Two familial giant pituitary adenomas associated with overweight: clinical, morphological and genetic features

Etiopathogenesis of oncocytomas

Oncocytomas are distinct tumors characterized by an abnormal accumulation of defective and (most probably) dysfunctional mitochondria in cell cytoplasm of such tumors. This particular phenotype has been studied for the last decades and the clarification of the etiopathogenic causes are still needed. Several mechanisms involved in the formation and maintenance of oncocytomas are accepted as reasonable causes, but the relevance and contribution of each one for oncocytic transformation may depend on different cancer etiopathogenic contexts. In this review, we describe the current knowledge of the etiopathogenic events that may lead to oncocytic transformation and discuss their contribution for tumor progression and mitochondrial accumulation.

Invasive Growth Hormone Producing Pituitary Adenoma With Lymphocytic Infiltration: A Case Report and Literature Review

INTRODUCTION

We have presented a rare case of growth hormone (GH) producing pituitary adenoma with lymphocytic infiltration and brain parenchyma invasion.

CASE PRESENTATION

A 37-year-old woman has presented with complaints of headache, amenorrhea and acromegalic features. Her laboratory studies showed markedly elevated levels of Insulin-like Growth Factor 1 (IGF-1), and low levels of follicle stimulating hormone and luteinizing hormone. Computerized tomography has revealed a pituitary mass without extra-sellar extension. The tumor has completely excised via trans-nasal endoscopic approach. Histologically, the tumor has diagnosed as a pituitary adenoma with GH positive cells. The serum IGF1 levels have gradually decreased to the normal range and the patient was symptom free for three and a half years when she has returned with complaint of visual impairment. The brain MRI that time has shown a supra-sellar mass growing independently into the remaining sellar part. Subsequently, surgical operation has performed via trans-nasal endoscopic approach. Histopathological and immunohistochemistry examination have revealed a rare case of growth hormone producing pituitary adenoma with brain invasion and lymphocytic infiltration.

CONCLUSIONS

The aim of this publication was to present a rare case of growth hormone producing pituitary adenoma with brain invasion and lymphocytic infiltration.

The R304X mutation of the aryl hydrocarbon receptor interacting protein gene in familial isolated pituitary adenomas: Mutational hot-spot or founder effect?

BACKGROUND

Mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene have been described in about 15% of kindreds with familial isolated pituitary adenomas and in a minority of early onset sporadic pituitary adenomas (PA). Among the AIP mutations reported so far, the R304X (AIPR304X) represents, together with the "Finnish mutation" Q14X, the most common one.

METHODS

Three AIPR304X Italian families, including a newly reported kindred, have been genotyped for 12 genetic markers surrounding the AIP gene in order to look for a potential founder effect in Italy. Disease penetrance and genotype-phenotype correlations were also addressed.

RESULTS

Analysis of chromosome 11' genetic markers revealed a common haplotype in 2 AIPR304X kindreds originating from central Italy. Overall, 17 mutations carriers were identified, including 7 patients and 10 unaffected subjects, respectively, arguing in this case for a disease penetrance of 41%. Mean age at diagnosis was 19.1±6.7 yr old, with females tending to be older than males. Though most PA were somatotropinomas (6/7), a great variability in disease severity was observed, even between subjects sharing the same at-risk haplotype.

CONCLUSION

These data provide strong evidence for a new founder effect of the AIPR304X mutation in central Italy and the observed variations in disease severity point out the role of additional genetic or environmental factors in such kindreds.

Silent familial isolated pituitary adenomas: histopathological and clinical case report

Familial isolated pituitary adenoma (FIPA) is a rare condition independent of Carney Complex or MEN1. An international multicenter study recently described 28 nonfunctioning pituitary adenomas in 26 families with only two homogeneous nonsecreting phenotype families consistent of silent GH and silent gonadotroph adenomas, respectively. We present the clinical, genetic, and morphological analysis of two silent pituitary adenomas occurring in a man and his daughter, and discuss the differential diagnosis associated with their histological, immunohistochemical, and ultrastructural features. The patients developed invasive nonsecreting macroadenomas manifesting only with compressive symptoms. Genetic analysis in the father showed no MEN-1 germ-line mutation. Tissue samples obtained after paraseptal trans-sphenoidal surgery were studied by immunohistochemistry for adenohypophyseal hormones, low molecular weight cytokeratins (CAM 5.2), proliferation markers, and anterior pituitary transcription factors (Pit-1 and SF-1) and by electron microscopy for secretory granules. The clinical, histological, and immunohistochemical features of the lesions posed a differential diagnosis between a null cell adenoma and a silent corticotroph adenoma (Type II); on the basis of immunohistochemical stains for cytokeratin and adenohypophysis cell lineage markers, tumor behavior and ultrastructural studies we concluded for the second. The reported cases represent an as yet undescribed example of homogeneous family with silent corticotroph adenomas (Type II). Our observations support the trend for more aggressive behavior in nonsecreting FIPAs as compared with sporadic adenomas.

Clinical characterization of familial isolated pituitary adenomas

CONTEXT

Familial pituitary adenomas occur rarely in the absence of multiple endocrine neoplasia type 1 (MEN1) and Carney complex (CNC).

OBJECTIVE

Our objective was to characterize the clinical and genealogical features of non-MEN1/CNC familial isolated pituitary adenomas (FIPA).

DESIGN AND SETTING

We conducted a retrospective study of clinical and genealogical characteristics of FIPA cases and performed a comparison with a sporadic population at 22 university hospitals in Belgium, Italy, France, and The Netherlands.

RESULTS

Sixty-four FIPA families including 138 affected individuals were identified [55 prolactinomas, 47 somatotropinomas, 28 nonsecreting adenomas (NS), and eight ACTH-secreting tumors]. Cases were MEN1/PRKAR1A-mutation negative. First-degree relationships predominated (75.6%) among affected individuals. A single tumor phenotype occurred in 30 families (homogeneous), and heterogeneous phenotypes occurred in 34 families. FIPA cases were younger at diagnosis than sporadic cases (P = 0.015); tumors were diagnosed earlier in the first vs. the second generation of multigenerational families. Macroadenomas were more frequent in heterogeneous vs. homogeneous FIPA families (P = 0.036). Prolactinomas from heterogeneous families were larger and had more frequent suprasellar extension (P = 0.004) than sporadic cases. Somatotropinomas occurred as isolated familial somatotropinoma cases and within heterogeneous FIPA families; isolated familial somatotropinoma cases represented 18% of FIPA cases and were younger at diagnosis than patients with sporadic somatotropinomas. Familial NS cases were younger at diagnosis (P = 0.03) and had more frequently invasive tumors (P = 0.024) than sporadic cases.

CONCLUSIONS

Homogeneous and heterogeneous expression of prolactinomas, somatotropinomas, NS, and Cushing's disease can occur within families in the absence of MEN1/CNC. FIPA and sporadic cases have differing clinical characteristics. FIPA may represent a novel endocrine neoplasia classification that requires further genetic characterization.

Bases moleculares dos adenomas hipofisários com ênfase nos somatotropinomas

Esta revisão descreve as bases moleculares dos adenomas hipofisários com ênfase nos tumores secretores de GH (somatotropinomas). São discutidos os papéis de genes de supressão tumoral (como RB1, MEN-1) e de oncogenes (como gsp, PTTG) na iniciação e progressão destes tumores. A caracterização destes marcadores moleculares pode ajudar na compreensão do comportamento tumoral, auxiliando a conduta terapêutica. Entretanto, apesar dos recentes avanços, ainda não é totalmente conhecida a seqüência de alterações genéticas envolvidas na patogênese destes adenomas.

Isolated familial somatotropinoma

The great majority of growth hormone (GH)-secreting pituitary tumors are sporadic, though a few occur with a familial aggregation, either as a component of multiple endocrine neoplasia, type 1 (MEN1) or Carney Complex, or when unassociated with other tumors, as isolated familial somatotropinomas (IFS). This report reviews the clinical and genetic information available from the 46 families reported to date with the latter syndrome. In contrast to sporadic tumors, GH-secreting tumors in IFS occur at an earlier age, especially when all affected family members are from a single generation. The IFS gene is believed to be a tumor suppressor gene, based on the presence of loss of heterozygosity. Although the gene still remains to be identified there is strong evidence for linkage to a locus of less than 10 Mb on chromosome 11q13.1-13.3.

Diagnóstico e tratamento da acromegalia no Brasil

Acromegalia é uma doença debilitante e desfigurante que, se não controlada adequadamente, reduz a expectativa de vida do paciente. Complicações cardiovasculares e respiratórias representam as principais causas de morte nos acromegálicos. Atualmente, o diagnóstico é realizado de acordo com as diretrizes do consenso de 2000: ausência de supressão do GH para um valor <1ng/mL e IGF-1 elevado. Avanços em todas as modalidades terapêuticas têm ocorrido, propiciando o controle bioquímico da doença em um número cada vez maior de pacientes. Estudos prévios mostraram que a obtenção de níveis seguros de GH (GH médio <2,5ng/mL) e de IGF-1 normal reduz a taxa de mortalidade para o normal. Em 2002, foram publicadas diretrizes para o manejo da acromegalia, o qual envolve, muitas vezes, uma abordagem multidisciplinar. Neste artigo, fazemos uma avaliação crítica do que dispomos no Brasil para seguirmos as diretrizes estabelecidas nos consensos sobre diagnóstico e tratamento da acromegalia.

Germline mutations of the MEN1 gene in Korean families with multiple endocrine neoplasia type 1 (MEN1) or MEN1-related disorders

Multiple endocrine neoplasia type 1 (MEN1) is a familial cancer syndrome characterized by the combined occurrence of tumours of the parathyroid glands, pancreatic islet cells and anterior pituitary gland. Mutation analysis of the MEN1 gene has enabled the genetic diagnosis of patients with MEN1. Two MEN1-related disorders - familial isolated hyperparathyroidism (FIHP) and familial pituitary adenoma - are considered to be variants of MEN1, or at least to be incompletely expressed variants. Germline mutations of the MEN1 gene have been reported in some with FIHP, but familial pituitary adenoma usually lacks the MEN1 mutation and has been described as a genetically distinct disorder. In this work, we investigated five Korean families with MEN1, one family with FIHP and one family with familial pituitary adenoma. Polymerase chain reaction (PCR)-based single-strand conformation polymorphism (PCR-SSCP) analysis, denaturing high-performance liquid chromatography (DHPLC) and sequencing were used to detect the MEN1 mutations. Screening of the genetic variations of the MEN1 gene revealed four germline mutations in five typical MEN1 families. All four germline mutations led to truncated proteins or a change in the amino acids of the functional domains. In this study, we identified three novel MEN1 germline mutations (969C >A, 973G >C and 1213C >T) and one previously reported mutation (200-201insAGCCC). The frequency of the MEN1 germline mutation in Korean MEN1 families (four of five; 80%) was similar to those reported previously. In accordance with previous studies, no MEN1 germline mutation was detected in two families with FIHP or familial pituitary adenoma.