Manifestaciones neuroftalmológicas en enfermedades neuroendocrinas / Neurophthalmological findings in neuroendocrine diseases

La neuroftalmología es considerada una especialidad frontera por su vínculo con otras múltiples especialidades médicas, clínicas y quirúrgicas. Los tumores de hipófisis son de tal importancia desde el punto de vista neuroftalmológico que son tratados separadamente en casi todos los textos de la especialidad. El objetivo de la presente revisión es aproximarnos, sobre la base de los conocimientos actuales, a los hallazgos neuroftalmológicos de algunas enfermedades neuroendocrinas, haciendo hincapié en dos temas fundamentales: los adenomas hipofisarios y el síndrome de neoplasias endocrinas múltiples, y demostrar además el importante papel del neuroftalmólogo en estas dos entidades. Quedan aquí evidenciadas las variadas manifestaciones neuroftalmológicas de estas entidades neuroendocrinas, el importante cometido del oftalmólogo en el diagnóstico y el ulterior seguimiento de los pacientes con adenomas hipofisarios, así como lo decisiva que puede resultar su actuación en la identificación de los hallazgos asociados al síndrome de neoplasias endocrinas múltiples tipo 2 B(AU)

Neurophthalmology is considerate frontier speciality because of their relationships with many other medical and surgical specialities. Pituitary tumors are so important from neuro-ophthalmological point of view that they appear as special chapter in text books. Our objective in the present review is to refer the neurophthalmological finfings in two main entities: pituitary adenomas and multiple endocrine neoplasia syndromes and to establish the important role of neuro-ophthalmologist in those neuroendocrine conditions. It was proved the diversity of neurophthalmological findings in neuroendocrine entities, the important role of ophthalmologist in diagnosis and pursuance of patients with pituitary adenomas and its peremptory role in screening finding associated to 2 B type multiple endocrine neoplasia syndrome(AU)

Early diagnosis of multiple endocrine neoplasia type 2B: a challenge for physicians.

BACKGROUND: The hereditary form of medullary thyroid carcinoma may occur isolated as a familial medullary thyroid carcinoma (FMTC) or as part of Multiple Endocrine Neoplasia 2A (MEN2A) and 2B (MEN2B). MEN2B is a rare syndrome, its phenotype may usually, but not always, be noted by the physician. In the infant none of the MEN2B characteristics are present, except by early gastrointestinal dysfunction caused by intestinal neuromas. When available, genetic analysis confirms the diagnosis and guides pre-operative evaluation and extent of surgery. Here we report four cases of MEN2B in which the late diagnosis had a significant impact in clinical evolution and, potentially, in overall survival. CASE REPORT: We report four cases, 2 men and 2 women, with differences in their phenotypes and with a late diagnosis. The first case has a history of severe gastrointestinal obstruction requiring a surgery intervention two days after his birth. The second told had nodules in the oral mucosa and constipation since childhood. The third case referred a history of constipation from birth until 5 months of life. The fourth has had a history of chronic constipation since childhood. DISCUSSION: New concepts have emerged since the RET oncogene was identified in 1993 as the responsible gene for hereditary medullary thyroid carcinoma. The majority of MEN2B individuals have M918T mutation in the exon 16 of RET, with a few cases having a mutation A883F or the association of V804M with E805K, Y806C or S904C mutations. The consensus classifies the RET mutation in codon 918 as of highest risk and recommends total thyroidectomy and central lymph node dissection until 6 months after birth. A fast and precise diagnosis is essential to reach these goals. The identification of early manifestations such as intestinal ganglioneuromatosis and oral mucosal neuromas should prompt the physician to initiate an investigation for multiple endocrine neoplasia type 2B. CONCLUSION: The diagnosis of MEN2B is very important to allow appropriate investigation of associated diseases and to allow counseling and appropriate screening of relatives for a RET mutation. Even patients with MEN2B, which often have typical physical features, may not be properly recognized and be followed as a sporadic case. Based on this, all suspicious cases of multiple endocrine neoplasia should undergo a molecular genetic test.

Cutaneous metastasis of pheochromocytoma in multiple endocrine neoplasia IIB.

Pheochromocytoma is a rare tumor originating from neuroectodermic cells. Only 10% of these tumors are malignant. There are many familial forms of this tumor, including multiple endocrine neoplasia type II, Von Hippel-Lindau syndrome, and neurofibromatosis type I. Skin manifestations of pheochromocytoma are rare, and cutaneous metastasis in patients with multiple endocrine neoplasia IIB has never been described. The case of a patient with multiple endocrine neoplasia IIB who presented malignant pheochromocytoma with multiple cutaneous metastasis is described.

RET oncogene mutations in medullary thyroid carcinoma in Mexican families.

BACKGROUND: Different RET oncogene mutations have been found to be associated with inherited medullary thyroid carcinoma (MTC) in the context of three different syndromes including multiple endocrine neoplasia types 2A (MEN 2A) and 2B (MEN 2B) and familial medullary thyroid carcinoma (FMTC). These mutations have been recorded in different populations, but to date there is no corresponding study in Mexican families. Our purpose was identification of RET mutations in Mexican families with inherited or sporadic MTC (SMTC) and search for RET protein expression as prognostic marker in MTC tumors. METHODS: Nine unrelated families with MTC corresponding either to two MEN 2A, three MEN 2B, or four SMTC were studied. Screening of exons 10, 11, and 13-16 of RET oncogene in DNA from circulating lymphocytes and tumor samples were analyzed. Immuno- staining for RET was performed in the corresponding tumor. RESULTS: Germline 918 ATG-->ACG RET mutation was present in three unrelated MEN 2B individuals and corresponding somatic mutation in one individual with SMTC; 634 TGC-->TTC RET mutation was detected in two related patients in an MEN 2A family and the 634 TGC-->TAC RET mutation was detected in 12 related individuals from a second MEN 2A family. RET protein expression was detected in all MTC tumors showing different staining intensity. CONCLUSIONS: RET mutations found in Mexican patients with MTC are similar to those previously reported in several MTC families worldwide. This indicates that RET mutations are highly conserved and that MTC etiology does not depend to a great extent on environmental factors or ethnic differences. Detection of RET protein in MTC tissue sections is not useful as prognostic marker.