The Cushing syndrome induced by atrial natriuretic peptide-producing thymic carcinoid

Neuroendocrine neoplasms of the thymus

Neuroendocrine neoplasms of the thymus (tNENs), including typical carcinoid, atypical carcinoid, large cell neuroendocrine carcinoma, and small cell carcinoma, are rare tumors with scarce clinical and pathological data available in the literature. They share many common features with neuroendocrine neoplasms in other organs, such as those in the lungs, while demonstrating some distinct clinical and pathological features. This review aims to give an updated overview of each category of tNENs, focusing primarily on the pathologic diagnosis and differential diagnosis of these tumors.

Ectopic Cushing's syndrome due to thymic neuroendocrine tumours: a systematic review

Knowledge of ectopic Cushing's syndrome (CS) due to thymic neuroendocrine tumours (NETs) comes from short series or single cases. Our aim is to perform a systematic review using PubMed, Embase, Scopus, Ovid Medline and Biosis Previews of all cases with ectopic CS due to thymic NETs reported in the last 40 years and describe one illustrative patient attended in our institution. Search of literature: From 162 patients, 58.6% were male and mean age was 34.6 ± 13.9 years-old. Median of symptoms until diagnosis was 6 [2-24] months and 62% had aggressive CS. Imaging was positive in 93.7% (chest X-ray), 97.8% (computed tomography), 80.7% (somatostatin receptor scintigraphy) and median tumour size was 47 [25-68.5] mm. At presentation, 18% had localized disease, 26.2% locally invasive and 55.7% advanced. Eighty-eight present underwent surgery and histological subtypes were atypical (46.7%), typical (30.4%) and carcinoma (21.7%). Tumour persisted or recurred in 70.1%, 63% received radiotherapy and 45.2% chemotherapy. Follow-up median was 26.6 [14.5-57.5] months and mortality was reported in 35.8% with median survival of 38 [19-60] months. MEN-1 mutation was referred in 3.1%. Comparatively, carcinomas had aggressive CS more frequently while atypical showed advanced disease more often. In conclusion, thymic NETs causing ectopic CS are presented as aggressive hypercortisolism in the middle aged population. The disease is commonly extended at diagnosis and persists or recurs after surgery in most patients with a short term high mortality.

Neuroendocrine tumors of the thymus and mediastinum

Neuroendocrine tumors of the thymus (tNET) and mediastinum are very rare neoplasms with scarce available data. All subtypes [typical and atypical carcinoid tumors (TC and AC), large cell neuroendocrine and small cell carcinoma (SCC)] observed elsewhere in the body occur also in the mediastinum and show only few if any organ-specific morphological differences. Although all available data suggest that the broad principles that govern the biology (and hence) the classification of these tumors in general apply also to tNET, there are a few noteworthy peculiarities related e.g., to risk factors, relative frequency and also to molecular genetic features. In this review, we will briefly summarize current knowledge on tNET with a special emphasis on shared and private features in comparison e.g., with pulmonary NET, which have traditionally been regarded the next closely related NET group.

Bronchial and Thymic Carcinoid Tumors

Bronchial and thymic carcinoids are rare. We present epidemiologic data and potential risk factors. The approach to bronchial and thymic carcinoid patients is discussed, from the initial diagnosis and evaluations to treatment. These malignancies follow staging systems of their site of origin. Because bronchial and thymic carcinoids are rare, we use many treatment strategies that have been demonstrated in gastrointestinal and pancreatic neuroendocrine tumors. The lack of information regarding efficacy in bronchial and thymic carcinoids, as well as the scarcity of therapeutic options available, demands the importance of clinical trials that include these patients.