Cushing's like syndrome in typical bronchial carcinoid a case report and review of the literature

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.

Carcinoid tumors of the thymus and Cushing's syndrome: Clinicopathologic features and current best evidence regarding the cell of origin of these unusual neoplasms

It is uncertain whether thymic neuroendocrine tumors (NET) associated with Cushing's syndrome (CS) produce corticotropin-releasing hormone (CRH) and adrenocorticotropin hormone (ACTH) and whether the thymus contains ACTH and/or CRH cells that could originate NET. The clinicopathologic features of 5 typical (TC) and 6 atypical carcinoids (ATC), 10 additional non-neoplastic thymi, 6 adrenal glands with bilateral nodular hyperplasia and 8 adrenal cortical adenomas were reviewed. Representative slides were immunostained for ACTH and CRH. Four (36.4%) of the 11 patients had CS. The incidence of Masaoka stage IV was higher (p < 0.0001) in patients with ATC than TC. Only 2 (18.1%) of the 11 patients were alive at follow-up. Ten NET were CRH immunoreactive and 6 were ACTH immunoreactive. Thymic NET with CS exhibited stronger immunoreactivity for ACTH and CRH than those without CS. Non-neoplastic thymi exhibited scattered ACTH and CRH immunoreactive cells. Normal adrenal cortex and glands with bilateral nodular hyperplasia showed diffuse CRH immunoreactivity while adrenal adenomas showed no or only focal CRH immunoreactivity. Literature review showed no association between thymic NET and adrenal adenomas. The thymus contains CRH and ACTH immunoreactive cells that are probably the origin of thymic NET. Neoplasms associated with CS exhibit strong immunoreactivity for both hormones, suggesting that CRH probably plays a role in the pathogenesis of CS. As adrenals with bilateral nodular hyperplasia exhibit diffuse CRH immunoreactivity and adrenal cortical adenomas either lack this finding or show few immunoreactive cells, this marker may be useful to distinguish these lesions.