Pituitary adenomas in adolescent patients with multiple endocrine neoplasia type 1

Giant Prolactinoma Causing Hydrocephalus and Intracranial Hypertension as First Manifestations of Multiple Endocrine Neoplasia Type 1

Context: Overall, giant prolactinomas are rare tumors (4%), especially those larger than 60 mm (1%). Despite the predominance of macroadenoma documented in multiple endocrine neoplasia type 1 (MEN1)-related prolactinoma, only three giant prolactinoma cases were described so far (size > 40 mm and prolactin > 1,000 ng/mL). None of them was larger than 60 mm or presented hydrocephalus or intracranial hypertension (ICH) as initial manifestation of MEN1. Case Description: A 21-years-old man presented with ICH as the first clinical manifestation of MEN1. He harbored a MEN1 germline mutation but refused periodic vigilance after normal hormonal screening at age 14 years. During investigation, magnetic resonance imaging (MRI) of the skull showed an expansive sellar/parasellar lesion (75 × 44 × 36 mm) with moderate to severe supratentorial obstructive hydrocephalus and an extremely high serum prolactin (PRL) of 10,800 ng/mL, without combined hypersecretion of other pituitary hormones. He was diagnosed with giant prolactinoma, and cabergoline was initiated. The patient evolved with early improvement of clinical complaints for hydrocephalus and ICH and PRL reached normal values (11 ng/mL) in association with significant tumoral shrinkage after 18 months on cabergoline. After 2 months of cabergoline, cerebrospinal fluid leakage was diagnosed and corrective surgery was provided. The mean dose of cabergoline was 3 mg/week throughout treatment. Conclusion: We reported the first case with hydrocephalus and ICH as the initial clinical manifestation of a giant prolactinoma in MEN1. From our knowledge, this is the largest MEN1-related prolactinoma reported so far. Notably, all four MEN1-related giant prolactinomas cases reported were younger than 21 years strengthening the importance to routine MEN1 genetic testing for prolactinoma in this age group. Also, they all had initial effective response with dopamine agonist ensuring this drug as first-line treatment for MEN1-related giant prolactinoma. However, the scarce number of treated patients and progression of cabergoline resistance in two of them suggest strict surveillance.

Multiple endocrine neoplasia syndromes 1 and 2: manifestations and management in childhood and adolescence

The identification of the genetic causes of the multiple endocrine neoplasia (MEN) syndromes 1 and 2, and associated genotype-phenotype relationships, has revolutionised the clinical care of affected patients. A genetic diagnosis can be made during infancy and careful clinical surveillance, coupled with early intervention, has the potential to improve both morbidity and mortality. These developments have seen the management of patients with MEN move into the arena of paediatric medicine. In this review article, we consider the genetic causes of MEN together with the clinical manifestations and management of these syndromes.

An Intronic mutation is associated with prolactinoma in a young boy, decreased penetrance in his large family, and variable effects on MEN1 mRNA and protein

Prolactinomas are rare tumors in prepubertal children. A prolactinoma in a young child may be due to sequence variants in genes that are known to cause these tumors ( MEN1, PRKAR1A, AIP). An 11-year-old boy with a macroprolactinoma was treated with cabergoline and the tumor receded. We studied the patient and his family for genetic causes of this tumor. No mutations were present in the coding sequence of PRKAR1A and AIP. A novel heterozygous substitution (IVS3-7 c>a) was identified in intron 3 of MEN1. We also found an additional PCR amplicon that incorporated the entire intron 3 of the gene (210 bp) in the patient's cDNA. The same amplicon was present with lower intensity in some of the control individuals who were not mutation carriers. Intron 3 harbors an in-frame stop codon and its incorporation is predicted to result in a prematurely terminated protein. We conclude that a novel MEN1 variation was identified in a young boy with prolactinoma and six of his relatives who did not present with prolactinoma or other MEN1 related symptoms. This novel MEN1 variation may be associated with low penetrance of the disease. The IVS3-7 c>a defect is suggested to be pathogenic because it is associated with lower menin levels in the cells of these patients, but its consequences may be mitigated by a variety of factors including changes in transcription and translation of the MEN1 gene.

Pituitary adenomas in childhood: development and diagnosis

Pituitary adenomas account for approximately 2.7% of all supratentorial tumors in the pediatric age range, and children are more likely than adults to develop a functioning adenoma. X chromosome inactivation studies indicate that pituitary adenomas arise from the clonal expression of a single mutated cell, and various intracellular mechanisms contribute to tumoral transformation. Functional pituitary tumors in childhood result in physical and biochemical effects of excess production of the oversecreted hormone, such as ACTH, prolactin, human growth hormone, TSH, LH, or FSH. In the clinical approach to pituitary adenomas, it is important to establish the presence of hormonal excess prior to undertaking imaging studies.

Advances in the treatment of prolactinomas

Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future.