Endocrine Abstracts

Background: Pituitary stalk lesions (PSL) is a general term used to describe changes located in the pituitary infundibulum. Special anatomical locus makes the diagnosis difficult to establish. Most of the patients with PSL characterizes with hypopituitarism and multiple metabolic abnormalities.

Aim: To present the characteristic of patients with PSL.

Methods: We analyzed data of 35 patients (21 M/14 W) with pituitary stalk lesions on the basis of long term observation in the pediatric/adult endocrinology departments of our university. Current metabolic data were available for 19 patients. The etiologies were divided into three groups (congenital, inflammatory, neoplastic) and classified as exact, probable or unknown.

Results: The mean age of diagnosis was 28 years (s.d. 24.26). The most common causes of PSL were congenital malformations (16/35, 45.7%), an inflammatory etiology was found in 13/35 (37.1%), while neoplasms were diagnosed in 6/35 (17.1%) of patients. The exact etiology was established in 24/35 (68.6%) cases (16 congenital malformations, 5 histiocytosis, 1 Erdheim-Chester disease, 1 germinoma, 1 hypophysitis). The probable cause was suggested in 7/35 patients (20.0%) – six with the suspicion of lymphocytic hypophysitis and one with a metastasis from a disseminated neuroendocrine cancer. The origin of 4/35 PSL (11.4%) remains unknown. During hormonal assessment the most common insufficiency concerned the thyroid axis, found in 18/35 (51.4%) patients, followed by somatotropic (17/35, 48.6%), gonadal (15/35, 42.9%) and adrenal axis (11/35, 31.4% of cases) insufficiencies. 12/35 (25.7%) patients were diagnosed with diabetes insipidus. Some deficits were transient. Obesity/overweight were present in 10/19 and cachexia in 3/18 of cases. 3/18 of patients, all with lymphocytic hypophysitis, had significantly elevated systolic and diastolic blood pressure. Lipid disturbances were diagnosed in 12/19 of patients (among them in 7/11 of relatively young patients with congenital malformations, in 9/12 of patients with secondary hypothyroidism and in 10/15 of cases with somatotropic axis deficiency). 3/19 patients characterized with higher values of liver enzymes (ALT, AST, GGTP). Vitamin D deficit was found in 10/19 of cases. Hyperinsulinemia/insulin resistance were found in 6/19 of patients (only 2 of them were on hydrocortisone).

Conclusions: The diagnosis, management and treatment of the pituitary stalk lesions remain challenging. Difficulties in establishing the exact diagnosis mightbe related to the non-specific, transient characteristics of the symptoms and hormonal insufficiencies. Metabolic abnormalities in patients with hypopituitarism caused by PSL are very common. Long term observations might help better the understanding of the disease and result in improvement of management.