title: Atypical carcinoid tumour of the thymus: a study of eight cases.
abstract: Atypical carcinoids of the thymus are rare neoplasms of uncertain prognosis. We have studied eight cases (six male, two female; age range 48-60 years, mean 55 years), none with evidence of a paraneoplastic neuroendocrine syndrome. Tumour size was large and ranged from 7.5 to 10 cm. Microscopically, all had a nesting/insular or trabecular pattern, eosinophilic cytoplasm, round nuclei with fine chromatin and small nucleoli. No small cell features were evident. Mitotic activity ranged from 2 to 21 per 1.52 mm2. Focal necrosis was seen in all cases. All were positive for cytokeratin (AE1/AE3, CAM 5.2) and the neuroendocrine markers NSE, synaptophysin and chromogranin; five cases were positive for calcitonin. On electronmicroscopy all contained dense core granules, often numerous. Three cases were stage I and five stage III (infiltrating lung or chest wall). Follow-up information was available in four cases (one stage I and three stage III): the stage I tumour had local recurrence and metastasis to the lung within a year whilst the three patients with stage III tumours died of liver, bone and brain metastases within 3 years.
authors.affiliation: Department of Histopathology, University of Ancona, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Valli
authors.forename: G A
authors.initials: GA
authors.lastname: Fabris
authors.forename: A
authors.initials: A
authors.lastname: Dewar
authors.forename: S
authors.initials: S
authors.lastname: Chikte
authors.forename: C
authors.initials: C
authors.lastname: Fisher
authors.forename: B
authors.initials: B
authors.lastname: Corrin
authors.forename: M N
authors.initials: MN
authors.lastname: Sheppard
mesh_terms: D002276:Carcinoid Tumor / Q000737:chemistry / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013953:Thymus Neoplasms / Q000737:chemistry / Q000473:pathology*