Controversial issues in the management of hyperprolactinemia and prolactinomas - An overview by the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism.

Prolactinomas are the most common pituitary adenomas (approximately 40% of cases), and they represent an important cause of hypogonadism and infertility in both sexes. The magnitude of prolactin (PRL) elevation can be useful in determining the etiology of hyperprolactinemia. Indeed, PRL levels > 250 ng/mL are highly suggestive of the presence of a prolactinoma. In contrast, most patients with stalk dysfunction, drug-induced hyperprolactinemia or systemic diseases present with PRL levels < 100 ng/mL. However, exceptions to these rules are not rare. On the other hand, among patients with macroprolactinomas (MACs), artificially low PRL levels may result from the so-called "hook effect". Patients harboring cystic MACs may also present with a mild PRL elevation. The screening for macroprolactin is mostly indicated for asymptomatic patients and those with apparent idiopathic hyperprolactinemia. Dopamine agonists (DAs) are the treatment of choice for prolactinomas, particularly cabergoline, which is more effective and better tolerated than bromocriptine. After 2 years of successful treatment, DA withdrawal should be considered in all cases of microprolactinomas and in selected cases of MACs. In this publication, the goal of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism (SBEM) is to provide a review of the diagnosis and treatment of hyperprolactinemia and prolactinomas, emphasizing controversial issues regarding these topics. This review is based on data published in the literature and the authors' experience.

Controversial issues in the management of hyperprolactinemia and prolactinomas - An overview by the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism

ABSTRACT Prolactinomas are the most common pituitary adenomas (approximately 40% of cases), and they represent an important cause of hypogonadism and infertility in both sexes. The magnitude of prolactin (PRL) elevation can be useful in determining the etiology of hyperprolactinemia. Indeed, PRL levels > 250 ng/mL are highly suggestive of the presence of a prolactinoma. In contrast, most patients with stalk dysfunction, drug-induced hyperprolactinemia or systemic diseases present with PRL levels < 100 ng/mL. However, exceptions to these rules are not rare. On the other hand, among patients with macroprolactinomas (MACs), artificially low PRL levels may result from the so-called "hook effect". Patients harboring cystic MACs may also present with a mild PRL elevation. The screening for macroprolactin is mostly indicated for asymptomatic patients and those with apparent idiopathic hyperprolactinemia. Dopamine agonists (DAs) are the treatment of choice for prolactinomas, particularly cabergoline, which is more effective and better tolerated than bromocriptine. After 2 years of successful treatment, DA withdrawal should be considered in all cases of microprolactinomas and in selected cases of MACs. In this publication, the goal of the Neuroendocrinology Department of the Brazilian Society of Endocrinology and Metabolism (SBEM) is to provide a review of the diagnosis and treatment of hyperprolactinemia and prolactinomas, emphasizing controversial issues regarding these topics. This review is based on data published in the literature and the authors' experience.

Angiotensin-converting enzyme inhibition increases glucose-induced insulin secretion in response to acute restraint.

There is increasing evidence suggesting involvement of the renin-angiotensin system (RAS) in carbohydrate metabolism and its response to stress. Thus, the aim of the present study was to evaluate the effects of chronic inhibition of the RAS on glucose and insulin levels during acute restraint stress. Male Holtzman rats were treated with 10 mg/kg per day enalapril solution or vehicle for 14 days. After 14 days, rats were divided into three experimental groups: enalapril + restraint (ER), vehicle + restraint (VR) and enalapril + saline (ES). Rats in the restraint groups were subjected to 30 min restraint stress, whereas rats in the ES groups were given saline infusion instead. Blood samples were collected at baseline and after 5, 10, 20 and 30 min restraint stress or saline infusion. After restraint, a hyperglycaemic response was observed in the ER and VR groups that peaked at 20 and 10 min, respectively (P < 0.05 compared with baseline). The area under the glucose curve was markedly increased in the ER and VR groups compared with that in the ES group (P < 0.05 for both). Importantly, restraint induced a marked increase in insulin secretion in the ER group compared with only a mild elevation in the VR group; insulin secretion in both groups peaked at 20 min (P < 0.05 compared with baseline). Analysis of the area under the insulin curve confirmed an increase in insulin secretion in the ER compared with the VR and ES groups (P < 0.05 for both). The results of the present study reinforce that the RAS is involved in modulating responses to stress and suggest that RAS inhibition with enalapril may increase glucose-induced insulin secretion in response to acute restraint.

[Cutaneous non-Langerhans cells histiocytoses as cause of central diabetes insipidus]. / Histiocitose cutânea não-Langerhans como causa de diabetes insípido central.

The histiocytoses are rare diseases caused by alterations in the monocyte-histiocytic series with several clinical findings. Among the cutaneous syndromes of non-Langerhans cells, xanthoma disseminatum is the only disease of this group that has been classically associated to the central diabetes insipidus (CDI). The case reported describes a 30-year-old man that two years after presenting with CDI developed non confluent disseminated cutaneous brown papular lesions throughout the body. The histopathology, immunohistochemistry, and electronic microscopy were compatible with the diagnosis of non-Langerhans histiocytoses, suggesting the diagnosis of juvenile xanthogranuloma. The endocrine-metabolic evaluation did not show other alterations besides CDI in a 10-year follow up. The magnetic resonance of hypophysis showed absence of the pituitary hyperintense sign (bright spot). The radiologic and scinthigraphic evaluation of the bones did not show the presence of osteolytic lesions. This case prints out the importance of skin examination in cases of CDI and its association with cutaneous non-Langerhans histiocytoses in a broader spectrum, rather then restricted to the cases of xanthoma disseminatum.

Histiocitose cutânea não-Langerhans como causa de diabetes insípido central / Cutaneous non-Langerhans cells histiocytoses as cause of central diabetes inspidus

As histiocitoses são doenças raras, resultantes de alterações na linhagem monocítica-histiocítica, com manifestações clínicas diversas. Entre as síndromes cutâneas de células não-Langerhans, o xantoma disseminado é a única entidade desse grupo classicamente associada ao diabetes insípido central (DIC). O caso clínico relatado refere-se a um paciente de 30 anos de idade que, dois anos após o diagnóstico de DIC, evoluiu com lesões cutâneas papulosas, eritêmato-acastanhadas, difusas, discretas e não confluentes. Os achados histológicos, imuno-histoquímicos e a microscopia eletrônica mostraram resultados compatíveis com a histiocitose de células não-Langerhans e sugestivos do xantogranuloma juvenil. A avaliação endócrino-metabólica não mostrou alterações durante o seguimento por 10 anos, com exceção do DIC. A ressonância magnética da hipófise demonstrou ausência do sinal hiperintenso (mancha brilhante) correspondente à neuro-hipófise. As radiografias e a cintilografia dos ossos não mostraram lesões osteolíticas. Este caso desperta a atenção para a importância do exame da pele nos casos de DIC e de sua associação com a histiocitose de células não-Langerhans de maneira mais ampla, e não restrita aos casos de xantoma disseminado.

The histiocytoses are rare diseases caused by alterations in the monocyte-histiocytic series with several clinical findings. Among the cutaneous syndromes of non-Langerhans cells, xanthoma disseminatum is the only disease of this group that has been classically associated to the central diabetes insipidus (CDI). The case reported describes a 30-year-old man that two years after presenting with CDI developed non confluent disseminated cutaneous brown papular lesions throughout the body. The histopathology, immunohistochemistry, and electronic microscopy were compatible with the diagnosis of non-Langerhans histiocytoses, suggesting the diagnosis of juvenile xanthogranuloma. The endocrine-metabolic evaluation did not show other alterations besides CDI in a 10-year follow up. The magnetic resonance of hypophysis showed absence of the pituitary hyperintense sign (bright spot). The radiologic and scinthigraphic evaluation of the bones did not show the presence of osteolytic lesions. This case prints out the importance of skin examination in cases of CDI and its association with cutaneous non-Langerhans histiocytoses in a broader spectrum, rather then restricted to the cases of xanthoma disseminatum.