Paraneoplastic syndromes secondary to neuroendocrine tumours

Abstract

Neuroendocrine tumours may be either benign or malignant tumours, and have the ability to synthesise and secrete biologically active substances characteristic of the cell of origin that can cause distinct clinical syndromes. The term 'paraneoplastic syndromes' (PNSs) is used to denote syndromes secondary to substances secreted from tumours not related to their specific organ or tissue of origin and/or production of autoantibodies against tumour cells; such syndromes are mainly associated with hormonal and neurological symptoms. Appreciation of the presence of such syndromes is important as clinical presentation, if not identified, may delay the diagnosis of the underlying neoplasia. Conversely, early recognition can allow for more rapid diagnosis, particularly as the coexistence of a neoplasm with a clinical or biochemical marker offers an additional determinant of tumour status/progression. PNSs can complicate the patient's clinical course, response to treatment, impact prognosis and even be confused as metastatic spread. Their diagnosis involves a multidisciplinary approach, and detailed endocrinological, neurological, radiological and histological studies are required. Correct diagnosis is essential as the treatment of choice will be different for each disorder, particularly in the case of malignant tumours; it is therefore important to develop appropriate means to correctly identify and localise these tumours. Clinical awareness and the incorporation into clinical practise of 111 In-octreotide scintigraphy, chromogranin A and other evolving biochemical marker measurement techniques have substantially contributed to the identification of patients harbouring such syndromes. Diseasespecific medical therapies are mandatory in order to prevent recurrence and/or further tumour growth. Owing to their rarity, central registration of these syndromes is very helpful in order to be able to provide evidence-based diagnostic and therapeutic approaches.

ENETS Consensus Guidelines for the Standards of Care in Neuroendocrine Tumors: Pre- and Perioperative Therapy in Patients with Neuroendocrine Tumors

“…Occasionally the substances secreted by gastrointestinal NET are not directly related to the tissue of origin and the corresponding clinical syndromes are related to these ectopically secreted compounds [54] . Appreciation of the presence of such syndromes is highly relevant, because if the clinical presentation is not identified, it may delay the diagnosis of the underlying neoplasia and lead to increased morbidity and mortality.…”

Medical management of secretory syndromes related to gastroenteropancreatic neuroendocrine tumours

“…It is possible that such transformation might be more common than currently recognised, as some of the symptoms may not be specific and difficult to recognise in patients with extensive disease. Occasionally, the substances secreted by GEP-NET are not directly related to the tissue of origin, the corresponding clinical syndromes being called paraneoplastic (Kaltsas et al 2010). A high index of suspicion for the presence of such syndromes is required, as, if the clinical presentation is missed, it may delay the diagnosis of the underlying neoplasia and lead to increased morbidity and mortality.…”

“…The most common of these syndromes encountered in patients with GEP-NETs along with their presentation and symptomatic treatment are shown in Table 4. Some of these syndromes, such as Cushing's syndrome due to ectopic adrenocorticotrophin hormone (ACTH) and hypercalcaemia due to ectopic parathyroid hormone-related peptide (PTHrP) secretion, may significantly increase the operative risk, and need to be adequately treated before any intervention (Kaltsas et al 2010, Somasundaram et al 2013.…”

Tumor neuroendocrino de estómago asociado a glomerulonefritis rápidamente progresiva

“…Un número significativo de estos síndromes por los productos de secreción, e de células neuroendócrinas, que están ampliamente dispersos en el pulmón, gastrointestinal, páncreas, glándula tiroides, médula adrenal, piel, próstata y mama [3].…”