ACTA ENDOCRINOLOGICA (BUC)

At least one fifth of pituitary adenomas exhibit plurihormonality when using immunohistochemistry for anterior pituitary hormones. However, the correlation with clinical features is weak, without an agreement upon pathological predictors of tumor behavior. The aim was to determine the immunoreactivity for anterior pituitary hormones and alpha subunit in 276 consecutive pituitary adenomas patients, aged 22-79 years (44.3 ? 8), 154 F/ 122 M: 83 acromegalics (ACM), 173 nonfunctioning adenomas (NFA) and 20 prolactinomas (PRM) submitted to surgery via transfrontal (81) or transsphenoidal (195) along 10 years (1995-2005). In addition, clinical data, hormonal secretion and tumour size were evaluated before pituitary surgery. Local ethical committee approved the study design. The immunoreactivity performed by the avidin-biotin-complex method was evaluated for beta FSH, LH, TSH, alpha subunit, PRL and GH, using a semiquantitative scale of stained cells: strong (>20%), positive (10-20%), weak (5-10%) and negative (<5%). CT or MRI tumor size (less than 1 cm, 1-2 cm, 2-4 cm and over 4 cm on maximal diameter) were considered together with the Hardy neuroradiological stage. The results showed that 16/83 ACM, 53/173 NFA and 4/20 PRM exhibited immunoreactivity for beta FSH and LH. TSH immunoreactivity was positive in 13/83 ACM, 11/173 NFA and 1/20 PRM. Tumor size in gonadotrophin - positive group (> 10% of stained cells) was between 1-2 cm in 6 ACM, 21 NFA and 2 PRM, while positive bigger tumors (2-4 cm) were in 7 ACM, 24 NFA and 2 PRM. Giant, over 4 cm tumors were positive in 3 ACM, 8 NFA and no PRM. A similar trend of the tumor size distribution was observed in the monohormonal or null cell adenomas. In conclusion, tumor size and gonadotrophin plurihormonality are independent factors in the management of pituitary adenomas.

A 63-years old patient with severe thyrotoxicosis with cachexia and high frequency atrial fibrillation showed an inadequate secretion of TSH. A pituitary macroadenoma was revealed by computed tomography. Acute octreotide administration decreased serum TSH\r\nfrom 2.48 mU/mL to 0.06 mU/mL and T3 from 3.1 ng/mL to normal values (0.93 ng/mL) in 3 days; at the same time serum T4 remained unchanged (raised).The response to octreotide supported the diagnosis of TSH-secreting adenoma. T3 suppression test is no longer useful at present for diagnosis.Administration of long- acting somatostatin analogues (lanreotide) together with antithyroid drugs (ATD) was initially necessary. However, after removal of pituitary tumor the clinical symptoms (including atrial fibrillation) disappeared.ATD administration was no longer necessary, nor was octreotide or lanreotide. Immunohistochemistry certified that the pituitary tumor was a pure thyrotropinoma (without plurihormonal expression). Complete cure of severe thyrotoxicosis due to a TSH-secreting pituitary adenoma by pituitary surgery is possible. Thyroidectomy is not indicated.

Hyperosmolar hyperglycemic non-ketotic state is a life-threatening emergency manifested by a marked elevation of blood glucose, hyperosmolarity, and little or no ketosis. It most frequently develops in middle-aged or elderly patients, often in the setting of previously mild type 2 diabetes and in the presence of one of the established risk factors (e.g. infection, cerebrovascular accident, myocardial infarction). We present the case of a 48 years old woman with no past history of diabetes who developed hyperosmolar hyperglycemic nonketotic state after transsphenoidal surgery for a large macroprolactinoma. Despite having symptoms (secondary amenorrhoea and galactorrhoea) for many years the patient only had inconsistent medical follow-up and eventually she developed optic chiasm syndrome. She was referred for pituitary surgery performed by transsphenoidal route. After surgery there was marked improvement of the visual signs but few days after intervention the patient presented with polydipsia, polyuria and paresthesiae. Based on laboratory tests that showed a markedly elevated blood glucose level (1088 mg/dl), hyperosmolarity, no acidosis therefore, a diagnosis of hyperglycemic hyperosmolar state was made. With rehydration and insulinotherapy she recovered and the evolution was favourable over weeks with discontinuation of insulin administration. The patient still had high prolactin level after surgery (3060.3 ng/dl) so we also initiated dopamine agonist bromocriptine treatment. In addition to the well known effects of dopamine agonist upon prolactinoma it also has beneficial effects on glycemic control in diabetics (it reduces insulin resistance, both fasting and postprandial plasma glucose levels and HbA1c levels). We discuss the possible explanations of the syndrome and the effects of bromocriptine treatment.

Background: Germline aryl hydrocarbon receptor-interacting protein (AIP) mutations are found in familial isolated pituitary adenoma syndrome (FIPA) families and in a small number of sporadic pituitary adenoma (PA) patients. Although the tumorigenic mechanisms of AIP mutations are unclear, truncating mutations are considered pathogenic, but missense mutations are difficult to evaluate. p.R16H (c.47G>A) is a controversial AIP variant of unknown significance. Aim: To describe a new PA case associated with AIP p.R16H. Patients and methods: One AIP p.R16H non-functioning pituitary adenoma (NFPA) case identified by mutation sequencing screening of sporadic PA patients; 108 controls were screened for p.R16H. Results: The 38 yrs. old male NFPA patient had no family history of PA and harboured a heterozygous p.R16H variant. The proband and two brothers presented severe intellectual disability. Severe visual impairment was the initial symptom and clinical, biochemical and imaging examination demonstrated a large NFPA invading the right cavernous sinus. After transsphenoidal debulking, the remaining tumor continued growth. One of proband’s sisters was negative for p.R16H. Among controls, we identified one heterozygous p.R16H carrier, presenting a thyroid follicular neoplasm. Loss of heterozygosity analysis of the pituitary and thyroid tumors was not performed. Conclusions: We report two new occurrences of AIP p.R16H, associated with a NFPA and with a thyroid tumor. The NFPA patient was young and presented an invasive macroadenoma, features typical of AIP-mutated patients. Because the association between p.R16H and PAs has not been conclusively established, further research of p.R16H is warranted, in view of its implications for AIP genetic testing.

-

-

We present the case of a 29 years young man with acromegaly caused by a plurihormonal pituitary adenoma expressing GH, PRL, FSH and TSH within the tumoral cells. Immunoassays showed a high serum level of GH and PRL, and a serum level within normal ranges for FSH, TSH and LH. Tumoral immunohistochemistry (avidin biotin technique) was positive for GH, PRL and TSH. The presence and colocalisation of GH and FSH was shown by immunelectronmicroscopy with double immunogold techniques. The gold particles (sizes 10 nm for GH and 15 nm for FSH) were colocalised within the same translucent secretory granules of some tumor cells, ultrastructurally similar to gonadotroph cells, aside from other tumor somatotroph cells with dense secretory granules and only 10 nm antiserum GH gold particles. High cerebrospinal fluid (CSF) levels of FSH and a high ratio of CSF/serum FSH concentrations, above 1, were the first indicators that revealed, before pituitary surgery, that FSH is secreted from the pituitary tumor. TSH was a &#8220;mute&#8221; hormone, without biochemical or clinical expression outside the tumor. This pituitary adenoma showed a good response to surgery and to conventional high voltage conformational radiotherapy with the usual dose of 50 Gy. Bromocriptine and Octreotide, but not the gonadotropin releasing hormone agonist (Triptorelin), produced additional beneficial effects. It is tempting to suggest a somatogonadotroph cell as precursor of this pituitary tumor.

-

Pituitary adenomas are fully characterized only by immunohistochemistry. The technical limitations, gaps and peculiarities influence the pathology diagnosis. More and more data shows that clinically nonfunctioning pituitary adenomas could synthesize or secrete hormones or their subunits. The tumor pathology is monomorphous or polymorphous, difficult to differentiate from normal adjacent tissue. Light microscopy (LM) qualitative analysis using basic or special stains can differentiate between tumor and normal tissue and allows elimination of artifacts. Electron microscopy (EM) completes the diagnosis in selected cases. Pituitary adenomas immunohistochemistry was done by LM in 120 cases (84 ? clinically nonfunctioning adenomas ? NFA and 36 acromegalics with or without PRL secreting adenomas - ACM) using the avidine-biotin complex method. In 26 cases we determined by EM the immunoreactive cells (17 NFA and 9 ACM) using the immunogold method. We observed high tumor immunoreactivity (mono or plurihormonal) in 43/84 (51%) NFA, 13/36 (36%) ACM respectively. Serum excess hormones and tissue immunoreactivity were significantly concordant for prolactin in NFA cases and for GH, in ACM cases (p<0.05). Mute pituitary adenomas have no clinical expression of hormonal products either they produce biologically inactive components or they synthesize but do not secrete hormones in sufficient amounts to increase serum level and to determine a systemic response. A concordance between LM and EM immunoreactivity was observed only for GH in ACM patients group (p<0.05). The differences could be due to dimensions of the samples or the number of granules inside of the cells (sparsely granulated adenomas are negative or low immunoreactive at the LM level). EM evaluation of NFA identified 2 oncocytomas and 4 null cell adenomas. The complete evaluation of pituitary adenomas includ a qualitative and quantitative analysis at the LM level using special methods, validated at the EM level in order to identify clinically mute immunoreactive cells ? a possible target for specific drugs therapies in the future.