GNAS mutated thyroid carcinoma in a patient with Mc Cune Albright syndrome.

Mc Cune-Albright syndrome (MAS) is a rare disorder defined by the triad of polyostotic fibrous dysplasia, "café au lait" skin hyperpigmentation and hyperfunctioning endocrinopathies, such as precocious puberty. MAS is caused by an activating post zygotic somatic mutation of GNAS gene, coding for the alpha-subunit of the stimulatory G protein (Gsalpha). In endocrine tissues, this mutation results in overproduction of hormones and endocrine cell hyperfunction and proliferation. Whereas the association of hyperthyroidism and thyroid adenomas is well known in MAS, the relation with thyroid carcinoma has rarely been observed. We report the occurrence of a thyroid carcinoma in an 18-years old woman with MAS, revealed by subclinical hyperthyroidism detected during her systematic annual follow-up. Ultrasound and thyroid scintigraphy revealed the presence of a nodule in the right lobe. Pathology on hemithyroidectomy revealed an unexpected thyroid follicular carcinoma. Neoplastic thyroid cells harbored the GNAS R201C activating mutation. This observation suggests that MAS may predispose patients to thyroid carcinomas and supports the importance of thyroid assessment by physical examination, hormonal blood test and ultrasound, in the follow-up of patients with MAS. Because ultrasound diagnostic is challenging in MAS, needle puncture of palpable nodules should be advised.

ALK7 expression in prolactinoma is associated with reduced prolactin and increased proliferation.

Prolactinoma represents the most frequent hormone-secreting pituitary tumours. These tumours appear in a benign form, but some of them can reach an invasive and aggressive stage through an unknown mechanism. Discovering markers to identify prolactinoma proliferative and invading character is therefore crucial to develop new diagnostic/prognostic strategies. Interestingly, members of the TGFß-Activin/BMP signalling pathways have emerged as important actors of pituitary development and adult function, but their role in prolactinomas remains to be precisely determined. Here, using a heterotopic allograft model derived from a rat prolactinoma, we report that the Activins orphan type I receptor ALK7 is ectopically expressed in prolactinomas-cells. Through immunohistological approaches, we further confirm that normal prolactin-producing cells lack ALK7-expression. Using a series of human tumour samples, we show that ALK7 expression in prolactinomas cells is evolutionary conserved between rat and human. More interestingly, our results highlight that tumours showing a robust expression of ALK7 present an increased proliferation as address by Ki67 expression and retrospective analysis of clinical data from 38 patients, presenting ALK7 as an appealing marker of prolactinoma aggressiveness. Beside this observation, our work pinpoints that the expression of prolactin is highly heterogeneous in prolactinoma cells. We further confirm the contribution of ALK7 in these observations and the existence of highly immunoreactive prolactin cells lacking ALK7 expression. Taken together, our observations suggest that Activin signalling mediated through ALK7 could therefore contribute to the hormonal heterogeneity and increased proliferation of prolactinomas.

Familial pituitary adenomas with a heterogeneous functional pattern: clinical and genetic features.

Familial pituitary adenoma is a rare syndrome which may present either as isolated lesions, or in association with other endocrine tumors, for example in the frame of multiple endocrine neoplasia (MEN-1) or Carney complex (CNC). The most frequently described forms of familial isolated pituitary adenoma (FIPA) are familial somatotropinomas or prolactinomas. Recently, some cases of familial isolated somatotropinoma have been associated with germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene. The present report shows heterogeneous FIPA with 3 subtypes of tumor in 3 individuals of the same family: somatotropinoma in the proband, giant prolactinoma in a brother, and gonadotroph cell macroadenoma in the father. A prospective survey also suggested the occurrence of a silent microadenoma in the proband's sister. Clinical screening was performed in the 3 affected members, the 4th suspected case, and 9 additional, asymptomatic relatives. They had no clinical evidence of associated endocrine lesion suggesting MEN-1 or CNC. Genetic screening for germline mutation of the MEN-1, the gene encoding the protein kinase A (PKA) type 1 alpha regulatory subunit (R1 alpha) (PRKAR1alpha) and AIP gene was negative in 2 affected members. In conclusion, these data suggest that familial pituitary adenomas can occur with a heterogeneous functional pattern that is distinguished from MEN-1 or CNC. The absence of mutation of the recently described AIP gene suggests the implication of other predisposing gene(s). Collaborative, multicentric studies are needed to further define the location of gene(s) involved in heterogeneous FIPA.

From pituitary adenoma to pituitary neuroendocrine tumor (PitNET): an International Pituitary Pathology Club proposal.

The classification of neoplasms of adenohypophysial cells is misleading because of the simplistic distinction between adenoma and carcinoma, based solely on metastatic spread and the poor reproducibility and predictive value of the definition of atypical adenomas based on the detection of mitoses or expression of Ki-67 or p53. In addition, the current classification of neoplasms of the anterior pituitary does not accurately reflect the clinical spectrum of behavior. Invasion and regrowth of proliferative lesions and persistence of hormone hypersecretion cause significant morbidity and mortality. We propose a new terminology, pituitary neuroendocrine tumor (PitNET), which is consistent with that used for other neuroendocrine neoplasms and which recognizes the highly variable impact of these tumors on patients.

Hypothalamo-pituitary sarcoidosis: a multicenter study of 24 patients.

AIM: To assess clinical features, treatment and outcome of Hypothalamo-pituitary (HP) sarcoidosis and to determine whether HP is associated with a particular clinical phenotype of sarcoidosis. DESIGN: Multicentric retrospective study. METHODS: Retrospective chart review. Each patient was matched with two controls. RESULTS: Twenty-four patients were identified (10 women, 14 men). Their median age at the sarcoidosis diagnosis was 31.5 years (range: 8-69 years). HP involvement occurred in the course of a previously known sarcoidosis in 11 cases (46%), whereas it preceded the diagnosis in 13 patients (54%). All but two patients had anterior pituitary dysfunction, 12 patients presented with diabetes insipidus. The most common hormonal features were gonadotropin deficiency (n=21), TSH deficiency (n=15) and hyperprolactinemia (n=12). Magnetic Resonance Imaging (MRI) revealed infundibulum involvement (n=8), pituitary stalk thickness (n=12) and involvement of the pituitary gland (n=14). All but two patients received prednisone. After a mean follow-up of 4 years, only two patients recovered from hormonal deficiencies. MRI abnormalities improved or disappeared in 12 cases under corticosteroid. There was no correlation between the hormonal dysfunctions and the radiologic outcomes. Patients with HP sarcoidosis had significantly more frequent sinonasal localizations and neurosarcoidosis and required a systemic treatment more frequently than controls. CONCLUSION: Although HP sarcoidosis is unusual, physicians should be aware that such specific localization could be the first manifestation of sarcoidosis. HP involvement is associated with general severity of sarcoidosis. MRI abnormalities can improve or disappear under corticosteroid treatment, but most endocrine defects are irreversible.

[Endoscopy versus microsurgery: results in a consecutive series of nonfunctioning pituitary adenomas]. / Résultats comparés de la chirurgie endoscopique et de la microchirurgie dans une série consécutive de macroadénomes hypophysaires non fonctionnels.

Microsurgical removal of nonfunctioning pituitary adenomas (NFPAs) is often subtotal. Removing the blind spots as viewed through the microscope, endoscopic surgery may improve the quality of removal. Our purpose was to compare the results of the two techniques in a series of NFPA patients operated on by a single surgeon. Thirty-six patients with newly diagnosed NFPAs were operated on using a purely endoscopic procedure and 29 with a microsurgical technique. All patients were explored pre- and postoperatively (at 3 and 6 months and then every 12 months) by endocrine assays, ophthalmologic exam, and 3D MRI. The endocrine and ophthalmologic results as well as the quality of resection and the complications from the two techniques were compared. The follow-up duration and the mean tumor volume (higher in the microsurgical group) were the only differences observed between the two groups. Tumor height and the invasion of the cavernous sinus were not different. All patients with preoperative visual impairment in the endoscopic group improved, whereas in the microsurgical group 90.9% improved, 4.5% were stabilized, and 4.5% worsened (p=ns). Regarding anterior pituitary functions, 42.8% of the patients improved in the endoscopic group, 45.7% remained stable, and 11.4% worsened compared to, respectively, 31, 44,8, and 24.1% in the microsurgical group (p=ns). Gross total removal was achieved in 86.1% for the endoscopic group and in only 65.5% for the microsurgical group (p=0.075). Morbidity was similar in the two groups. This retrospective series showed that endoscopic surgery compared to microsurgery increases the quality of NFPA removal with similar morbidity.