Biomedical subjects

G Kontogeorgos

Publications and source records attributed to G Kontogeorgos.

57 records · Page 4Linked to original sources

PubMedDate not supplied

Pituitary non-secreting macroadenoma apoplexy in an adolescent. patient report and review of the literature.

Pituitary macroadenomas are rare in children and adolescents, and when encountered are usually hormone secreting. Symptomatic pituitary non-secreting macroadenoma apoplexy in an adolescent is rare and potentially life-threatening. A 15 year-old patient is described, hospitalized due to headache, fever and photophobia 4 days prior to admission. A meningeal syndrome was postulated, based on clinical examination and cerebrospinal fluid testing. However, clinical examination and hormone testing revealed partial failure of the anterior pituitary. Computed tomography of the brain demonstrated a space-occupying lesion of the pituitary. Magnetic nuclear resonance imaging suggested the presence of a pituitary macroadenoma. Hypophysectomy was performed. Histological examination revealed an extensive infarction of a pituitary adenoma. Hormonal substitution with thyroxine and corticosteroids was administered. This report emphasizes that pituitary non-secreting macroadenoma apoplexy may rarely be the cause of headache and fever in an adolescent, thus causing difficulties in differential diagnosis from acute meningitis.

Adenoma↗

PubMedDate not supplied

Sex-linked ultrastructural dichotomy of gonadotroph adenomas of the human pituitary: an electron microscopic analysis of 145 tumors.

The ultrastructure of 145 pituitary gonadotroph adenomas was investigated with special regard to the fine structural appearance of the Golgi apparatus. Eight-five of the tumors were removed from men, 60 from women. Except for a few males, gonadotropin oversecretion was not established clinically and the diagnosis had been made solely on morphologic grounds. Owing to sex-related dimorphism, the diagnostic criteria were different for tumors of men and women. In men, approximately 50% of adenomas were structurally well-differentiated, whereas the rest of the tumors consisted of areas showing varying degrees of differentiation. The Golgi complex exhibited no signs of vacuolar transformation in any of the tumors in men. In women, more than 70% of tumors were uniformly well-differentiated, displaying vesicular transformation of Golgi complex (honeycomb Golgi complex), a characteristic diagnostic marker. In two adenomas, instead of the honeycomb Golgi complex, another unique alteration of the Golgi apparatus was encountered, comprising transformation of Golgi complex into a tripartite cloverleaflike structure with a pair of centrioles at its base. As suggested by formation of vacuoles in the center of the loops, this unusual change may be the fore-runner of honeycomb Golgi complex. Differences of the Golgi complex are viewed as morphologic expression of the fact that gonadotroph regulation and function in the two sexes are not the same.

Adenoma↗

PubMedDate not supplied

Diagnosis of pituitary adenomas on touch preparations assisted by immunocytochemistry.

Touch preparations from surgically removed pituitary adenomas were studied by both routine staining and immunocytochemistry for all anterior pituitary hormones. The results were correlated with the histologic, histochemical, immunohistochemical and ultrastructural findings. Several features were recognized, some of them applicable in diagnosing various adenoma types: high cellularity, cell monomorphism, nuclear irregularities and heterogeneity of immunoreactivity, all major diagnostic criteria of pituitary adenoma. The presence of numerous fibrous bodies associated with nuclear pleomorphism, multinucleation and peripheral displacement of nuclei, in association with growth hormone (GH) immunopositivity, represent diagnostic criteria for sparsely granulated GH cell adenoma. The "Golgi" pattern of prolactin (PRL) immunopositivity in conjunction with the small size of cell and nucleus and the presence of microcalcifications represents diagnostic features of PRL-secreting adenoma. Cytoplasmic accumulation of hyaline material in association with peripheral distribution of periodic acid-Schiff stain and adrenocorticotropic hormone immunoreactivity is characteristic of sparsely granulated corticotroph cell adenoma. Knowledge and application of the described features may contribute significantly to the diagnostic approach to pituitary adenomas.

Adenoma↗