathologic Approach

Clinical and histopathologic differentiation of cystic lesions from the sellar region, that is, craniopharyngiomas (CPs) and Rathke cleft cysts (RCCs), is challenging and has paramount importance with respect to variable clinical manifestation and adapted surgical treatment strategies in both entities. Here, we retrospectively evaluated clinico-pathologic findings in 81 patients presenting with a cystic tumor located in the sellar region. All patients underwent transsphenoidal or transcranial resections. Microscopic inspection of surgical specimens identified CP in 51 patients, and RCC in 30 patients. Amongst the panel of immunohistochemical marker proteins used for histopathologic analysis, nuclear accumulation of beta-catenin was detectable only in CP. On the basis of the histopathologic and immunohistochemical analysis, clinical presentation (sex, age, ophthalmologic, and endocrinologic deficits), imaging (tumor location, size, and calcification), as well as a description of cyst contents obtained during operation were retrospectively evaluated. In purely cystic CPs, an isointense signal was more frequent in T1-weighted magnetic resonance images and calcification of the tumor capsule in computed tomography scans. In addition, the size of RCC was smaller and this tumor entity was more often located within the sella. Aberrant (nuclear) immunohistochemical staining for beta-catenin appeared, however, as most reliable factor for the differentiation between purely cystic CPs and RCCs, whereas tumor location, tumor size, and calcification of the tumor capsule were less consistent parameters. The data are compatible with distinct pathogenic pathways associated with these related histopathologic entities.

Pituitary adenomas in childhood: development and diagnosis

Pituitary adenomas account for approximately 2.7% of all supratentorial tumors in the pediatric age range, and children are more likely than adults to develop a functioning adenoma. X chromosome inactivation studies indicate that pituitary adenomas arise from the clonal expression of a single mutated cell, and various intracellular mechanisms contribute to tumoral transformation. Functional pituitary tumors in childhood result in physical and biochemical effects of excess production of the oversecreted hormone, such as ACTH, prolactin, human growth hormone, TSH, LH, or FSH. In the clinical approach to pituitary adenomas, it is important to establish the presence of hormonal excess prior to undertaking imaging studies.

Increased abnormal pituitary findings on magnetic resonance in patients with male idiopathic hypogonadotrophic hypogonadism

Idiopathic hypogonadotropic hypogonadism (IHH) is a well-known disorder apart from its pathogenesis, which is still mostly unclear, even though a diverse subgroup of patients with hypogonadotropic hypogonadism and hyposmia/anosmia--the Kallman syndrome--have been partly linked to a mutated gene, known as kal-1 gene. In this study, we aimed to evaluate the sellar region of patients with IHH on magnetic resonance (MR). Pituitary MR of 120 male patients with IHH, diagnosed by a thorough endocrinologic assessment, were compared with pituitary MR of 49 healthy cases selected randomly who underwent detailed endocrinologic and neurologic evaluation and were assessed as healthy. Patients with IHH were diagnosed with microadenomas and irregularly contrasting pituitary (ICP), 18.2 and 10.7%, respectively. Although some anatomic variations were seen in healthy controls, microadenomas and ICP had solely been observed in patients with IHH and none in controls. Intact appearence of hypophysis in patients with IHH was significantly lower than in randomly selected healthy male subjects (p = 0.021). Mean infundibulum width of hypophysis and transverse diameter of posterior hypophysis were significantly broader in patients with IHH than in controls (both having p < 0.001), while mean hypophysis height and volume did not differ between groups. Results showed unusual incidence of pituitary abnormalities on pituitary MR in male patients with IHH. In conclusion, MR imaging is particularly useful in defining the morphological aspects of the hypothalamo - pituitary region in some endocrine disorders and other researchers might want to bear our findings in mind when performing MR evaluation of similar patient subgroups.